Use the Chunk API consistently

This commit replaces the usage of List with Chunk
where appropriate. Summary of changes:

- The Chunk class was moved from the `org.springframework.batch.core.step.item` package to the `org.springframework.batch.item` package
- The signature of the method `ItemWriter#write(List)` was changed to `ItemWriter#write(Chunk)`
- All implementations of `ItemWriter` were updated to use the Chunk API instead of List
- All methods in the `ItemWriteListener` interface were updated to use the Chunk API instead of List
- All implementations of `ItemWriteListener` were updated to use the Chunk API instead of List
- The constructor of `ChunkRequest` was changed to accept a Chunk instead of a Collection of items
- The return type of `ChunkRequest#getItems()` was changed from List to Chunk

Resolves #3954

spring-batch-core/src/main/java/org/springframework/batch/core/ItemWriteListener.java

@@ -18,12 +18,13 @@ package org.springframework.batch.core;
 import java.util.List;
 
 import org.springframework.batch.core.scope.context.ChunkContext;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 
 /**
  * <p>
  * Listener interface for the writing of items. Implementations of this interface are
- * notified before, after, and in case of any exception thrown while writing a list of
+ * notified before, after, and in case of any exception thrown while writing a chunk of
  * items.
  * </p>
  *
@@ -42,19 +43,18 @@ import org.springframework.batch.item.ItemWriter;
 public interface ItemWriteListener<S> extends StepListener {
 
 	/**
-	 * Called before {@link ItemWriter#write(java.util.List)}
+	 * Called before {@link ItemWriter#write(Chunk)}
 	 * @param items to be written
 	 */
-	default void beforeWrite(List<? extends S> items) {
+	default void beforeWrite(Chunk<? extends S> items) {
 	}
 
 	/**
-	 * Called after {@link ItemWriter#write(java.util.List)}. This is called before any
-	 * transaction is committed, and before
-	 * {@link ChunkListener#afterChunk(ChunkContext)}.
+	 * Called after {@link ItemWriter#write(Chunk)}. This is called before any transaction
+	 * is committed, and before {@link ChunkListener#afterChunk(ChunkContext)}.
 	 * @param items written items
 	 */
-	default void afterWrite(List<? extends S> items) {
+	default void afterWrite(Chunk<? extends S> items) {
 	}
 
 	/**
@@ -64,7 +64,7 @@ public interface ItemWriteListener<S> extends StepListener {
 	 * @param exception thrown from {@link ItemWriter}
 	 * @param items attempted to be written.
 	 */
-	default void onWriteError(Exception exception, List<? extends S> items) {
+	default void onWriteError(Exception exception, Chunk<? extends S> items) {
 	}
 
 }

spring-batch-core/src/main/java/org/springframework/batch/core/annotation/AfterWrite.java

@@ -27,12 +27,14 @@ import org.springframework.batch.item.ItemWriter;
 
 /**
  * Marks a method to be called after an item is passed to an {@link ItemWriter}. Note that
- * this annotation takes a {@link List} because Spring Batch generally processes a group
- * of items (for the sake of efficiency).<br>
+ * this annotation takes a {@link org.springframework.batch.item.Chunk} because Spring
+ * Batch generally processes a group of items (for the sake of efficiency).<br>
  * <br>
- * Expected signature: void afterWrite({@link List}&lt;? extends S&gt; items)
+ * Expected signature: void afterWrite({@link org.springframework.batch.item.Chunk}&lt;?
+ * extends S&gt; items)
  *
  * @author Lucas Ward
+ * @author Mahmoud Ben Hassine
  * @since 2.0
  * @see ItemWriteListener
  */

spring-batch-core/src/main/java/org/springframework/batch/core/annotation/BeforeWrite.java

@@ -26,11 +26,13 @@ import org.springframework.batch.core.ItemWriteListener;
 import org.springframework.batch.item.ItemWriter;
 
 /**
- * Marks a method to be called before an item is passed to an {@link ItemWriter}. <br>
+ * Marks a method to be called before a chunk is passed to an {@link ItemWriter}. <br>
  * <br>
- * Expected signature: void beforeWrite({@link List}&lt;? extends S&gt; items)
+ * Expected signature: void beforeWrite({@link org.springframework.batch.item.Chunk}&lt;?
+ * extends S&gt; items)
  *
  * @author Lucas Ward
+ * @author Mahmoud Ben Hassine
  * @since 2.0
  * @see ItemWriteListener
  */

spring-batch-core/src/main/java/org/springframework/batch/core/annotation/OnWriteError.java

@@ -27,13 +27,14 @@ import org.springframework.batch.item.ItemWriter;
 
 /**
  * Marks a method to be called if an exception is thrown by an {@link ItemWriter}. Note
- * that this annotation takes a {@link List} because Spring Batch generally processes a
- * group of items (for the sake of efficiency).<br>
+ * that this annotation takes a {@link org.springframework.batch.item.Chunk} because
+ * Spring Batch generally processes a group of items (for the sake of efficiency).<br>
  * <br>
- * Expected signature: void onWriteError({@link Exception} exception, {@link List}&lt;?
- * extends S&gt; items)
+ * Expected signature: void onWriteError({@link Exception} exception,
+ * {@link org.springframework.batch.item.Chunk}&lt;? extends S&gt; items)
  *
  * @author Lucas Ward
+ * @author Mahmoud Ben Hassine
  * @since 2.0
  * @see ItemWriteListener
  */

spring-batch-core/src/main/java/org/springframework/batch/core/listener/CompositeItemWriteListener.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2013 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,11 +19,13 @@ import java.util.Iterator;
 import java.util.List;
 
 import org.springframework.batch.core.ItemWriteListener;
+import org.springframework.batch.item.Chunk;
 import org.springframework.core.Ordered;
 
 /**
  * @author Lucas Ward
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  *
  */
 public class CompositeItemWriteListener<S> implements ItemWriteListener<S> {
@@ -50,10 +52,10 @@ public class CompositeItemWriteListener<S> implements ItemWriteListener<S> {
 	/**
 	 * Call the registered listeners in reverse order, respecting and prioritising those
 	 * that implement {@link Ordered}.
-	 * @see ItemWriteListener#afterWrite(java.util.List)
+	 * @see ItemWriteListener#afterWrite(Chunk)
 	 */
 	@Override
-	public void afterWrite(List<? extends S> items) {
+	public void afterWrite(Chunk<? extends S> items) {
 		for (Iterator<ItemWriteListener<? super S>> iterator = listeners.reverse(); iterator.hasNext();) {
 			ItemWriteListener<? super S> listener = iterator.next();
 			listener.afterWrite(items);
@@ -63,10 +65,10 @@ public class CompositeItemWriteListener<S> implements ItemWriteListener<S> {
 	/**
 	 * Call the registered listeners in order, respecting and prioritising those that
 	 * implement {@link Ordered}.
-	 * @see ItemWriteListener#beforeWrite(List)
+	 * @see ItemWriteListener#beforeWrite(Chunk)
 	 */
 	@Override
-	public void beforeWrite(List<? extends S> items) {
+	public void beforeWrite(Chunk<? extends S> items) {
 		for (Iterator<ItemWriteListener<? super S>> iterator = listeners.iterator(); iterator.hasNext();) {
 			ItemWriteListener<? super S> listener = iterator.next();
 			listener.beforeWrite(items);
@@ -76,10 +78,10 @@ public class CompositeItemWriteListener<S> implements ItemWriteListener<S> {
 	/**
 	 * Call the registered listeners in reverse order, respecting and prioritising those
 	 * that implement {@link Ordered}.
-	 * @see ItemWriteListener#onWriteError(Exception, List)
+	 * @see ItemWriteListener#onWriteError(Exception, Chunk)
 	 */
 	@Override
-	public void onWriteError(Exception ex, List<? extends S> items) {
+	public void onWriteError(Exception ex, Chunk<? extends S> items) {
 		for (Iterator<ItemWriteListener<? super S>> iterator = listeners.reverse(); iterator.hasNext();) {
 			ItemWriteListener<? super S> listener = iterator.next();
 			listener.onWriteError(ex, items);

spring-batch-core/src/main/java/org/springframework/batch/core/listener/MulticasterBatchListener.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2021 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -28,6 +28,7 @@ import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.StepExecutionListener;
 import org.springframework.batch.core.StepListener;
 import org.springframework.batch.core.scope.context.ChunkContext;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemStream;
 import org.springframework.lang.Nullable;
 
@@ -241,10 +242,10 @@ public class MulticasterBatchListener<T, S> implements StepExecutionListener, Ch
 	}
 
 	/**
-	 * @see ItemWriteListener#afterWrite(List)
+	 * @see ItemWriteListener#afterWrite(Chunk)
 	 */
 	@Override
-	public void afterWrite(List<? extends S> items) {
+	public void afterWrite(Chunk<? extends S> items) {
 		try {
 			itemWriteListener.afterWrite(items);
 		}
@@ -254,10 +255,10 @@ public class MulticasterBatchListener<T, S> implements StepExecutionListener, Ch
 	}
 
 	/**
-	 * @see ItemWriteListener#beforeWrite(List)
+	 * @see ItemWriteListener#beforeWrite(Chunk)
 	 */
 	@Override
-	public void beforeWrite(List<? extends S> items) {
+	public void beforeWrite(Chunk<? extends S> items) {
 		try {
 			itemWriteListener.beforeWrite(items);
 		}
@@ -267,10 +268,10 @@ public class MulticasterBatchListener<T, S> implements StepExecutionListener, Ch
 	}
 
 	/**
-	 * @see ItemWriteListener#onWriteError(Exception, List)
+	 * @see ItemWriteListener#onWriteError(Exception, Chunk)
 	 */
 	@Override
-	public void onWriteError(Exception ex, List<? extends S> items) {
+	public void onWriteError(Exception ex, Chunk<? extends S> items) {
 		try {
 			itemWriteListener.onWriteError(ex, items);
 		}

spring-batch-core/src/main/java/org/springframework/batch/core/listener/StepListenerMetaData.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -46,6 +46,7 @@ import org.springframework.batch.core.annotation.OnSkipInRead;
 import org.springframework.batch.core.annotation.OnSkipInWrite;
 import org.springframework.batch.core.annotation.OnWriteError;
 import org.springframework.batch.core.scope.context.ChunkContext;
+import org.springframework.batch.item.Chunk;
 
 /**
  * Enumeration for {@link StepListener} meta data, which ties together the names of
@@ -72,10 +73,10 @@ public enum StepListenerMetaData implements ListenerMetaData {
 			Object.class),
 	ON_PROCESS_ERROR("onProcessError", "on-process-error-method", OnProcessError.class, ItemProcessListener.class,
 			Object.class, Exception.class),
-	BEFORE_WRITE("beforeWrite", "before-write-method", BeforeWrite.class, ItemWriteListener.class, List.class),
-	AFTER_WRITE("afterWrite", "after-write-method", AfterWrite.class, ItemWriteListener.class, List.class),
+	BEFORE_WRITE("beforeWrite", "before-write-method", BeforeWrite.class, ItemWriteListener.class, Chunk.class),
+	AFTER_WRITE("afterWrite", "after-write-method", AfterWrite.class, ItemWriteListener.class, Chunk.class),
 	ON_WRITE_ERROR("onWriteError", "on-write-error-method", OnWriteError.class, ItemWriteListener.class,
-			Exception.class, List.class),
+			Exception.class, Chunk.class),
 	ON_SKIP_IN_READ("onSkipInRead", "on-skip-in-read-method", OnSkipInRead.class, SkipListener.class, Throwable.class),
 	ON_SKIP_IN_PROCESS("onSkipInProcess", "on-skip-in-process-method", OnSkipInProcess.class, SkipListener.class,
 			Object.class, Throwable.class),

spring-batch-core/src/main/java/org/springframework/batch/core/step/item/ChunkOrientedTasklet.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2019 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,7 @@ import org.apache.commons.logging.LogFactory;
 import org.springframework.batch.core.StepContribution;
 import org.springframework.batch.core.scope.context.ChunkContext;
 import org.springframework.batch.core.step.tasklet.Tasklet;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.repeat.RepeatStatus;
 import org.springframework.lang.Nullable;
 
@@ -28,6 +29,7 @@ import org.springframework.lang.Nullable;
  * A {@link Tasklet} implementing variations on read-process-write item handling.
  *
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  * @param <I> input item type
  */
 public class ChunkOrientedTasklet<I> implements Tasklet {

spring-batch-core/src/main/java/org/springframework/batch/core/step/item/ChunkProcessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2007 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,9 +17,10 @@
 package org.springframework.batch.core.step.item;
 
 import org.springframework.batch.core.StepContribution;
+import org.springframework.batch.item.Chunk;
 
 /**
- * Interface defined for processing {@link Chunk}s.
+ * Interface defined for processing {@link org.springframework.batch.item.Chunk}s.
  *
  * @since 2.0
  */

spring-batch-core/src/main/java/org/springframework/batch/core/step/item/ChunkProvider.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2007 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,10 +17,11 @@
 package org.springframework.batch.core.step.item;
 
 import org.springframework.batch.core.StepContribution;
+import org.springframework.batch.item.Chunk;
 
 /**
- * Interface for providing {@link Chunk}s to be processed, used by the
- * {@link ChunkOrientedTasklet}
+ * Interface for providing {@link org.springframework.batch.item.Chunk}s to be processed,
+ * used by the {@link ChunkOrientedTasklet}
  *
  * @since 2.0
  * @see ChunkOrientedTasklet

spring-batch-core/src/main/java/org/springframework/batch/core/step/item/DefaultItemFailureHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2008 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,7 @@ import java.util.List;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.springframework.batch.core.listener.ItemListenerSupport;
+import org.springframework.batch.item.Chunk;
 
 /**
  * Default implementation of the {@link ItemListenerSupport} class that writes all
@@ -28,6 +29,7 @@ import org.springframework.batch.core.listener.ItemListenerSupport;
  * object.
  *
  * @author Lucas Ward
+ * @author Mahmoud Ben Hassine
  *
  */
 public class DefaultItemFailureHandler extends ItemListenerSupport<Object, Object> {
@@ -45,7 +47,7 @@ public class DefaultItemFailureHandler extends ItemListenerSupport<Object, Objec
 	}
 
 	@Override
-	public void onWriteError(Exception ex, List<? extends Object> item) {
+	public void onWriteError(Exception ex, Chunk<? extends Object> item) {
 		try {
 			logger.error("Error encountered while writing item: [ " + item + "]", ex);
 		}

spring-batch-core/src/main/java/org/springframework/batch/core/step/item/FaultTolerantChunkProcessor.java

@@ -34,8 +34,10 @@ import org.springframework.batch.core.step.skip.NonSkippableProcessException;
 import org.springframework.batch.core.step.skip.SkipLimitExceededException;
 import org.springframework.batch.core.step.skip.SkipListenerFailedException;
 import org.springframework.batch.core.step.skip.SkipPolicy;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemProcessor;
 import org.springframework.batch.item.ItemWriter;
+import org.springframework.batch.item.SkipWrapper;
 import org.springframework.classify.BinaryExceptionClassifier;
 import org.springframework.classify.Classifier;
 import org.springframework.retry.ExhaustedRetryException;
@@ -337,7 +339,7 @@ public class FaultTolerantChunkProcessor<I, O> extends SimpleChunkProcessor<I, O
 					Timer.Sample sample = BatchMetrics.createTimerSample();
 					String status = BatchMetrics.STATUS_SUCCESS;
 					try {
-						doWrite(outputs.getItems());
+						doWrite(outputs);
 					}
 					catch (Exception e) {
 						status = BatchMetrics.STATUS_FAILURE;
@@ -590,7 +592,7 @@ public class FaultTolerantChunkProcessor<I, O> extends SimpleChunkProcessor<I, O
 			}
 		}
 
-		List<O> items = Collections.singletonList(outputIterator.next());
+		Chunk<O> items = Chunk.of(outputIterator.next());
 		inputIterator.next();
 		try {
 			writeItems(items);

spring-batch-core/src/main/java/org/springframework/batch/core/step/item/FaultTolerantChunkProvider.java

@@ -23,6 +23,7 @@ import org.springframework.batch.core.step.skip.SkipException;
 import org.springframework.batch.core.step.skip.SkipListenerFailedException;
 import org.springframework.batch.core.step.skip.SkipPolicy;
 import org.springframework.batch.core.step.skip.SkipPolicyFailedException;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemReader;
 import org.springframework.batch.repeat.RepeatOperations;
 import org.springframework.classify.BinaryExceptionClassifier;

spring-batch-core/src/main/java/org/springframework/batch/core/step/item/SimpleChunkProcessor.java

@@ -26,6 +26,7 @@ import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.StepListener;
 import org.springframework.batch.core.listener.MulticasterBatchListener;
 import org.springframework.batch.core.observability.BatchMetrics;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemProcessor;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.beans.factory.InitializingBean;
@@ -145,7 +146,7 @@ public class SimpleChunkProcessor<I, O> implements ChunkProcessor<I>, Initializi
 	 * @param items list of items to be written.
 	 * @throws Exception thrown if error occurs.
 	 */
-	protected final void doWrite(List<O> items) throws Exception {
+	protected final void doWrite(Chunk<O> items) throws Exception {
 
 		if (itemWriter == null) {
 			return;
@@ -167,7 +168,7 @@ public class SimpleChunkProcessor<I, O> implements ChunkProcessor<I>, Initializi
 	 * Call the listener's after write method.
 	 * @param items list of items that were just written.
 	 */
-	protected final void doAfterWrite(List<O> items) {
+	protected final void doAfterWrite(Chunk<O> items) {
 		listener.afterWrite(items);
 	}
 
@@ -176,7 +177,7 @@ public class SimpleChunkProcessor<I, O> implements ChunkProcessor<I>, Initializi
 	 * @param e exception that occurred.
 	 * @param items list of items that failed to be written.
 	 */
-	protected final void doOnWriteError(Exception e, List<O> items) {
+	protected final void doOnWriteError(Exception e, Chunk<O> items) {
 		listener.onWriteError(e, items);
 	}
 
@@ -184,7 +185,7 @@ public class SimpleChunkProcessor<I, O> implements ChunkProcessor<I>, Initializi
 	 * @param items list of items to be written.
 	 * @throws Exception thrown if error occurs.
 	 */
-	protected void writeItems(List<O> items) throws Exception {
+	protected void writeItems(Chunk<O> items) throws Exception {
 		if (itemWriter != null) {
 			itemWriter.write(items);
 		}
@@ -267,10 +268,10 @@ public class SimpleChunkProcessor<I, O> implements ChunkProcessor<I>, Initializi
 	}
 
 	/**
-	 * Simple implementation delegates to the {@link #doWrite(List)} method and increments
-	 * the write count in the contribution. Subclasses can handle more complicated
-	 * scenarios, e.g.with fault tolerance. If output items are skipped they should be
-	 * removed from the inputs as well.
+	 * Simple implementation delegates to the {@link #doWrite(Chunk)} method and
+	 * increments the write count in the contribution. Subclasses can handle more
+	 * complicated scenarios, e.g.with fault tolerance. If output items are skipped they
+	 * should be removed from the inputs as well.
 	 * @param contribution the current step contribution
 	 * @param inputs the inputs that gave rise to the outputs
 	 * @param outputs the outputs to write
@@ -280,7 +281,7 @@ public class SimpleChunkProcessor<I, O> implements ChunkProcessor<I>, Initializi
 		Timer.Sample sample = BatchMetrics.createTimerSample();
 		String status = BatchMetrics.STATUS_SUCCESS;
 		try {
-			doWrite(outputs.getItems());
+			doWrite(outputs);
 		}
 		catch (Exception e) {
 			/*

spring-batch-core/src/main/java/org/springframework/batch/core/step/item/SimpleChunkProvider.java

@@ -28,6 +28,7 @@ import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.StepListener;
 import org.springframework.batch.core.listener.MulticasterBatchListener;
 import org.springframework.batch.core.observability.BatchMetrics;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemReader;
 import org.springframework.batch.repeat.RepeatCallback;
 import org.springframework.batch.repeat.RepeatContext;

spring-batch-core/src/test/java/org/springframework/batch/core/configuration/xml/DummyItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2009-2012 the original author or authors.
+ * Copyright 2009-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,16 +17,18 @@ package org.springframework.batch.core.configuration.xml;
 
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 
 /**
  * @author Dan Garrette
+ * @author Mahmoud Ben Hassine
  * @since 2.0
  */
 public class DummyItemWriter implements ItemWriter<Object> {
 
 	@Override
-	public void write(List<? extends Object> items) throws Exception {
+	public void write(Chunk<? extends Object> items) throws Exception {
 	}
 
 }

spring-batch-core/src/test/java/org/springframework/batch/core/configuration/xml/TestPojoListener.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010 the original author or authors.
+ * Copyright 2010-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,11 +18,12 @@ package org.springframework.batch.core.configuration.xml;
 import java.util.List;
 
 import org.springframework.batch.core.annotation.AfterWrite;
+import org.springframework.batch.item.Chunk;
 
 public class TestPojoListener extends AbstractTestComponent {
 
 	@AfterWrite
-	public void after(List<Object> items) {
+	public void after(Chunk<Object> items) {
 		executed = true;
 	}
 

spring-batch-core/src/test/java/org/springframework/batch/core/configuration/xml/TestWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2012 the original author or authors.
+ * Copyright 2008-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,12 +17,13 @@ package org.springframework.batch.core.configuration.xml;
 
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 
 public class TestWriter extends AbstractTestComponent implements ItemWriter<String> {
 
 	@Override
-	public void write(List<? extends String> items) throws Exception {
+	public void write(Chunk<? extends String> items) throws Exception {
 		executed = true;
 	}
 

spring-batch-core/src/test/java/org/springframework/batch/core/launch/EmptyItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2013 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,8 @@ import java.util.List;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.support.transaction.TransactionAwareProxyFactory;
 import org.springframework.beans.factory.InitializingBean;
@@ -49,7 +51,7 @@ public class EmptyItemWriter<T> implements ItemWriter<T>, InitializingBean {
 	}
 
 	@Override
-	public void write(List<? extends T> items) {
+	public void write(Chunk<? extends T> items) {
 		for (T data : items) {
 			if (!failed && list.size() == failurePoint) {
 				failed = true;

spring-batch-core/src/test/java/org/springframework/batch/core/listener/CompositeItemWriteListenerTests.java

@@ -24,10 +24,12 @@ import java.util.List;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.springframework.batch.core.ItemWriteListener;
+import org.springframework.batch.item.Chunk;
 
 /**
  * @author Lucas Ward
  * @author Will Schipp
+ * @author Mahmoud Ben Hassine
  *
  */
 class CompositeItemWriteListenerTests {
@@ -46,21 +48,21 @@ class CompositeItemWriteListenerTests {
 
 	@Test
 	void testBeforeWrite() {
-		List<Object> item = Collections.singletonList(new Object());
+		Chunk<Object> item = Chunk.of(new Object());
 		listener.beforeWrite(item);
 		compositeListener.beforeWrite(item);
 	}
 
 	@Test
 	void testAfterWrite() {
-		List<Object> item = Collections.singletonList(new Object());
+		Chunk<Object> item = Chunk.of(new Object());
 		listener.afterWrite(item);
 		compositeListener.afterWrite(item);
 	}
 
 	@Test
 	void testOnWriteError() {
-		List<Object> item = Collections.singletonList(new Object());
+		Chunk<Object> item = Chunk.of(new Object());
 		Exception ex = new Exception();
 		listener.onWriteError(ex, item);
 		compositeListener.onWriteError(ex, item);
@@ -73,7 +75,7 @@ class CompositeItemWriteListenerTests {
 				add(listener);
 			}
 		});
-		List<Object> item = Collections.singletonList(new Object());
+		Chunk<Object> item = Chunk.of(new Object());
 		listener.beforeWrite(item);
 		compositeListener.beforeWrite(item);
 	}

spring-batch-core/src/test/java/org/springframework/batch/core/listener/ItemListenerErrorTests.java

@@ -37,6 +37,7 @@ import org.springframework.batch.core.configuration.annotation.JobBuilderFactory
 import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
 import org.springframework.batch.core.launch.JobLauncher;
 import org.springframework.batch.core.launch.support.RunIdIncrementer;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemProcessor;
 import org.springframework.batch.item.ItemReader;
 import org.springframework.batch.item.ItemWriter;
@@ -175,7 +176,7 @@ class ItemListenerErrorTests {
 		private boolean goingToFail = false;
 
 		@Override
-		public void write(List<? extends String> items) throws Exception {
+		public void write(Chunk<? extends String> items) throws Exception {
 			if (goingToFail) {
 				throw new RuntimeException("failure in the writer");
 			}
@@ -294,21 +295,21 @@ class ItemListenerErrorTests {
 		}
 
 		@Override
-		public void beforeWrite(List<? extends String> items) {
+		public void beforeWrite(Chunk<? extends String> items) {
 			if (methodToThrowExceptionFrom.equals("beforeWrite")) {
 				throw new RuntimeException("beforeWrite caused this Exception");
 			}
 		}
 
 		@Override
-		public void afterWrite(List<? extends String> items) {
+		public void afterWrite(Chunk<? extends String> items) {
 			if (methodToThrowExceptionFrom.equals("afterWrite")) {
 				throw new RuntimeException("afterWrite caused this Exception");
 			}
 		}
 
 		@Override
-		public void onWriteError(Exception ex, List<? extends String> item) {
+		public void onWriteError(Exception ex, Chunk<? extends String> item) {
 			if (methodToThrowExceptionFrom.equals("onWriteError")) {
 				throw new RuntimeException("onWriteError caused this Exception");
 			}

spring-batch-core/src/test/java/org/springframework/batch/core/listener/MulticasterBatchListenerTests.java

@@ -38,6 +38,7 @@ import org.springframework.batch.core.annotation.BeforeProcess;
 import org.springframework.batch.core.annotation.BeforeRead;
 import org.springframework.batch.core.annotation.BeforeWrite;
 import org.springframework.batch.core.scope.context.ChunkContext;
+import org.springframework.batch.item.Chunk;
 import org.springframework.lang.Nullable;
 
 /**
@@ -703,7 +704,7 @@ class MulticasterBatchListenerTests {
 		 * (java.util.List)
 		 */
 		@Override
-		public void afterWrite(List<? extends String> items) {
+		public void afterWrite(Chunk<? extends String> items) {
 			count++;
 			if (error) {
 				throw new RuntimeException("listener error");
@@ -718,7 +719,7 @@ class MulticasterBatchListenerTests {
 		 * (java.util.List)
 		 */
 		@Override
-		public void beforeWrite(List<? extends String> items) {
+		public void beforeWrite(Chunk<? extends String> items) {
 			count++;
 			if (error) {
 				throw new RuntimeException("listener error");
@@ -733,7 +734,7 @@ class MulticasterBatchListenerTests {
 		 * (java.lang.Exception, java.util.List)
 		 */
 		@Override
-		public void onWriteError(Exception exception, List<? extends String> items) {
+		public void onWriteError(Exception exception, Chunk<? extends String> items) {
 			count++;
 			if (error) {
 				throw new RuntimeException("listener error");

spring-batch-core/src/test/java/org/springframework/batch/core/listener/StepListenerFactoryBeanTests.java

@@ -52,6 +52,7 @@ import org.springframework.batch.core.annotation.OnReadError;
 import org.springframework.batch.core.annotation.OnWriteError;
 import org.springframework.batch.core.configuration.xml.AbstractTestComponent;
 import org.springframework.batch.core.scope.context.ChunkContext;
+import org.springframework.batch.item.Chunk;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.core.Ordered;
 import org.springframework.lang.Nullable;
@@ -66,6 +67,7 @@ import static org.springframework.batch.core.listener.StepListenerMetaData.AFTER
 
 /**
  * @author Lucas Ward
+ * @author Mahmoud Ben Hassine
  *
  */
 class StepListenerFactoryBeanTests {
@@ -87,7 +89,7 @@ class StepListenerFactoryBeanTests {
 		// factoryBean.setMetaDataMap(metaDataMap);
 		String readItem = "item";
 		Integer writeItem = 2;
-		List<Integer> writeItems = Arrays.asList(writeItem);
+		Chunk<Integer> writeItems = Chunk.of(writeItem);
 		StepListener listener = (StepListener) factoryBean.getObject();
 		((StepExecutionListener) listener).beforeStep(stepExecution);
 		((StepExecutionListener) listener).afterStep(stepExecution);
@@ -283,7 +285,7 @@ class StepListenerFactoryBeanTests {
 		factoryBean.setDelegate(delegate);
 		@SuppressWarnings("unchecked")
 		ItemWriteListener<String> listener = (ItemWriteListener<String>) factoryBean.getObject();
-		listener.afterWrite(Arrays.asList("foo", "bar"));
+		listener.afterWrite(Chunk.of("foo", "bar"));
 		assertTrue(delegate.isExecuted());
 	}
 
@@ -291,16 +293,16 @@ class StepListenerFactoryBeanTests {
 	void testRightSignatureAnnotation() {
 		AbstractTestComponent delegate = new AbstractTestComponent() {
 			@AfterWrite
-			public void aMethod(List<String> items) {
+			public void aMethod(Chunk<String> chunk) {
 				executed = true;
-				assertEquals("foo", items.get(0));
-				assertEquals("bar", items.get(1));
+				assertEquals("foo", chunk.getItems().get(0));
+				assertEquals("bar", chunk.getItems().get(1));
 			}
 		};
 		factoryBean.setDelegate(delegate);
 		@SuppressWarnings("unchecked")
 		ItemWriteListener<String> listener = (ItemWriteListener<String>) factoryBean.getObject();
-		listener.afterWrite(Arrays.asList("foo", "bar"));
+		listener.afterWrite(Chunk.of("foo", "bar"));
 		assertTrue(delegate.isExecuted());
 	}
 
@@ -330,7 +332,7 @@ class StepListenerFactoryBeanTests {
 		factoryBean.setMetaDataMap(metaDataMap);
 		@SuppressWarnings("unchecked")
 		ItemWriteListener<String> listener = (ItemWriteListener<String>) factoryBean.getObject();
-		listener.afterWrite(Arrays.asList("foo", "bar"));
+		listener.afterWrite(Chunk.of("foo", "bar"));
 		assertTrue(delegate.isExecuted());
 	}
 
@@ -338,19 +340,18 @@ class StepListenerFactoryBeanTests {
 	void testRightSignatureNamedMethod() {
 		AbstractTestComponent delegate = new AbstractTestComponent() {
 			@SuppressWarnings("unused")
-			public void aMethod(List<String> items) {
+			public void aMethod(Chunk<String> chunk) {
 				executed = true;
-				assertEquals("foo", items.get(0));
-				assertEquals("bar", items.get(1));
+				assertEquals("foo", chunk.getItems().get(0));
+				assertEquals("bar", chunk.getItems().get(1));
 			}
 		};
 		factoryBean.setDelegate(delegate);
 		Map<String, String> metaDataMap = new HashMap<>();
 		metaDataMap.put(AFTER_WRITE.getPropertyName(), "aMethod");
 		factoryBean.setMetaDataMap(metaDataMap);
-		@SuppressWarnings("unchecked")
 		ItemWriteListener<String> listener = (ItemWriteListener<String>) factoryBean.getObject();
-		listener.afterWrite(Arrays.asList("foo", "bar"));
+		listener.afterWrite(Chunk.of("foo", "bar"));
 		assertTrue(delegate.isExecuted());
 	}
 

spring-batch-core/src/test/java/org/springframework/batch/core/partition/ExampleItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2012 the original author or authors.
+ * Copyright 2008-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,8 @@ import java.util.List;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 
 /**
@@ -40,12 +42,12 @@ public class ExampleItemWriter implements ItemWriter<String> {
 	}
 
 	/**
-	 * @see ItemWriter#write(List)
+	 * @see ItemWriter#write(Chunk)
 	 */
 	@Override
-	public void write(List<? extends String> data) throws Exception {
+	public void write(Chunk<? extends String> data) throws Exception {
 		log.info(data);
-		items.addAll(data);
+		items.addAll(data.getItems());
 	}
 
 }

spring-batch-core/src/test/java/org/springframework/batch/core/repository/dao/OptimisticLockingFailureTests.java

@@ -36,6 +36,7 @@ import org.springframework.batch.core.launch.JobOperator;
 import org.springframework.batch.core.repository.JobRepository;
 import org.springframework.batch.core.scope.context.ChunkContext;
 import org.springframework.batch.core.step.tasklet.Tasklet;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.repeat.RepeatStatus;
 import org.springframework.context.ApplicationContext;
@@ -109,7 +110,7 @@ class OptimisticLockingFailureTests {
 	public static class Writer implements ItemWriter<String> {
 
 		@Override
-		public void write(List<? extends String> items) throws Exception {
+		public void write(Chunk<? extends String> items) throws Exception {
 			for (String item : items) {
 				System.out.println(item);
 			}

spring-batch-core/src/test/java/org/springframework/batch/core/step/builder/RegisterMultiListenerTests.java

@@ -38,6 +38,7 @@ import org.springframework.batch.core.configuration.annotation.JobBuilderFactory
 import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
 import org.springframework.batch.core.launch.JobLauncher;
 import org.springframework.batch.core.scope.context.ChunkContext;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemReader;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.item.NonTransientResourceException;
@@ -61,6 +62,7 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
  *
  * @author Tobias Flohre
  * @author Michael Minella
+ * @author Mahmoud Ben Hassine
  */
 class RegisterMultiListenerTests {
 
@@ -174,8 +176,8 @@ class RegisterMultiListenerTests {
 			return new ItemWriter<String>() {
 
 				@Override
-				public void write(List<? extends String> items) throws Exception {
-					if (items.contains("item2")) {
+				public void write(Chunk<? extends String> chunk) throws Exception {
+					if (chunk.getItems().contains("item2")) {
 						throw new MySkippableException();
 					}
 				}
@@ -267,16 +269,16 @@ class RegisterMultiListenerTests {
 		}
 
 		@Override
-		public void beforeWrite(List<? extends String> items) {
+		public void beforeWrite(Chunk<? extends String> items) {
 			callChecker.beforeWriteCalled++;
 		}
 
 		@Override
-		public void afterWrite(List<? extends String> items) {
+		public void afterWrite(Chunk<? extends String> items) {
 		}
 
 		@Override
-		public void onWriteError(Exception exception, List<? extends String> items) {
+		public void onWriteError(Exception exception, Chunk<? extends String> items) {
 		}
 
 		@Override

spring-batch-core/src/test/java/org/springframework/batch/core/step/item/AlmostStatefulRetryChunkTests.java

@@ -26,12 +26,15 @@ import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
 
+import org.springframework.batch.item.Chunk;
+
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  *
  */
 class AlmostStatefulRetryChunkTests {

spring-batch-core/src/test/java/org/springframework/batch/core/step/item/ChunkOrientedTaskletTests.java

@@ -27,9 +27,11 @@ import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.StepContribution;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.scope.context.ChunkContext;
+import org.springframework.batch.item.Chunk;
 
 /**
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  *
  */
 class ChunkOrientedTaskletTests {

spring-batch-core/src/test/java/org/springframework/batch/core/step/item/FaultTolerantChunkProcessorTests.java

@@ -36,6 +36,7 @@ import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.listener.ItemListenerSupport;
 import org.springframework.batch.core.step.skip.AlwaysSkipItemSkipPolicy;
 import org.springframework.batch.core.step.skip.LimitCheckingItemSkipPolicy;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemProcessor;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.item.support.PassThroughItemProcessor;
@@ -66,11 +67,11 @@ class FaultTolerantChunkProcessorTests {
 		batchRetryTemplate = new BatchRetryTemplate();
 		processor = new FaultTolerantChunkProcessor<>(new PassThroughItemProcessor<>(), new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> items) throws Exception {
-				if (items.contains("fail")) {
+			public void write(Chunk<? extends String> chunk) throws Exception {
+				if (chunk.getItems().contains("fail")) {
 					throw new RuntimeException("Planned failure!");
 				}
-				list.addAll(items);
+				list.addAll(chunk.getItems());
 			}
 		}, batchRetryTemplate);
 		batchRetryTemplate.setRetryPolicy(new NeverRetryPolicy());
@@ -193,8 +194,8 @@ class FaultTolerantChunkProcessorTests {
 		processor.setWriteSkipPolicy(new AlwaysSkipItemSkipPolicy());
 		processor.setItemWriter(new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> items) throws Exception {
-				if (items.contains("fail")) {
+			public void write(Chunk<? extends String> chunk) throws Exception {
+				if (chunk.getItems().contains("fail")) {
 					fail("Expected Error!");
 				}
 			}
@@ -210,8 +211,8 @@ class FaultTolerantChunkProcessorTests {
 		processor.setWriteSkipPolicy(new AlwaysSkipItemSkipPolicy());
 		processor.setItemWriter(new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> items) throws Exception {
-				if (items.contains("fail")) {
+			public void write(Chunk<? extends String> chunk) throws Exception {
+				if (chunk.getItems().contains("fail")) {
 					throw new RuntimeException("Expected Exception!");
 				}
 			}
@@ -232,8 +233,8 @@ class FaultTolerantChunkProcessorTests {
 		processor.setWriteSkipPolicy(new AlwaysSkipItemSkipPolicy());
 		processor.setItemWriter(new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> items) throws Exception {
-				if (items.contains("fail")) {
+			public void write(Chunk<? extends String> chunk) throws Exception {
+				if (chunk.getItems().contains("fail")) {
 					throw new RuntimeException("Expected Exception!");
 				}
 			}
@@ -276,8 +277,8 @@ class FaultTolerantChunkProcessorTests {
 		Chunk<String> chunk = new Chunk<>(Arrays.asList("foo", "fail", "bar"));
 		processor.setListeners(Arrays.asList(new ItemListenerSupport<String, String>() {
 			@Override
-			public void afterWrite(List<? extends String> item) {
-				after.addAll(item);
+			public void afterWrite(Chunk<? extends String> chunk) {
+				after.addAll(chunk.getItems());
 			}
 		}));
 		processor.setWriteSkipPolicy(new AlwaysSkipItemSkipPolicy());
@@ -301,18 +302,18 @@ class FaultTolerantChunkProcessorTests {
 		Chunk<String> chunk = new Chunk<>(Arrays.asList("foo", "bar"));
 		processor = new FaultTolerantChunkProcessor<>(new PassThroughItemProcessor<>(), new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> items) throws Exception {
+			public void write(Chunk<? extends String> chunk) throws Exception {
 				// Fail if there is more than one item
-				if (items.size() > 1) {
+				if (chunk.size() > 1) {
 					throw new RuntimeException("Planned failure!");
 				}
-				list.addAll(items);
+				list.addAll(chunk.getItems());
 			}
 		}, batchRetryTemplate);
 		processor.setListeners(Arrays.asList(new ItemListenerSupport<String, String>() {
 			@Override
-			public void afterWrite(List<? extends String> item) {
-				after.addAll(item);
+			public void afterWrite(Chunk<? extends String> chunk) {
+				after.addAll(chunk.getItems());
 			}
 		}));
 		processor.setWriteSkipPolicy(new AlwaysSkipItemSkipPolicy());
@@ -330,8 +331,8 @@ class FaultTolerantChunkProcessorTests {
 		Chunk<String> chunk = new Chunk<>(Arrays.asList("foo", "fail"));
 		processor.setListeners(Arrays.asList(new ItemListenerSupport<String, String>() {
 			@Override
-			public void onWriteError(Exception e, List<? extends String> item) {
-				writeError.addAll(item);
+			public void onWriteError(Exception e, Chunk<? extends String> chunk) {
+				writeError.addAll(chunk.getItems());
 			}
 		}));
 		processor.setWriteSkipPolicy(new AlwaysSkipItemSkipPolicy());
@@ -348,15 +349,15 @@ class FaultTolerantChunkProcessorTests {
 		Chunk<String> chunk = new Chunk<>(Arrays.asList("foo", "bar"));
 		processor = new FaultTolerantChunkProcessor<>(new PassThroughItemProcessor<>(), new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> items) throws Exception {
+			public void write(Chunk<? extends String> items) throws Exception {
 				// Always fail in writer
 				throw new RuntimeException("Planned failure!");
 			}
 		}, batchRetryTemplate);
 		processor.setListeners(Arrays.asList(new ItemListenerSupport<String, String>() {
 			@Override
-			public void onWriteError(Exception e, List<? extends String> item) {
-				writeError.addAll(item);
+			public void onWriteError(Exception e, Chunk<? extends String> chunk) {
+				writeError.addAll(chunk.getItems());
 			}
 		}));
 		processor.setWriteSkipPolicy(new AlwaysSkipItemSkipPolicy());
@@ -376,8 +377,8 @@ class FaultTolerantChunkProcessorTests {
 		processor.setWriteSkipPolicy(new AlwaysSkipItemSkipPolicy());
 		processor.setItemWriter(new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> items) throws Exception {
-				if (items.contains("fail")) {
+			public void write(Chunk<? extends String> chunk) throws Exception {
+				if (chunk.getItems().contains("fail")) {
 					throw new IllegalArgumentException("Expected Exception!");
 				}
 			}
@@ -408,8 +409,8 @@ class FaultTolerantChunkProcessorTests {
 		processor.setWriteSkipPolicy(new AlwaysSkipItemSkipPolicy());
 		processor.setItemWriter(new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> items) throws Exception {
-				if (items.contains("fail")) {
+			public void write(Chunk<? extends String> chunk) throws Exception {
+				if (chunk.getItems().contains("fail")) {
 					throw new IllegalArgumentException("Expected Exception!");
 				}
 			}
@@ -445,11 +446,11 @@ class FaultTolerantChunkProcessorTests {
 				Collections.<Class<? extends Throwable>, Boolean>singletonMap(IllegalArgumentException.class, true)));
 		processor.setItemWriter(new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> items) throws Exception {
-				if (items.contains("fail")) {
+			public void write(Chunk<? extends String> chunk) throws Exception {
+				if (chunk.getItems().contains("fail")) {
 					throw new IllegalArgumentException("Expected Exception!");
 				}
-				if (items.contains("2")) {
+				if (chunk.getItems().contains("2")) {
 					throw new RuntimeException("Expected Non-Skippable Exception!");
 				}
 			}

spring-batch-core/src/test/java/org/springframework/batch/core/step/item/FaultTolerantChunkProviderTests.java

@@ -28,6 +28,7 @@ import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.StepContribution;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.step.skip.LimitCheckingItemSkipPolicy;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemReader;
 import org.springframework.batch.item.ParseException;
 import org.springframework.batch.item.UnexpectedInputException;

spring-batch-core/src/test/java/org/springframework/batch/core/step/item/FaultTolerantStepFactoryBeanNonBufferingTests.java

@@ -35,6 +35,7 @@ import org.springframework.batch.core.Step;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.step.JobRepositorySupport;
 import org.springframework.batch.core.step.factory.FaultTolerantStepFactoryBean;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.item.support.ListItemReader;
 import org.springframework.batch.support.transaction.ResourcelessTransactionManager;
@@ -141,7 +142,7 @@ class FaultTolerantStepFactoryBeanNonBufferingTests {
 		}
 
 		@Override
-		public void write(List<? extends String> items) throws Exception {
+		public void write(Chunk<? extends String> items) throws Exception {
 			logger.debug("Writing: " + items);
 			for (String item : items) {
 				if (failures.contains(item)) {

spring-batch-core/src/test/java/org/springframework/batch/core/step/item/FaultTolerantStepFactoryBeanRetryTests.java

@@ -41,6 +41,7 @@ import org.springframework.batch.core.repository.JobRepository;
 import org.springframework.batch.core.repository.support.JobRepositoryFactoryBean;
 import org.springframework.batch.core.step.AbstractStep;
 import org.springframework.batch.core.step.factory.FaultTolerantStepFactoryBean;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.ItemProcessor;
 import org.springframework.batch.item.ItemReader;
@@ -91,8 +92,8 @@ class FaultTolerantStepFactoryBeanRetryTests {
 
 	private ItemWriter<String> writer = new ItemWriter<String>() {
 		@Override
-		public void write(List<? extends String> data) throws Exception {
-			processed.addAll(data);
+		public void write(Chunk<? extends String> data) throws Exception {
+			processed.addAll(data.getItems());
 		}
 	};
 
@@ -152,7 +153,7 @@ class FaultTolerantStepFactoryBeanRetryTests {
 		factory.setTransactionManager(new ResourcelessTransactionManager());
 		ItemWriter<Integer> failingWriter = new ItemWriter<Integer>() {
 			@Override
-			public void write(List<? extends Integer> data) throws Exception {
+			public void write(Chunk<? extends Integer> data) throws Exception {
 				int count = 0;
 				for (Integer item : data) {
 					if (count++ == 2) {
@@ -202,7 +203,7 @@ class FaultTolerantStepFactoryBeanRetryTests {
 		final List<String> ITEM_LIST = Arrays.asList("a", "b", "c");
 		ItemWriter<String> failingWriter = new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> data) throws Exception {
+			public void write(Chunk<? extends String> data) throws Exception {
 				int count = 0;
 				for (String item : data) {
 					if (count++ == 2) {
@@ -248,7 +249,7 @@ class FaultTolerantStepFactoryBeanRetryTests {
 	void testNoItemsReprocessedWhenErrorInWriterAndProcessorNotTransactional() throws Exception {
 		ItemWriter<String> failingWriter = new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> data) throws Exception {
+			public void write(Chunk<? extends String> data) throws Exception {
 				int count = 0;
 				for (String item : data) {
 					if (count++ == 2) {
@@ -358,11 +359,11 @@ class FaultTolerantStepFactoryBeanRetryTests {
 		factory.setStreams(new ItemStream[] { reader });
 		factory.setItemWriter(new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> items) throws Exception {
-				if (fail && items.contains("e")) {
+			public void write(Chunk<? extends String> chunk) throws Exception {
+				if (fail && chunk.getItems().contains("e")) {
 					throw new RuntimeException("Planned failure");
 				}
-				processed.addAll(items);
+				processed.addAll(chunk.getItems());
 			}
 		});
 		factory.setRetryLimit(0);
@@ -445,11 +446,11 @@ class FaultTolerantStepFactoryBeanRetryTests {
 
 		ItemWriter<String> itemWriter = new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> item) throws Exception {
-				logger.debug("Write Called! Item: [" + item + "]");
-				processed.addAll(item);
-				written.addAll(item);
-				if (item.contains("b") || item.contains("d")) {
+			public void write(Chunk<? extends String> chunk) throws Exception {
+				logger.debug("Write Called! Item: [" + chunk.getItems() + "]");
+				processed.addAll(chunk.getItems());
+				written.addAll(chunk.getItems());
+				if (chunk.getItems().contains("b") || chunk.getItems().contains("d")) {
 					throw new RuntimeException("Write error - planned but recoverable.");
 				}
 			}
@@ -503,11 +504,11 @@ class FaultTolerantStepFactoryBeanRetryTests {
 
 		ItemWriter<String> itemWriter = new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> item) throws Exception {
-				logger.debug("Write Called! Item: [" + item + "]");
-				processed.addAll(item);
-				written.addAll(item);
-				if (item.contains("b") || item.contains("d")) {
+			public void write(Chunk<? extends String> chunk) throws Exception {
+				logger.debug("Write Called! Item: [" + chunk + "]");
+				processed.addAll(chunk.getItems());
+				written.addAll(chunk.getItems());
+				if (chunk.getItems().contains("b") || chunk.getItems().contains("d")) {
 					throw new RuntimeException("Write error - planned but recoverable.");
 				}
 			}
@@ -556,10 +557,10 @@ class FaultTolerantStepFactoryBeanRetryTests {
 		};
 		ItemWriter<String> itemWriter = new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> item) throws Exception {
-				processed.addAll(item);
-				written.addAll(item);
-				logger.debug("Write Called! Item: [" + item + "]");
+			public void write(Chunk<? extends String> chunk) throws Exception {
+				processed.addAll(chunk.getItems());
+				written.addAll(chunk.getItems());
+				logger.debug("Write Called! Item: [" + chunk.getItems() + "]");
 				throw new RuntimeException("Write error - planned but retryable.");
 			}
 		};
@@ -608,10 +609,10 @@ class FaultTolerantStepFactoryBeanRetryTests {
 		};
 		ItemWriter<String> itemWriter = new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> item) throws Exception {
-				processed.addAll(item);
-				written.addAll(item);
-				logger.debug("Write Called! Item: [" + item + "]");
+			public void write(Chunk<? extends String> chunk) throws Exception {
+				processed.addAll(chunk.getItems());
+				written.addAll(chunk.getItems());
+				logger.debug("Write Called! Item: [" + chunk.getItems() + "]");
 				throw new RuntimeException("Write error - planned but not skippable.");
 			}
 		};
@@ -655,10 +656,10 @@ class FaultTolerantStepFactoryBeanRetryTests {
 		};
 		ItemWriter<String> itemWriter = new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> item) throws Exception {
-				processed.addAll(item);
-				written.addAll(item);
-				logger.debug("Write Called! Item: [" + item + "]");
+			public void write(Chunk<? extends String> chunk) throws Exception {
+				processed.addAll(chunk.getItems());
+				written.addAll(chunk.getItems());
+				logger.debug("Write Called! Item: [" + chunk.getItems() + "]");
 				throw new RuntimeException("Write error - planned but retryable.");
 			}
 		};
@@ -707,9 +708,9 @@ class FaultTolerantStepFactoryBeanRetryTests {
 		};
 		ItemWriter<String> itemWriter = new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> item) throws Exception {
-				processed.addAll(item);
-				logger.debug("Write Called! Item: [" + item + "]");
+			public void write(Chunk<? extends String> chunk) throws Exception {
+				processed.addAll(chunk.getItems());
+				logger.debug("Write Called! Item: [" + chunk.getItems() + "]");
 				throw new RuntimeException("Write error - planned but retryable.");
 			}
 		};

spring-batch-core/src/test/java/org/springframework/batch/core/step/item/FaultTolerantStepFactoryBeanTests.java

@@ -49,6 +49,7 @@ import org.springframework.batch.core.step.factory.FaultTolerantStepFactoryBean;
 import org.springframework.batch.core.step.skip.LimitCheckingItemSkipPolicy;
 import org.springframework.batch.core.step.skip.SkipLimitExceededException;
 import org.springframework.batch.core.step.skip.SkipPolicy;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.ItemReader;
 import org.springframework.batch.item.ItemStream;
@@ -451,7 +452,7 @@ public class FaultTolerantStepFactoryBeanTests {
 		factory.setSkippableExceptionClasses(map);
 		factory.setItemWriter(new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> items) {
+			public void write(Chunk<? extends String> items) {
 				throw new FatalRuntimeException("Ouch!");
 			}
 		});
@@ -766,8 +767,8 @@ public class FaultTolerantStepFactoryBeanTests {
 				ItemProcessListener<String, String>, SkipListener<String, String>, ChunkListener {
 
 			@Override
-			public void write(List<? extends String> items) throws Exception {
-				if (items.contains("4")) {
+			public void write(Chunk<? extends String> chunk) throws Exception {
+				if (chunk.getItems().contains("4")) {
 					throw new SkippableException("skippable");
 				}
 			}
@@ -786,16 +787,16 @@ public class FaultTolerantStepFactoryBeanTests {
 			}
 
 			@Override
-			public void afterWrite(List<? extends String> items) {
+			public void afterWrite(Chunk<? extends String> items) {
 				listenerCalls.add(2);
 			}
 
 			@Override
-			public void beforeWrite(List<? extends String> items) {
+			public void beforeWrite(Chunk<? extends String> items) {
 			}
 
 			@Override
-			public void onWriteError(Exception exception, List<? extends String> items) {
+			public void onWriteError(Exception exception, Chunk<? extends String> items) {
 			}
 
 			@Override

spring-batch-core/src/test/java/org/springframework/batch/core/step/item/ScriptItemProcessorTests.java

@@ -19,6 +19,7 @@ import org.junit.jupiter.api.Test;
 import org.springframework.batch.core.Job;
 import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.launch.JobLauncher;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
@@ -33,6 +34,7 @@ import java.util.List;
  * </p>
  *
  * @author Chris Schaefer
+ * @author Mahmoud Ben Hassine
  * @since 3.1
  */
 @SpringJUnitConfig
@@ -52,12 +54,12 @@ class ScriptItemProcessorTests {
 	public static class TestItemWriter implements ItemWriter<String> {
 
 		@Override
-		public void write(List<? extends String> items) throws Exception {
-			Assert.notNull(items, "Items cannot be null");
-			Assert.isTrue(!items.isEmpty(), "Items cannot be empty");
-			Assert.isTrue(items.size() == 1, "Items should only contain one entry");
+		public void write(Chunk<? extends String> chunk) throws Exception {
+			Assert.notNull(chunk.getItems(), "Items cannot be null");
+			Assert.isTrue(!chunk.getItems().isEmpty(), "Items cannot be empty");
+			Assert.isTrue(chunk.getItems().size() == 1, "Items should only contain one entry");
 
-			String item = items.get(0);
+			String item = chunk.getItems().get(0);
 			Assert.isTrue("BLAH".equals(item), "Transformed item to write should have been: BLAH but got: " + item);
 		}
 

spring-batch-core/src/test/java/org/springframework/batch/core/step/item/SimpleChunkProcessorTests.java

@@ -28,6 +28,7 @@ import org.springframework.batch.core.JobInstance;
 import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.StepContribution;
 import org.springframework.batch.core.StepExecution;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemProcessor;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.lang.Nullable;
@@ -46,11 +47,11 @@ class SimpleChunkProcessorTests {
 				}
 			}, new ItemWriter<String>() {
 				@Override
-				public void write(List<? extends String> items) throws Exception {
-					if (items.contains("fail")) {
+				public void write(Chunk<? extends String> chunk) throws Exception {
+					if (chunk.getItems().contains("fail")) {
 						throw new RuntimeException("Planned failure!");
 					}
-					list.addAll(items);
+					list.addAll(chunk.getItems());
 				}
 			});
 

spring-batch-core/src/test/java/org/springframework/batch/core/step/item/SimpleChunkProviderTests.java

@@ -26,6 +26,7 @@ import org.springframework.batch.core.JobInstance;
 import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.StepContribution;
 import org.springframework.batch.core.StepExecution;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.support.ListItemReader;
 import org.springframework.batch.repeat.support.RepeatTemplate;
 

spring-batch-core/src/test/java/org/springframework/batch/core/step/item/SimpleStepFactoryBeanTests.java

@@ -46,6 +46,7 @@ import org.springframework.batch.core.repository.support.JobRepositoryFactoryBea
 import org.springframework.batch.core.scope.context.ChunkContext;
 import org.springframework.batch.core.step.AbstractStep;
 import org.springframework.batch.core.step.factory.SimpleStepFactoryBean;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemProcessor;
 import org.springframework.batch.item.ItemReader;
 import org.springframework.batch.item.ItemWriter;
@@ -72,8 +73,8 @@ class SimpleStepFactoryBeanTests {
 
 	private final ItemWriter<String> writer = new ItemWriter<String>() {
 		@Override
-		public void write(List<? extends String> data) throws Exception {
-			written.addAll(data);
+		public void write(Chunk<? extends String> data) throws Exception {
+			written.addAll(data.getItems());
 		}
 	};
 
@@ -174,7 +175,7 @@ class SimpleStepFactoryBeanTests {
 
 		factory.setItemWriter(new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> data) throws Exception {
+			public void write(Chunk<? extends String> data) throws Exception {
 				throw new RuntimeException("Error!");
 			}
 		});
@@ -185,7 +186,7 @@ class SimpleStepFactoryBeanTests {
 			}
 
 			@Override
-			public void onWriteError(Exception ex, List<? extends String> item) {
+			public void onWriteError(Exception ex, Chunk<? extends String> item) {
 				listened.add(ex);
 			}
 		} });
@@ -212,7 +213,7 @@ class SimpleStepFactoryBeanTests {
 		factory.setBeanName("exceptionStep");
 		factory.setItemWriter(new ItemWriter<String>() {
 			@Override
-			public void write(List<? extends String> data) throws Exception {
+			public void write(Chunk<? extends String> data) throws Exception {
 				throw new RuntimeException("Foo");
 			}
 		});
@@ -237,7 +238,7 @@ class SimpleStepFactoryBeanTests {
 			int count = 0;
 
 			@Override
-			public void write(List<? extends String> data) throws Exception {
+			public void write(Chunk<? extends String> data) throws Exception {
 				if (count++ == 0) {
 					throw new RuntimeException("Foo");
 				}
@@ -264,8 +265,8 @@ class SimpleStepFactoryBeanTests {
 			String trail = "";
 
 			@Override
-			public void beforeWrite(List<? extends Object> items) {
-				if (items.contains("error")) {
+			public void beforeWrite(Chunk<? extends Object> chunk) {
+				if (chunk.getItems().contains("error")) {
 					throw new RuntimeException("rollback the last chunk");
 				}
 
@@ -273,7 +274,7 @@ class SimpleStepFactoryBeanTests {
 			}
 
 			@Override
-			public void afterWrite(List<? extends Object> items) {
+			public void afterWrite(Chunk<? extends Object> items) {
 				trail = trail + "3";
 			}
 
@@ -379,7 +380,7 @@ class SimpleStepFactoryBeanTests {
 				ItemWriteListener<String>, ItemProcessListener<String, String>, ChunkListener {
 
 			@Override
-			public void write(List<? extends String> items) throws Exception {
+			public void write(Chunk<? extends String> items) throws Exception {
 			}
 
 			@Nullable
@@ -402,16 +403,16 @@ class SimpleStepFactoryBeanTests {
 			}
 
 			@Override
-			public void afterWrite(List<? extends String> items) {
+			public void afterWrite(Chunk<? extends String> items) {
 				listenerCalls.add("write");
 			}
 
 			@Override
-			public void beforeWrite(List<? extends String> items) {
+			public void beforeWrite(Chunk<? extends String> items) {
 			}
 
 			@Override
-			public void onWriteError(Exception exception, List<? extends String> items) {
+			public void onWriteError(Exception exception, Chunk<? extends String> items) {
 			}
 
 			@Override
@@ -470,20 +471,20 @@ class SimpleStepFactoryBeanTests {
 		class TestItemListenerWriter implements ItemWriter<String>, ItemWriteListener<String> {
 
 			@Override
-			public void write(List<? extends String> items) throws Exception {
+			public void write(Chunk<? extends String> items) throws Exception {
 			}
 
 			@Override
-			public void afterWrite(List<? extends String> items) {
+			public void afterWrite(Chunk<? extends String> items) {
 				listenerCalls.add("write");
 			}
 
 			@Override
-			public void beforeWrite(List<? extends String> items) {
+			public void beforeWrite(Chunk<? extends String> items) {
 			}
 
 			@Override
-			public void onWriteError(Exception exception, List<? extends String> items) {
+			public void onWriteError(Exception exception, Chunk<? extends String> items) {
 			}
 
 		}

spring-batch-core/src/test/java/org/springframework/batch/core/step/item/SkipWrapperTests.java

@@ -21,8 +21,11 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import org.junit.jupiter.api.Test;
 
+import org.springframework.batch.item.SkipWrapper;
+
 /**
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  *
  */
 class SkipWrapperTests {
@@ -41,7 +44,7 @@ class SkipWrapperTests {
 
 	/**
 	 * Test method for
-	 * {@link org.springframework.batch.core.step.item.SkipWrapper#SkipWrapper(java.lang.Object, java.lang.Throwable)}.
+	 * {@link SkipWrapper#SkipWrapper(java.lang.Object, java.lang.Throwable)}.
 	 */
 	@Test
 	void testItemWrapperTException() {
@@ -51,8 +54,7 @@ class SkipWrapperTests {
 	}
 
 	/**
-	 * Test method for
-	 * {@link org.springframework.batch.core.step.item.SkipWrapper#toString()}.
+	 * Test method for {@link SkipWrapper#toString()}.
 	 */
 	@Test
 	void testToString() {

spring-batch-core/src/test/java/org/springframework/batch/core/step/item/SkipWriterStub.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2013 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,11 +18,13 @@ package org.springframework.batch.core.step.item;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.support.transaction.TransactionAwareProxyFactory;
 
 /**
  * @author Dan Garrette
+ * @author Mahmoud Ben Hassine
  * @since 2.0.1
  */
 public class SkipWriterStub<T> extends AbstractExceptionThrowingItemHandlerStub<T> implements ItemWriter<T> {
@@ -49,7 +51,7 @@ public class SkipWriterStub<T> extends AbstractExceptionThrowingItemHandlerStub<
 	}
 
 	@Override
-	public void write(List<? extends T> items) throws Exception {
+	public void write(Chunk<? extends T> items) throws Exception {
 		logger.debug("Writing: " + items);
 		for (T item : items) {
 			written.add(item);

spring-batch-core/src/test/java/org/springframework/batch/core/step/skip/ReprocessExceptionTests.java

@@ -21,6 +21,7 @@ import org.springframework.batch.core.Job;
 import org.springframework.batch.core.JobExecution;
 import org.springframework.batch.core.JobParametersBuilder;
 import org.springframework.batch.core.launch.JobLauncher;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemProcessor;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -33,6 +34,7 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 
 /**
  * @author mminella
+ * @author Mahmoud Ben Hassine
  */
 @SpringJUnitConfig
 public class ReprocessExceptionTests {
@@ -77,7 +79,7 @@ public class ReprocessExceptionTests {
 	public static class PersonItemWriter implements ItemWriter<Person> {
 
 		@Override
-		public void write(List<? extends Person> persons) throws Exception {
+		public void write(Chunk<? extends Person> persons) throws Exception {
 			for (Person person : persons) {
 				System.out.println(person.getFirstName() + " " + person.getLastName());
 				if (person.getFirstName().equals("JANE")) {

spring-batch-core/src/test/java/org/springframework/batch/core/step/tasklet/AsyncChunkOrientedStepIntegrationTests.java

@@ -34,6 +34,7 @@ import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.job.JobSupport;
 import org.springframework.batch.core.repository.JobRepository;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemReader;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.item.support.ListItemReader;
@@ -53,6 +54,7 @@ import static org.junit.jupiter.api.Assertions.assertNotSame;
 
 /**
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  *
  */
 @SpringJUnitConfig(locations = "/org/springframework/batch/core/repository/dao/sql-dao-test.xml")
@@ -125,8 +127,8 @@ class AsyncChunkOrientedStepIntegrationTests {
 				getReader(new String[] { "a", "b", "c", "a", "b", "c", "a", "b", "c", "a", "b", "c" }),
 				new ItemWriter<String>() {
 					@Override
-					public void write(List<? extends String> data) throws Exception {
-						written.addAll(data);
+					public void write(Chunk<? extends String> data) throws Exception {
+						written.addAll(data.getItems());
 					}
 				}, chunkOperations));
 

spring-batch-core/src/test/java/org/springframework/batch/core/step/tasklet/AsyncTaskletStepTests.java

@@ -33,6 +33,7 @@ import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.repository.JobRepository;
 import org.springframework.batch.core.step.JobRepositorySupport;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.ItemProcessor;
 import org.springframework.batch.item.ItemStreamSupport;
@@ -59,11 +60,11 @@ class AsyncTaskletStepTests {
 
 	ItemWriter<String> itemWriter = new ItemWriter<String>() {
 		@Override
-		public void write(List<? extends String> data) throws Exception {
+		public void write(Chunk<? extends String> data) throws Exception {
 			// Thread.sleep(100L);
 			logger.info("Items: " + data);
-			processed.addAll(data);
-			if (data.contains("fail")) {
+			processed.addAll(data.getItems());
+			if (data.getItems().contains("fail")) {
 				throw new RuntimeException("Planned");
 			}
 		}

spring-batch-core/src/test/java/org/springframework/batch/core/step/tasklet/StepExecutorInterruptionTests.java

@@ -37,6 +37,7 @@ import org.springframework.batch.core.repository.JobInstanceAlreadyCompleteExcep
 import org.springframework.batch.core.repository.JobRepository;
 import org.springframework.batch.core.repository.JobRestartException;
 import org.springframework.batch.core.repository.support.JobRepositoryFactoryBean;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemReader;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.repeat.policy.SimpleCompletionPolicy;
@@ -88,7 +89,7 @@ class StepExecutorInterruptionTests {
 		step.setTransactionManager(this.transactionManager);
 		itemWriter = new ItemWriter<Object>() {
 			@Override
-			public void write(List<? extends Object> item) throws Exception {
+			public void write(Chunk<? extends Object> item) throws Exception {
 			}
 		};
 		stepExecution = new StepExecution(step.getName(), jobExecution);

spring-batch-core/src/test/java/org/springframework/batch/core/step/tasklet/TaskletStepTests.java

@@ -45,6 +45,7 @@ import org.springframework.batch.core.repository.support.JobRepositoryFactoryBea
 import org.springframework.batch.core.scope.context.ChunkContext;
 import org.springframework.batch.core.step.JobRepositorySupport;
 import org.springframework.batch.core.step.StepInterruptionPolicy;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.ItemReader;
 import org.springframework.batch.item.ItemStream;
@@ -75,8 +76,8 @@ class TaskletStepTests {
 
 	ItemWriter<String> itemWriter = new ItemWriter<String>() {
 		@Override
-		public void write(List<? extends String> data) throws Exception {
-			processed.addAll(data);
+		public void write(Chunk<? extends String> data) throws Exception {
+			processed.addAll(data.getItems());
 		}
 	};
 

spring-batch-core/src/test/java/org/springframework/batch/core/test/football/internal/JdbcGameDao.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2007 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@ package org.springframework.batch.core.test.football.internal;
 import java.util.List;
 
 import org.springframework.batch.core.test.football.domain.Game;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
 import org.springframework.jdbc.core.namedparam.SqlParameterSource;
@@ -38,7 +39,7 @@ public class JdbcGameDao extends JdbcDaoSupport implements ItemWriter<Game> {
 	}
 
 	@Override
-	public void write(List<? extends Game> games) {
+	public void write(Chunk<? extends Game> games) {
 
 		for (Game game : games) {
 

spring-batch-core/src/test/java/org/springframework/batch/core/test/football/internal/JdbcPlayerSummaryDao.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2007 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@ package org.springframework.batch.core.test.football.internal;
 import java.util.List;
 
 import org.springframework.batch.core.test.football.domain.PlayerSummary;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
 import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
@@ -35,7 +36,7 @@ public class JdbcPlayerSummaryDao implements ItemWriter<PlayerSummary> {
 	private NamedParameterJdbcTemplate namedParameterJdbcTemplate;
 
 	@Override
-	public void write(List<? extends PlayerSummary> summaries) {
+	public void write(Chunk<? extends PlayerSummary> summaries) {
 
 		for (PlayerSummary summary : summaries) {
 

spring-batch-core/src/test/java/org/springframework/batch/core/test/football/internal/PlayerItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2007 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,7 @@ import java.util.List;
 
 import org.springframework.batch.core.test.football.domain.Player;
 import org.springframework.batch.core.test.football.domain.PlayerDao;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 
 public class PlayerItemWriter implements ItemWriter<Player> {
@@ -27,7 +28,7 @@ public class PlayerItemWriter implements ItemWriter<Player> {
 	private PlayerDao playerDao;
 
 	@Override
-	public void write(List<? extends Player> players) throws Exception {
+	public void write(Chunk<? extends Player> players) throws Exception {
 		for (Player player : players) {
 			playerDao.savePlayer(player);
 		}

spring-batch-core/src/test/java/org/springframework/batch/core/test/step/FaultTolerantStepFactoryBeanIntegrationTests.java

@@ -39,6 +39,7 @@ import org.springframework.batch.core.Step;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.repository.JobRepository;
 import org.springframework.batch.core.step.factory.FaultTolerantStepFactoryBean;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemProcessor;
 import org.springframework.batch.item.ItemReader;
 import org.springframework.batch.item.ItemWriter;
@@ -111,7 +112,7 @@ class FaultTolerantStepFactoryBeanIntegrationTests {
 
 		JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);
 
-		writer.write(Arrays.asList("foo", "bar"));
+		writer.write(Chunk.of("foo", "bar"));
 		processor.process("spam");
 		assertEquals(3, JdbcTestUtils.countRowsInTable(jdbcTemplate, "ERROR_LOG"));
 
@@ -228,7 +229,7 @@ class FaultTolerantStepFactoryBeanIntegrationTests {
 		}
 
 		@Override
-		public void write(List<? extends String> items) throws Exception {
+		public void write(Chunk<? extends String> items) throws Exception {
 			for (String item : items) {
 				written.add(item);
 				jdbcTemplate.update("INSERT INTO ERROR_LOG (MESSAGE, STEP_NAME) VALUES (?, ?)", item, "written");

spring-batch-core/src/test/java/org/springframework/batch/core/test/step/FaultTolerantStepFactoryBeanRollbackIntegrationTests.java

@@ -39,6 +39,7 @@ import org.springframework.batch.core.Step;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.repository.JobRepository;
 import org.springframework.batch.core.step.factory.FaultTolerantStepFactoryBean;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemProcessor;
 import org.springframework.batch.item.ItemReader;
 import org.springframework.batch.item.ItemWriter;
@@ -108,7 +109,7 @@ class FaultTolerantStepFactoryBeanRollbackIntegrationTests {
 
 		JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);
 
-		writer.write(Arrays.asList("foo", "bar"));
+		writer.write(Chunk.of("foo", "bar"));
 		processor.process("spam");
 		assertEquals(3, JdbcTestUtils.countRowsInTable(jdbcTemplate, "ERROR_LOG"));
 
@@ -253,7 +254,7 @@ class FaultTolerantStepFactoryBeanRollbackIntegrationTests {
 		}
 
 		@Override
-		public void write(List<? extends String> items) throws Exception {
+		public void write(Chunk<? extends String> items) throws Exception {
 			for (String item : items) {
 				written.add(item);
 				jdbcTemplate.update("INSERT INTO ERROR_LOG (MESSAGE, STEP_NAME) VALUES (?, ?)", item, "written");

spring-batch-core/src/test/java/org/springframework/batch/core/test/step/FaultTolerantStepIntegrationTests.java

@@ -35,6 +35,7 @@ import org.springframework.batch.core.step.builder.FaultTolerantStepBuilder;
 import org.springframework.batch.core.step.skip.AlwaysSkipItemSkipPolicy;
 import org.springframework.batch.core.step.skip.SkipLimitExceededException;
 import org.springframework.batch.core.step.skip.SkipPolicy;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemProcessor;
 import org.springframework.batch.item.ItemReader;
 import org.springframework.batch.item.ItemWriter;
@@ -71,7 +72,7 @@ class FaultTolerantStepIntegrationTests {
 	void setUp() {
 		ItemReader<Integer> itemReader = new ListItemReader<>(createItems());
 		ItemWriter<Integer> itemWriter = chunk -> {
-			if (chunk.contains(1)) {
+			if (chunk.getItems().contains(1)) {
 				throw new IllegalArgumentException();
 			}
 		};
@@ -169,7 +170,7 @@ class FaultTolerantStepIntegrationTests {
 			private int cpt;
 
 			@Override
-			public void write(List<? extends Integer> items) throws Exception {
+			public void write(Chunk<? extends Integer> items) throws Exception {
 				cpt++;
 				if (cpt == 1) {
 					throw new Exception("Error during write");
@@ -210,8 +211,8 @@ class FaultTolerantStepIntegrationTests {
 
 		ItemWriter<Integer> itemWriter = new ItemWriter<Integer>() {
 			@Override
-			public void write(List<? extends Integer> items) throws Exception {
-				if (items.contains(3)) {
+			public void write(Chunk<? extends Integer> chunk) throws Exception {
+				if (chunk.getItems().contains(3)) {
 					throw new Exception("Error during write");
 				}
 			}

spring-batch-core/src/test/java/org/springframework/batch/core/test/timeout/LoggingItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 the original author or authors.
+ * Copyright 2014-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,8 @@ import java.util.List;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 
 public class LoggingItemWriter<T> implements ItemWriter<T> {
@@ -26,7 +28,7 @@ public class LoggingItemWriter<T> implements ItemWriter<T> {
 	protected Log logger = LogFactory.getLog(LoggingItemWriter.class);
 
 	@Override
-	public void write(List<? extends T> items) throws Exception {
+	public void write(Chunk<? extends T> items) throws Exception {
 		logger.info(items);
 	}
 

spring-batch-docs/src/main/asciidoc/common-patterns.adoc

@@ -277,7 +277,7 @@ public class TradeItemWriter implements ItemWriter<Trade>,
 
     private BigDecimal totalAmount = BigDecimal.ZERO;
 
-    public void write(List<? extends Trade> items) throws Exception {
+    public void write(Chunk<? extends Trade> items) throws Exception {
         BigDecimal chunkTotal = BigDecimal.ZERO;
         for (Trade trade : items) {
             chunkTotal = chunkTotal.add(trade.getAmount());
@@ -665,7 +665,7 @@ then it is not persisted during `Step` execution. If the `Step` fails, that data
 public class SavingItemWriter implements ItemWriter<Object> {
     private StepExecution stepExecution;
 
-    public void write(List<? extends Object> items) throws Exception {
+    public void write(Chunk<? extends Object> items) throws Exception {
         // ...
 
         ExecutionContext stepContext = this.stepExecution.getExecutionContext();
@@ -759,7 +759,7 @@ in the following example:
 public class RetrievingItemWriter implements ItemWriter<Object> {
     private Object someObject;
 
-    public void write(List<? extends Object> items) throws Exception {
+    public void write(Chunk<? extends Object> items) throws Exception {
         // ...
     }
 

spring-batch-docs/src/main/asciidoc/processor.adoc

@@ -25,7 +25,7 @@ public class CompositeItemWriter<T> implements ItemWriter<T> {
         this.itemWriter = itemWriter;
     }
 
-    public void write(List<? extends T> items) throws Exception {
+    public void write(Chunk<? extends T> items) throws Exception {
         //Add business logic here
        itemWriter.write(items);
     }
@@ -77,7 +77,7 @@ public class FooProcessor implements ItemProcessor<Foo, Bar> {
 }
 
 public class BarWriter implements ItemWriter<Bar> {
-    public void write(List<? extends Bar> bars) throws Exception {
+    public void write(Chunk<? extends Bar> bars) throws Exception {
         //write bars
     }
 }
@@ -162,7 +162,7 @@ public class BarProcessor implements ItemProcessor<Bar, Foobar> {
 }
 
 public class FoobarWriter implements ItemWriter<Foobar>{
-    public void write(List<? extends Foobar> items) throws Exception {
+    public void write(Chunk<? extends Foobar> items) throws Exception {
         //write items
     }
 }

spring-batch-docs/src/main/asciidoc/readersAndWriters.adoc

@@ -78,7 +78,7 @@ As with `ItemReader`,
 ----
 public interface ItemWriter<T> {
 
-    void write(List<? extends T> items) throws Exception;
+    void write(Chunk<? extends T> items) throws Exception;
 
 }
 ----
@@ -2732,7 +2732,7 @@ public class CustomItemWriter<T> implements ItemWriter<T> {
 
     List<T> output = TransactionAwareProxyFactory.createTransactionalList();
 
-    public void write(List<? extends T> items) throws Exception {
+    public void write(Chunk<? extends T> items) throws Exception {
         output.addAll(items);
     }
 

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/Chunk.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2013 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,9 +14,11 @@
  * limitations under the License.
  */
 
-package org.springframework.batch.core.step.item;
+package org.springframework.batch.item;
 
+import java.io.Serializable;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
@@ -26,13 +28,14 @@ import java.util.List;
  * Encapsulation of a list of items to be processed and possibly a list of failed items to
  * be skipped. To mark an item as skipped clients should iterate over the chunk using the
  * {@link #iterator()} method, and if there is a failure call
- * {@link org.springframework.batch.core.step.item.Chunk.ChunkIterator#remove()} on the
- * iterator. The skipped items are then available through the chunk.
+ * {@link Chunk.ChunkIterator#remove()} on the iterator. The skipped items are then
+ * available through the chunk.
  *
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  * @since 2.0
  */
-public class Chunk<W> implements Iterable<W> {
+public class Chunk<W> implements Iterable<W>, Serializable {
 
 	private List<W> items = new ArrayList<>();
 
@@ -46,15 +49,19 @@ public class Chunk<W> implements Iterable<W> {
 
 	private boolean busy;
 
-	public Chunk() {
-		this(null, null);
+	public Chunk(W... items) {
+		this(Arrays.stream(items).toList());
 	}
 
-	public Chunk(Collection<? extends W> items) {
+	public static <W> Chunk<W> of(W... items) {
+		return new Chunk<>(items);
+	}
+
+	public Chunk(List<? extends W> items) {
 		this(items, null);
 	}
 
-	public Chunk(Collection<? extends W> items, List<SkipWrapper<W>> skips) {
+	public Chunk(List<? extends W> items, List<SkipWrapper<W>> skips) {
 		super();
 		if (items != null) {
 			this.items = new ArrayList<>(items);
@@ -72,6 +79,14 @@ public class Chunk<W> implements Iterable<W> {
 		items.add(item);
 	}
 
+	/**
+	 * Add all items to the chunk.
+	 * @param items the items to add
+	 */
+	public void addAll(List<W> items) {
+		this.items.addAll(items);
+	}
+
 	/**
 	 * Clear the items down to signal that we are done.
 	 */

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/ItemWriter.java

@@ -18,6 +18,8 @@ package org.springframework.batch.item;
 
 import java.util.List;
 
+import org.springframework.lang.NonNull;
+
 /**
  * <p>
  * Basic interface for generic output operations. Class implementing this interface will
@@ -36,6 +38,7 @@ import java.util.List;
  * @author Dave Syer
  * @author Lucas Ward
  * @author Taeik Lim
+ * @author Mahmoud Ben Hassine
  */
 @FunctionalInterface
 public interface ItemWriter<T> {
@@ -43,10 +46,10 @@ public interface ItemWriter<T> {
 	/**
 	 * Process the supplied data element. Will not be called with any null items in normal
 	 * operation.
-	 * @param items items to be written
+	 * @param chunk of items to be written. Must not be {@code null}.
 	 * @throws Exception if there are errors. The framework will catch the exception and
 	 * convert or rethrow it as appropriate.
 	 */
-	void write(List<? extends T> items) throws Exception;
+	void write(@NonNull Chunk<? extends T> chunk) throws Exception;
 
 }

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/KeyValueItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
  * the License. You may obtain a copy of the License at
@@ -23,6 +23,7 @@ import org.springframework.util.Assert;
  * a {@link Converter} to derive a key from an item
  *
  * @author David Turanski
+ * @author Mahmoud Ben Hassine
  * @since 2.2
  *
  */
@@ -38,7 +39,7 @@ public abstract class KeyValueItemWriter<K, V> implements ItemWriter<V>, Initial
 	 * @see org.springframework.batch.item.ItemWriter#write(java.util.List)
 	 */
 	@Override
-	public void write(List<? extends V> items) throws Exception {
+	public void write(Chunk<? extends V> items) throws Exception {
 		if (items == null) {
 			return;
 		}

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/SkipWrapper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2018 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.batch.core.step.item;
+package org.springframework.batch.item;
 
 import org.springframework.lang.Nullable;
 

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/adapter/ItemWriterAdapter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2013 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@ package org.springframework.batch.item.adapter;
 
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 
 /**
@@ -26,11 +27,12 @@ import org.springframework.batch.item.ItemWriter;
  *
  * @see PropertyExtractingDelegatingItemWriter
  * @author Robert Kasanicky
+ * @author Mahmoud Ben Hassine
  */
 public class ItemWriterAdapter<T> extends AbstractMethodInvokingDelegator<T> implements ItemWriter<T> {
 
 	@Override
-	public void write(List<? extends T> items) throws Exception {
+	public void write(Chunk<? extends T> items) throws Exception {
 		for (T item : items) {
 			invokeDelegateMethodWithArgument(item);
 		}

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/adapter/PropertyExtractingDelegatingItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2013 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@ package org.springframework.batch.item.adapter;
 import java.util.Arrays;
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.beans.BeanWrapper;
 import org.springframework.beans.BeanWrapperImpl;
@@ -30,6 +31,7 @@ import org.springframework.util.Assert;
  *
  * @see ItemWriterAdapter
  * @author Robert Kasanicky
+ * @author Mahmoud Ben Hassine
  */
 public class PropertyExtractingDelegatingItemWriter<T> extends AbstractMethodInvokingDelegator<T>
 		implements ItemWriter<T> {
@@ -41,7 +43,7 @@ public class PropertyExtractingDelegatingItemWriter<T> extends AbstractMethodInv
 	 * passes them as arguments to the delegate method.
 	 */
 	@Override
-	public void write(List<? extends T> items) throws Exception {
+	public void write(Chunk<? extends T> items) throws Exception {
 		for (T item : items) {
 
 			// helper for extracting property values from a bean

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/amqp/AmqpItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2018 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@ package org.springframework.batch.item.amqp;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.springframework.amqp.core.AmqpTemplate;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.util.Assert;
 
@@ -47,7 +48,7 @@ public class AmqpItemWriter<T> implements ItemWriter<T> {
 	}
 
 	@Override
-	public void write(final List<? extends T> items) throws Exception {
+	public void write(final Chunk<? extends T> items) throws Exception {
 		if (log.isDebugEnabled()) {
 			log.debug("Writing to AMQP with " + items.size() + " items.");
 		}

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/avro/AvroItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2021 the original author or authors.
+ * Copyright 2019-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,6 +31,7 @@ import org.apache.avro.reflect.ReflectDatumWriter;
 import org.apache.avro.specific.SpecificDatumWriter;
 import org.apache.avro.specific.SpecificRecordBase;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.ItemStreamException;
 import org.springframework.batch.item.ItemWriter;
@@ -84,7 +85,7 @@ public class AvroItemWriter<T> extends AbstractItemStreamItemWriter<T> {
 	}
 
 	@Override
-	public void write(List<? extends T> items) throws Exception {
+	public void write(Chunk<? extends T> items) throws Exception {
 		items.forEach(item -> {
 			try {
 				if (this.dataFileWriter != null) {

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/data/MongoItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,6 +22,7 @@ import java.util.List;
 import org.bson.Document;
 import org.bson.types.ObjectId;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.data.mongodb.core.BulkOperations;
@@ -113,39 +114,39 @@ public class MongoItemWriter<T> implements ItemWriter<T>, InitializingBean {
 	 * If a transaction is active, buffer items to be written just before commit.
 	 * Otherwise write items using the provided template.
 	 *
-	 * @see org.springframework.batch.item.ItemWriter#write(List)
+	 * @see org.springframework.batch.item.ItemWriter#write(Chunk)
 	 */
 	@Override
-	public void write(List<? extends T> items) throws Exception {
+	public void write(Chunk<? extends T> chunk) throws Exception {
 		if (!transactionActive()) {
-			doWrite(items);
+			doWrite(chunk);
 			return;
 		}
 
-		List<T> bufferedItems = getCurrentBuffer();
-		bufferedItems.addAll(items);
+		Chunk bufferedItems = getCurrentBuffer();
+		bufferedItems.addAll(chunk.getItems());
 	}
 
 	/**
 	 * Performs the actual write to the store via the template. This can be overridden by
 	 * a subclass if necessary.
-	 * @param items the list of items to be persisted.
+	 * @param chunk the chunk of items to be persisted.
 	 */
-	protected void doWrite(List<? extends T> items) {
-		if (!CollectionUtils.isEmpty(items)) {
+	protected void doWrite(Chunk<? extends T> chunk) {
+		if (!CollectionUtils.isEmpty(chunk.getItems())) {
 			if (this.delete) {
-				delete(items);
+				delete(chunk);
 			}
 			else {
-				saveOrUpdate(items);
+				saveOrUpdate(chunk);
 			}
 		}
 	}
 
-	private void delete(List<? extends T> items) {
-		BulkOperations bulkOperations = initBulkOperations(BulkMode.ORDERED, items.get(0));
+	private void delete(Chunk<? extends T> chunk) {
+		BulkOperations bulkOperations = initBulkOperations(BulkMode.ORDERED, chunk.getItems().get(0));
 		MongoConverter mongoConverter = this.template.getConverter();
-		for (Object item : items) {
+		for (Object item : chunk) {
 			Document document = new Document();
 			mongoConverter.write(item, document);
 			Object objectId = document.get(ID_KEY);
@@ -157,11 +158,11 @@ public class MongoItemWriter<T> implements ItemWriter<T>, InitializingBean {
 		bulkOperations.execute();
 	}
 
-	private void saveOrUpdate(List<? extends T> items) {
-		BulkOperations bulkOperations = initBulkOperations(BulkMode.ORDERED, items.get(0));
+	private void saveOrUpdate(Chunk<? extends T> chunk) {
+		BulkOperations bulkOperations = initBulkOperations(BulkMode.ORDERED, chunk.getItems().get(0));
 		MongoConverter mongoConverter = this.template.getConverter();
 		FindAndReplaceOptions upsert = new FindAndReplaceOptions().upsert();
-		for (Object item : items) {
+		for (Object item : chunk) {
 			Document document = new Document();
 			mongoConverter.write(item, document);
 			Object objectId = document.get(ID_KEY) != null ? document.get(ID_KEY) : new ObjectId();
@@ -186,19 +187,18 @@ public class MongoItemWriter<T> implements ItemWriter<T>, InitializingBean {
 		return TransactionSynchronizationManager.isActualTransactionActive();
 	}
 
-	@SuppressWarnings("unchecked")
-	private List<T> getCurrentBuffer() {
+	private Chunk<T> getCurrentBuffer() {
 		if (!TransactionSynchronizationManager.hasResource(bufferKey)) {
-			TransactionSynchronizationManager.bindResource(bufferKey, new ArrayList<T>());
+			TransactionSynchronizationManager.bindResource(bufferKey, new Chunk<T>());
 
 			TransactionSynchronizationManager.registerSynchronization(new TransactionSynchronization() {
 				@Override
 				public void beforeCommit(boolean readOnly) {
-					List<T> items = (List<T>) TransactionSynchronizationManager.getResource(bufferKey);
+					Chunk<T> chunk = (Chunk<T>) TransactionSynchronizationManager.getResource(bufferKey);
 
-					if (!CollectionUtils.isEmpty(items)) {
+					if (!CollectionUtils.isEmpty(chunk.getItems())) {
 						if (!readOnly) {
-							doWrite(items);
+							doWrite(chunk);
 						}
 					}
 				}
@@ -212,7 +212,7 @@ public class MongoItemWriter<T> implements ItemWriter<T>, InitializingBean {
 			});
 		}
 
-		return (List<T>) TransactionSynchronizationManager.getResource(bufferKey);
+		return (Chunk<T>) TransactionSynchronizationManager.getResource(bufferKey);
 	}
 
 	@Override

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/data/Neo4jItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,7 @@ import org.apache.commons.logging.LogFactory;
 import org.neo4j.ogm.session.Session;
 import org.neo4j.ogm.session.SessionFactory;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.util.Assert;
@@ -86,12 +87,12 @@ public class Neo4jItemWriter<T> implements ItemWriter<T>, InitializingBean {
 	/**
 	 * Write all items to the data store.
 	 *
-	 * @see org.springframework.batch.item.ItemWriter#write(java.util.List)
+	 * @see org.springframework.batch.item.ItemWriter#write(Chunk)
 	 */
 	@Override
-	public void write(List<? extends T> items) throws Exception {
-		if (!CollectionUtils.isEmpty(items)) {
-			doWrite(items);
+	public void write(Chunk<? extends T> chunk) throws Exception {
+		if (!CollectionUtils.isEmpty(chunk.getItems())) {
+			doWrite(chunk);
 		}
 	}
 
@@ -100,7 +101,7 @@ public class Neo4jItemWriter<T> implements ItemWriter<T>, InitializingBean {
 	 * if necessary.
 	 * @param items the list of items to be persisted.
 	 */
-	protected void doWrite(List<? extends T> items) {
+	protected void doWrite(Chunk<? extends T> items) {
 		if (delete) {
 			delete(items);
 		}
@@ -109,7 +110,7 @@ public class Neo4jItemWriter<T> implements ItemWriter<T>, InitializingBean {
 		}
 	}
 
-	private void delete(List<? extends T> items) {
+	private void delete(Chunk<? extends T> items) {
 		Session session = this.sessionFactory.openSession();
 
 		for (T item : items) {
@@ -117,7 +118,7 @@ public class Neo4jItemWriter<T> implements ItemWriter<T>, InitializingBean {
 		}
 	}
 
-	private void save(List<? extends T> items) {
+	private void save(Chunk<? extends T> items) {
 		Session session = this.sessionFactory.openSession();
 
 		for (T item : items) {

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/data/RepositoryItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,8 @@ import java.util.List;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.item.adapter.AbstractMethodInvokingDelegator.InvocationTargetThrowableWrapper;
 import org.springframework.batch.item.adapter.DynamicMethodInvocationException;
@@ -87,12 +89,12 @@ public class RepositoryItemWriter<T> implements ItemWriter<T>, InitializingBean
 	/**
 	 * Write all items to the data store via a Spring Data repository.
 	 *
-	 * @see org.springframework.batch.item.ItemWriter#write(java.util.List)
+	 * @see org.springframework.batch.item.ItemWriter#write(Chunk)
 	 */
 	@Override
-	public void write(List<? extends T> items) throws Exception {
-		if (!CollectionUtils.isEmpty(items)) {
-			doWrite(items);
+	public void write(Chunk<? extends T> chunk) throws Exception {
+		if (!CollectionUtils.isEmpty(chunk.getItems())) {
+			doWrite(chunk);
 		}
 	}
 
@@ -102,7 +104,7 @@ public class RepositoryItemWriter<T> implements ItemWriter<T>, InitializingBean
 	 * @param items the list of items to be persisted.
 	 * @throws Exception thrown if error occurs during writing.
 	 */
-	protected void doWrite(List<? extends T> items) throws Exception {
+	protected void doWrite(Chunk<? extends T> items) throws Exception {
 		if (logger.isDebugEnabled()) {
 			logger.debug("Writing to the repository with " + items.size() + " items.");
 		}

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/database/HibernateItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2021 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,7 @@ import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.hibernate.context.spi.CurrentSessionContext;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.util.Assert;
@@ -81,10 +82,10 @@ public class HibernateItemWriter<T> implements ItemWriter<T>, InitializingBean {
 	 * Save or update any entities not in the current hibernate session and then flush the
 	 * hibernate session.
 	 *
-	 * @see org.springframework.batch.item.ItemWriter#write(java.util.List)
+	 * @see org.springframework.batch.item.ItemWriter#write(Chunk)
 	 */
 	@Override
-	public void write(List<? extends T> items) {
+	public void write(Chunk<? extends T> items) {
 		doWrite(sessionFactory, items);
 		sessionFactory.getCurrentSession().flush();
 		if (clearSession) {
@@ -98,7 +99,7 @@ public class HibernateItemWriter<T> implements ItemWriter<T>, InitializingBean {
 	 * @param sessionFactory Hibernate SessionFactory to be used
 	 * @param items the list of items to use for the write
 	 */
-	protected void doWrite(SessionFactory sessionFactory, List<? extends T> items) {
+	protected void doWrite(SessionFactory sessionFactory, Chunk<? extends T> items) {
 		if (logger.isDebugEnabled()) {
 			logger.debug("Writing to Hibernate with " + items.size() + " items.");
 		}

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/database/JdbcBatchItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2021 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,6 +25,7 @@ import javax.sql.DataSource;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.dao.DataAccessException;
@@ -51,7 +52,7 @@ import org.springframework.util.Assert;
  * be responsible for mapping the item to the parameters needed to execute the SQL
  * statement.<br>
  *
- * It is expected that {@link #write(List)} is called inside a transaction.<br>
+ * It is expected that {@link #write(Chunk)} is called inside a transaction.<br>
  *
  * The writer is thread-safe after its properties are set (normal singleton behavior), so
  * it can be used to write in multiple concurrent transactions.
@@ -59,6 +60,7 @@ import org.springframework.util.Assert;
  * @author Dave Syer
  * @author Thomas Risberg
  * @author Michael Minella
+ * @author Mahmoud Ben Hassine
  * @since 2.0
  */
 public class JdbcBatchItemWriter<T> implements ItemWriter<T>, InitializingBean {
@@ -164,24 +166,25 @@ public class JdbcBatchItemWriter<T> implements ItemWriter<T>, InitializingBean {
 	 */
 	@SuppressWarnings("unchecked")
 	@Override
-	public void write(final List<? extends T> items) throws Exception {
+	public void write(final Chunk<? extends T> chunk) throws Exception {
 
-		if (!items.isEmpty()) {
+		if (!chunk.isEmpty()) {
 
 			if (logger.isDebugEnabled()) {
-				logger.debug("Executing batch with " + items.size() + " items.");
+				logger.debug("Executing batch with " + chunk.size() + " items.");
 			}
 
 			int[] updateCounts;
 
 			if (usingNamedParameters) {
-				if (items.get(0) instanceof Map && this.itemSqlParameterSourceProvider == null) {
-					updateCounts = namedParameterJdbcTemplate.batchUpdate(sql, items.toArray(new Map[items.size()]));
+				if (chunk.getItems().get(0) instanceof Map && this.itemSqlParameterSourceProvider == null) {
+					updateCounts = namedParameterJdbcTemplate.batchUpdate(sql,
+							chunk.getItems().toArray(new Map[chunk.size()]));
 				}
 				else {
-					SqlParameterSource[] batchArgs = new SqlParameterSource[items.size()];
+					SqlParameterSource[] batchArgs = new SqlParameterSource[chunk.size()];
 					int i = 0;
-					for (T item : items) {
+					for (T item : chunk) {
 						batchArgs[i++] = itemSqlParameterSourceProvider.createSqlParameterSource(item);
 					}
 					updateCounts = namedParameterJdbcTemplate.batchUpdate(sql, batchArgs);
@@ -193,7 +196,7 @@ public class JdbcBatchItemWriter<T> implements ItemWriter<T>, InitializingBean {
 							@Override
 							public int[] doInPreparedStatement(PreparedStatement ps)
 									throws SQLException, DataAccessException {
-								for (T item : items) {
+								for (T item : chunk) {
 									itemPreparedStatementSetter.setValues(item, ps);
 									ps.addBatch();
 								}
@@ -207,7 +210,7 @@ public class JdbcBatchItemWriter<T> implements ItemWriter<T>, InitializingBean {
 					int value = updateCounts[i];
 					if (value == 0) {
 						throw new EmptyResultDataAccessException("Item " + i + " of " + updateCounts.length
-								+ " did not update any rows: [" + items.get(i) + "]", 1);
+								+ " did not update any rows: [" + chunk.getItems().get(i) + "]", 1);
 					}
 				}
 			}

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/database/JpaItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2021 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,8 @@ package org.springframework.batch.item.database;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.dao.DataAccessResourceFailureException;
@@ -32,7 +34,7 @@ import java.util.List;
  * {@link org.springframework.batch.item.ItemWriter} that is using a JPA
  * EntityManagerFactory to merge any Entities that aren't part of the persistence context.
  *
- * It is required that {@link #write(List)} is called inside a transaction.<br>
+ * It is required that {@link #write(Chunk)} is called inside a transaction.<br>
  *
  * The reader must be configured with an {@link jakarta.persistence.EntityManagerFactory}
  * that is capable of participating in Spring managed transactions.
@@ -80,10 +82,10 @@ public class JpaItemWriter<T> implements ItemWriter<T>, InitializingBean {
 	 * Merge all provided items that aren't already in the persistence context and then
 	 * flush the entity manager.
 	 *
-	 * @see org.springframework.batch.item.ItemWriter#write(java.util.List)
+	 * @see org.springframework.batch.item.ItemWriter#write(Chunk)
 	 */
 	@Override
-	public void write(List<? extends T> items) {
+	public void write(Chunk<? extends T> items) {
 		EntityManager entityManager = EntityManagerFactoryUtils.getTransactionalEntityManager(entityManagerFactory);
 		if (entityManager == null) {
 			throw new DataAccessResourceFailureException("Unable to obtain a transactional EntityManager");
@@ -98,7 +100,7 @@ public class JpaItemWriter<T> implements ItemWriter<T>, InitializingBean {
 	 * @param entityManager the EntityManager to use for the operation
 	 * @param items the list of items to use for the write
 	 */
-	protected void doWrite(EntityManager entityManager, List<? extends T> items) {
+	protected void doWrite(EntityManager entityManager, Chunk<? extends T> items) {
 
 		if (logger.isDebugEnabled()) {
 			logger.debug("Writing to JPA with " + items.size() + " items.");

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/FlatFileItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2018 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@ package org.springframework.batch.item.file;
 
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.file.transform.LineAggregator;
 import org.springframework.batch.item.support.AbstractFileItemWriter;
 import org.springframework.core.io.Resource;
@@ -71,7 +72,7 @@ public class FlatFileItemWriter<T> extends AbstractFileItemWriter<T> {
 	}
 
 	@Override
-	public String doWrite(List<? extends T> items) {
+	public String doWrite(Chunk<? extends T> items) {
 		StringBuilder lines = new StringBuilder();
 		for (T item : items) {
 			lines.append(this.lineAggregator.aggregate(item)).append(this.lineSeparator);

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/MultiResourceItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2017 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,8 @@ package org.springframework.batch.item.file;
 import java.io.File;
 import java.io.IOException;
 import java.util.List;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.ItemStreamException;
 import org.springframework.batch.item.support.AbstractItemStreamItemWriter;
@@ -39,6 +41,7 @@ import org.springframework.util.ClassUtils;
  *
  * @param <T> item type
  * @author Robert Kasanicky
+ * @author Mahmoud Ben Hassine
  */
 public class MultiResourceItemWriter<T> extends AbstractItemStreamItemWriter<T> {
 
@@ -67,7 +70,7 @@ public class MultiResourceItemWriter<T> extends AbstractItemStreamItemWriter<T>
 	}
 
 	@Override
-	public void write(List<? extends T> items) throws Exception {
+	public void write(Chunk<? extends T> items) throws Exception {
 		if (!opened) {
 			File file = setResourceToDelegate();
 			// create only if write is called

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/jms/JmsItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2007 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,8 @@ package org.springframework.batch.item.jms;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.jms.core.JmsOperations;
 import org.springframework.jms.core.JmsTemplate;
@@ -27,13 +29,14 @@ import java.util.List;
 
 /**
  * An {@link ItemWriter} for JMS using a {@link JmsTemplate}. The template should have a
- * default destination, which will be used to send items in {@link #write(List)}.<br>
+ * default destination, which will be used to send items in {@link #write(Chunk)}.<br>
  * <br>
  *
  * The implementation is thread-safe after its properties are set (normal singleton
  * behavior).
  *
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  *
  */
 public class JmsItemWriter<T> implements ItemWriter<T> {
@@ -58,10 +61,10 @@ public class JmsItemWriter<T> implements ItemWriter<T> {
 	/**
 	 * Send the items one-by-one to the default destination of the JMS template.
 	 *
-	 * @see org.springframework.batch.item.ItemWriter#write(java.util.List)
+	 * @see org.springframework.batch.item.ItemWriter#write(Chunk)
 	 */
 	@Override
-	public void write(List<? extends T> items) throws Exception {
+	public void write(Chunk<? extends T> items) throws Exception {
 
 		if (logger.isDebugEnabled()) {
 			logger.debug("Writing to JMS with " + items.size() + " items.");

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/json/JsonFileItemWriter.java

@@ -19,6 +19,7 @@ package org.springframework.batch.item.json;
 import java.util.Iterator;
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.support.AbstractFileItemWriter;
 import org.springframework.core.io.WritableResource;
 import org.springframework.util.Assert;
@@ -94,7 +95,7 @@ public class JsonFileItemWriter<T> extends AbstractFileItemWriter<T> {
 	}
 
 	@Override
-	public String doWrite(List<? extends T> items) {
+	public String doWrite(Chunk<? extends T> items) {
 		StringBuilder lines = new StringBuilder();
 		Iterator<? extends T> iterator = items.iterator();
 		if (!items.isEmpty() && state.getLinesWritten() > 0) {

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/mail/SimpleMailMessageItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2010 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.mail.MailException;
@@ -50,6 +51,7 @@ import org.springframework.util.Assert;
  * </p>
  *
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  * @since 2.1
  *
  */
@@ -60,7 +62,7 @@ public class SimpleMailMessageItemWriter implements ItemWriter<SimpleMailMessage
 	private MailErrorHandler mailErrorHandler = new DefaultMailErrorHandler();
 
 	/**
-	 * A {@link MailSender} to be used to send messages in {@link #write(List)}.
+	 * A {@link MailSender} to be used to send messages in {@link #write(Chunk)}.
 	 * @param mailSender The {@link MailSender} to be used.
 	 */
 	public void setMailSender(MailSender mailSender) {
@@ -87,13 +89,13 @@ public class SimpleMailMessageItemWriter implements ItemWriter<SimpleMailMessage
 	}
 
 	/**
-	 * @param items the items to send
-	 * @see ItemWriter#write(List)
+	 * @param chunk the chunk of items to send
+	 * @see ItemWriter#write(Chunk)
 	 */
 	@Override
-	public void write(List<? extends SimpleMailMessage> items) throws MailException {
+	public void write(Chunk<? extends SimpleMailMessage> chunk) throws MailException {
 		try {
-			mailSender.send(items.toArray(new SimpleMailMessage[items.size()]));
+			mailSender.send(chunk.getItems().toArray(new SimpleMailMessage[chunk.size()]));
 		}
 		catch (MailSendException e) {
 			Map<Object, Exception> failedMessages = e.getFailedMessages();

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/mail/builder/SimpleMailMessageItemWriterBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 the original author or authors.
+ * Copyright 2017-2022 the original author or authors.
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -28,6 +28,7 @@ import org.springframework.util.Assert;
  * Creates a fully qualified SimpleMailMessageItemWriter.
  *
  * @author Glenn Renfro
+ * @author Mahmoud Ben Hassine
  * @since 4.0
  */
 
@@ -39,7 +40,7 @@ public class SimpleMailMessageItemWriterBuilder {
 
 	/**
 	 * A {@link MailSender} to be used to send messages in
-	 * {@link SimpleMailMessageItemWriter#write(List)}.
+	 * {@link SimpleMailMessageItemWriter#write(Chunk)}.
 	 * @param mailSender strategy for sending simple mails.
 	 * @return this instance for method chaining.
 	 * @see SimpleMailMessageItemWriter#setMailSender(MailSender)

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/mail/javamail/MimeMessageItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2021 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,6 +15,7 @@
  */
 package org.springframework.batch.item.mail.javamail;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.item.mail.DefaultMailErrorHandler;
 import org.springframework.batch.item.mail.MailErrorHandler;
@@ -64,7 +65,7 @@ public class MimeMessageItemWriter implements ItemWriter<MimeMessage> {
 	private MailErrorHandler mailErrorHandler = new DefaultMailErrorHandler();
 
 	/**
-	 * A {@link JavaMailSender} to be used to send messages in {@link #write(List)}.
+	 * A {@link JavaMailSender} to be used to send messages in {@link #write(Chunk)}.
 	 * @param mailSender service for doing the work of sending a MIME message
 	 */
 	public void setJavaMailSender(JavaMailSender mailSender) {
@@ -90,13 +91,13 @@ public class MimeMessageItemWriter implements ItemWriter<MimeMessage> {
 	}
 
 	/**
-	 * @param items the items to send
-	 * @see ItemWriter#write(List)
+	 * @param chunk the chunk of items to send
+	 * @see ItemWriter#write(Chunk)
 	 */
 	@Override
-	public void write(List<? extends MimeMessage> items) throws MailException {
+	public void write(Chunk<? extends MimeMessage> chunk) throws MailException {
 		try {
-			mailSender.send(items.toArray(new MimeMessage[items.size()]));
+			mailSender.send(chunk.getItems().toArray(new MimeMessage[chunk.size()]));
 		}
 		catch (MailSendException e) {
 			Map<Object, Exception> failedMessages = e.getFailedMessages();

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/support/AbstractFileItemWriter.java

@@ -31,6 +31,7 @@ import java.util.List;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.ItemStream;
 import org.springframework.batch.item.ItemStreamException;
@@ -220,7 +221,7 @@ public abstract class AbstractFileItemWriter<T> extends AbstractItemStreamItemWr
 	 * @throws Exception if an error occurs while writing items to the output stream
 	 */
 	@Override
-	public void write(List<? extends T> items) throws Exception {
+	public void write(Chunk<? extends T> items) throws Exception {
 		if (!getOutputState().isInitialized()) {
 			throw new WriterNotOpenException("Writer must be open before it can be written to");
 		}
@@ -247,7 +248,7 @@ public abstract class AbstractFileItemWriter<T> extends AbstractItemStreamItemWr
 	 * @param items to be written
 	 * @return written lines
 	 */
-	protected abstract String doWrite(List<? extends T> items);
+	protected abstract String doWrite(Chunk<? extends T> items);
 
 	/**
 	 * @see ItemStream#close()

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/support/ClassifierCompositeItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2007 the original author or authors.
+ * Copyright 2006-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,7 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.classify.Classifier;
 import org.springframework.classify.ClassifierSupport;
 import org.springframework.batch.item.ItemWriter;
@@ -34,6 +35,7 @@ import org.springframework.util.Assert;
  *
  * @author Dave Syer
  * @author Glenn Renfro
+ * @author Mahmoud Ben Hassine
  * @since 2.0
  */
 public class ClassifierCompositeItemWriter<T> implements ItemWriter<T> {
@@ -53,14 +55,14 @@ public class ClassifierCompositeItemWriter<T> implements ItemWriter<T> {
 	 * classification by the {@link Classifier}.
 	 */
 	@Override
-	public void write(List<? extends T> items) throws Exception {
+	public void write(Chunk<? extends T> items) throws Exception {
 
-		Map<ItemWriter<? super T>, List<T>> map = new LinkedHashMap<>();
+		Map<ItemWriter<? super T>, Chunk<T>> map = new LinkedHashMap<>();
 
 		for (T item : items) {
 			ItemWriter<? super T> key = classifier.classify(item);
 			if (!map.containsKey(key)) {
-				map.put(key, new ArrayList<>());
+				map.put(key, new Chunk<>());
 			}
 			map.get(key).add(item);
 		}

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/support/CompositeItemWriter.java

@@ -16,6 +16,7 @@
 
 package org.springframework.batch.item.support;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.ItemStream;
 import org.springframework.batch.item.ItemStreamException;
@@ -35,6 +36,7 @@ import java.util.List;
  *
  * @author Robert Kasanicky
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  */
 public class CompositeItemWriter<T> implements ItemStreamWriter<T>, InitializingBean {
 
@@ -78,9 +80,9 @@ public class CompositeItemWriter<T> implements ItemStreamWriter<T>, Initializing
 	}
 
 	@Override
-	public void write(List<? extends T> item) throws Exception {
+	public void write(Chunk<? extends T> chunk) throws Exception {
 		for (ItemWriter<? super T> writer : delegates) {
-			writer.write(item);
+			writer.write(chunk);
 		}
 	}
 

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/support/ListItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2019 the original author or authors.
+ * Copyright 2014-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,6 +15,7 @@
  */
 package org.springframework.batch.item.support;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 
 import java.util.ArrayList;
@@ -22,14 +23,15 @@ import java.util.List;
 
 /**
  * @author mminella
+ * @author Mahmoud Ben Hassine
  */
 public class ListItemWriter<T> implements ItemWriter<T> {
 
 	private List<T> writtenItems = new ArrayList<>();
 
 	@Override
-	public void write(List<? extends T> items) throws Exception {
-		writtenItems.addAll(items);
+	public void write(Chunk<? extends T> chunk) throws Exception {
+		writtenItems.addAll(chunk.getItems());
 	}
 
 	public List<? extends T> getWrittenItems() {

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/support/SynchronizedItemStreamWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2020 the original author or authors.
+ * Copyright 2020-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,6 +15,7 @@
  */
 package org.springframework.batch.item.support;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.ItemStreamException;
 import org.springframework.batch.item.ItemStreamWriter;
@@ -60,7 +61,7 @@ public class SynchronizedItemStreamWriter<T> implements ItemStreamWriter<T>, Ini
 	 * This method delegates to the {@code write} method of the {@code delegate}.
 	 */
 	@Override
-	public synchronized void write(List<? extends T> items) throws Exception {
+	public synchronized void write(Chunk<? extends T> items) throws Exception {
 		this.delegate.write(items);
 	}
 

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/xml/StaxEventItemWriter.java

@@ -38,6 +38,7 @@ import javax.xml.transform.Result;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.ItemStreamException;
 import org.springframework.batch.item.ItemWriter;
@@ -761,7 +762,7 @@ public class StaxEventItemWriter<T> extends AbstractItemStreamItemWriter<T>
 	 * @throws XmlMappingException thrown if error occurs during XML Mapping.
 	 */
 	@Override
-	public void write(List<? extends T> items) throws XmlMappingException, IOException {
+	public void write(Chunk<? extends T> items) throws XmlMappingException, IOException {
 
 		if (!this.initialized) {
 			throw new WriterNotOpenException("Writer must be open before it can be written to");

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/adapter/ItemWriterAdapterTests.java

@@ -23,6 +23,8 @@ import java.util.ArrayList;
 import java.util.List;
 
 import org.junit.jupiter.api.Test;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.item.sample.Foo;
 import org.springframework.batch.item.sample.FooService;
@@ -33,6 +35,7 @@ import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
  * Tests for {@link ItemWriterAdapter}.
  *
  * @author Robert Kasanicky
+ * @author Mahmoud Ben Hassine
  */
 @SpringJUnitConfig(locations = "delegating-item-writer.xml")
 class ItemWriterAdapterTests {
@@ -50,7 +53,7 @@ class ItemWriterAdapterTests {
 	@Test
 	void testProcess() throws Exception {
 		Foo foo;
-		List<Foo> foos = new ArrayList<>();
+		Chunk<Foo> foos = new Chunk<>();
 		while ((foo = fooService.generateFoo()) != null) {
 			foos.add(foo);
 		}

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/adapter/PropertyExtractingDelegatingItemProcessorIntegrationTests.java

@@ -21,6 +21,7 @@ import org.junit.jupiter.api.Test;
 import java.util.Collections;
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.sample.Foo;
 import org.springframework.batch.item.sample.FooService;
 import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
@@ -49,7 +50,7 @@ class PropertyExtractingDelegatingItemProcessorIntegrationTests {
 	void testProcess() throws Exception {
 		Foo foo;
 		while ((foo = fooService.generateFoo()) != null) {
-			processor.write(Collections.singletonList(foo));
+			processor.write(Chunk.of(foo));
 		}
 
 		List<Foo> input = fooService.getGeneratedFoos();

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/amqp/AmqpItemWriterTests.java

@@ -21,6 +21,7 @@ import static org.mockito.Mockito.mock;
 
 import org.junit.jupiter.api.Test;
 import org.springframework.amqp.core.AmqpTemplate;
+import org.springframework.batch.item.Chunk;
 
 import java.util.Arrays;
 
@@ -31,6 +32,7 @@ import java.util.Arrays;
  *
  * @author Chris Schaefer
  * @author Will Schipp
+ * @author Mahmoud Ben Hassine
  */
 class AmqpItemWriterTests {
 
@@ -48,7 +50,7 @@ class AmqpItemWriterTests {
 		amqpTemplate.convertAndSend("bar");
 
 		AmqpItemWriter<String> amqpItemWriter = new AmqpItemWriter<>(amqpTemplate);
-		amqpItemWriter.write(Arrays.asList("foo", "bar"));
+		amqpItemWriter.write(Chunk.of("foo", "bar"));
 
 	}
 

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/amqp/builder/AmqpItemWriterBuilderTests.java

@@ -22,6 +22,7 @@ import org.junit.jupiter.api.Test;
 
 import org.springframework.amqp.core.AmqpTemplate;
 import org.springframework.amqp.core.Message;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.amqp.AmqpItemWriter;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -31,6 +32,7 @@ import static org.mockito.Mockito.verify;
 
 /**
  * @author Glenn Renfro
+ * @author Mahmoud Ben Hassine
  */
 class AmqpItemWriterBuilderTests {
 
@@ -46,7 +48,7 @@ class AmqpItemWriterBuilderTests {
 		AmqpTemplate amqpTemplate = mock(AmqpTemplate.class);
 
 		AmqpItemWriter<String> amqpItemWriter = new AmqpItemWriterBuilder<String>().amqpTemplate(amqpTemplate).build();
-		amqpItemWriter.write(Arrays.asList("foo", "bar"));
+		amqpItemWriter.write(Chunk.of("foo", "bar"));
 		verify(amqpTemplate).convertAndSend("foo");
 		verify(amqpTemplate).convertAndSend("bar");
 	}

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/avro/support/AvroItemReaderTestSupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019 the original author or authors.
+ * Copyright 2019-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@ package org.springframework.batch.item.avro.support;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.avro.AvroItemReader;
 
@@ -26,10 +27,11 @@ import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * @author David Turanski
+ * @author Mahmoud Ben Hassine
  */
 public abstract class AvroItemReaderTestSupport extends AvroTestFixtures {
 
-	protected <T> void verify(AvroItemReader<T> avroItemReader, List<T> actual) throws Exception {
+	protected <T> void verify(AvroItemReader<T> avroItemReader, Chunk<T> actual) throws Exception {
 
 		avroItemReader.open(new ExecutionContext());
 		List<T> users = new ArrayList<>();
@@ -40,7 +42,9 @@ public abstract class AvroItemReaderTestSupport extends AvroTestFixtures {
 		}
 
 		assertThat(users).hasSize(4);
-		assertThat(users).containsExactlyInAnyOrder(actual.get(0), actual.get(1), actual.get(2), actual.get(3));
+		List<T> actualItems = actual.getItems();
+		assertThat(users).containsExactlyInAnyOrder(actualItems.get(0), actualItems.get(1), actualItems.get(2),
+				actualItems.get(3));
 
 		avroItemReader.close();
 	}

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/avro/support/AvroItemWriterTestSupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019 the original author or authors.
+ * Copyright 2019-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,6 +25,7 @@ import java.net.URL;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.avro.AvroItemReader;
 import org.springframework.batch.item.avro.builder.AvroItemReaderBuilder;
@@ -36,22 +37,23 @@ import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * @author David Turanski
+ * @author Mahmoud Ben Hassine
  */
 public abstract class AvroItemWriterTestSupport extends AvroTestFixtures {
 
 	/*
 	 * This item reader configured for Specific Avro types.
 	 */
-	protected <T> void verifyRecords(byte[] bytes, List<T> actual, Class<T> clazz, boolean embeddedSchema)
+	protected <T> void verifyRecords(byte[] bytes, Chunk<T> actual, Class<T> clazz, boolean embeddedSchema)
 			throws Exception {
 		doVerify(bytes, clazz, actual, embeddedSchema);
 	}
 
-	protected <T> void verifyRecordsWithEmbeddedHeader(byte[] bytes, List<T> actual, Class<T> clazz) throws Exception {
+	protected <T> void verifyRecordsWithEmbeddedHeader(byte[] bytes, Chunk<T> actual, Class<T> clazz) throws Exception {
 		doVerify(bytes, clazz, actual, true);
 	}
 
-	private <T> void doVerify(byte[] bytes, Class<T> clazz, List<T> actual, boolean embeddedSchema) throws Exception {
+	private <T> void doVerify(byte[] bytes, Class<T> clazz, Chunk<T> actual, boolean embeddedSchema) throws Exception {
 		AvroItemReader<T> avroItemReader = new AvroItemReaderBuilder<T>().type(clazz)
 				.resource(new ByteArrayResource(bytes)).embeddedSchema(embeddedSchema).build();
 
@@ -63,7 +65,9 @@ public abstract class AvroItemWriterTestSupport extends AvroTestFixtures {
 			records.add(record);
 		}
 		assertThat(records).hasSize(4);
-		assertThat(records).containsExactlyInAnyOrder(actual.get(0), actual.get(1), actual.get(2), actual.get(3));
+		List<T> actualItems = actual.getItems();
+		assertThat(records).containsExactlyInAnyOrder(actualItems.get(0), actualItems.get(1), actualItems.get(2),
+				actualItems.get(3));
 	}
 
 	protected static class OutputStreamResource implements WritableResource {

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/avro/support/AvroTestFixtures.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019 the original author or authors.
+ * Copyright 2019-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -33,6 +33,8 @@ import org.apache.avro.io.Encoder;
 import org.apache.avro.io.EncoderFactory;
 import org.apache.avro.reflect.ReflectData;
 import org.apache.avro.reflect.ReflectDatumWriter;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.avro.example.User;
 import org.springframework.core.io.ByteArrayResource;
 import org.springframework.core.io.ClassPathResource;
@@ -45,13 +47,13 @@ import org.springframework.core.io.Resource;
 public abstract class AvroTestFixtures {
 
 	//@formatter:off
-	private final List<User> avroGeneratedUsers = Arrays.asList(
+	private final Chunk<User> avroGeneratedUsers = Chunk.of(
 			new User("David", 20, "blue"),
 			new User("Sue", 4, "red"),
 			new User("Alana", 13, "yellow"),
 			new User("Joe", 1, "pink"));
 
-	private List<PlainOldUser> plainOldUsers = Arrays.asList(
+	private Chunk<PlainOldUser> plainOldUsers = Chunk.of(
 			new PlainOldUser("David", 20, "blue"),
 			new PlainOldUser("Sue", 4, "red"),
 			new PlainOldUser("Alana", 13, "yellow"),
@@ -86,27 +88,28 @@ public abstract class AvroTestFixtures {
 		}
 	}
 
-	protected List<User> avroGeneratedUsers() {
+	protected Chunk<User> avroGeneratedUsers() {
 		return this.avroGeneratedUsers;
 	}
 
-	protected List<GenericRecord> genericAvroGeneratedUsers() {
-		return this.avroGeneratedUsers.stream().map(u -> {
+	protected Chunk<GenericRecord> genericAvroGeneratedUsers() {
+		return new Chunk(this.avroGeneratedUsers.getItems().stream().map(u -> {
 			GenericData.Record avroRecord;
 			avroRecord = new GenericData.Record(u.getSchema());
 			avroRecord.put("name", u.getName());
 			avroRecord.put("favorite_number", u.getFavoriteNumber());
 			avroRecord.put("favorite_color", u.getFavoriteColor());
 			return avroRecord;
-		}).collect(Collectors.toList());
+		}).collect(Collectors.toList()));
 	}
 
-	protected List<PlainOldUser> plainOldUsers() {
+	protected Chunk<PlainOldUser> plainOldUsers() {
 		return this.plainOldUsers;
 	}
 
-	protected List<GenericRecord> genericPlainOldUsers() {
-		return this.plainOldUsers.stream().map(PlainOldUser::toGenericRecord).collect(Collectors.toList());
+	protected Chunk<GenericRecord> genericPlainOldUsers() {
+		return new Chunk(
+				this.plainOldUsers.getItems().stream().map(PlainOldUser::toGenericRecord).collect(Collectors.toList()));
 	}
 
 	protected static class PlainOldUser {

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/data/GemfireItemWriterTests.java

@@ -27,6 +27,8 @@ import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.SpELItemKeyMapper;
 import org.springframework.data.gemfire.GemfireTemplate;
 import org.springframework.core.convert.converter.Converter;
@@ -61,29 +63,30 @@ class GemfireItemWriterTests {
 
 	@Test
 	void testBasicWrite() throws Exception {
-		List<Foo> items = new ArrayList<Foo>() {
+		Chunk<Foo> chunk = new Chunk<Foo>() {
 			{
 				add(new Foo(new Bar("val1")));
 				add(new Foo(new Bar("val2")));
 			}
 		};
 
-		writer.write(items);
+		writer.write(chunk);
 
+		List<Foo> items = chunk.getItems();
 		verify(template).put("val1", items.get(0));
 		verify(template).put("val2", items.get(1));
 	}
 
 	@Test
 	void testBasicDelete() throws Exception {
-		List<Foo> items = new ArrayList<Foo>() {
+		Chunk<Foo> chunk = new Chunk<Foo>() {
 			{
 				add(new Foo(new Bar("val1")));
 				add(new Foo(new Bar("val2")));
 			}
 		};
 		writer.setDelete(true);
-		writer.write(items);
+		writer.write(chunk);
 
 		verify(template).remove("val1");
 		verify(template).remove("val2");
@@ -91,7 +94,7 @@ class GemfireItemWriterTests {
 
 	@Test
 	void testWriteWithCustomItemKeyMapper() throws Exception {
-		List<Foo> items = new ArrayList<Foo>() {
+		Chunk<Foo> chunk = new Chunk<Foo>() {
 			{
 				add(new Foo(new Bar("val1")));
 				add(new Foo(new Bar("val2")));
@@ -108,8 +111,9 @@ class GemfireItemWriterTests {
 			}
 		});
 		writer.afterPropertiesSet();
-		writer.write(items);
+		writer.write(chunk);
 
+		List<Foo> items = chunk.getItems();
 		verify(template).put("item1", items.get(0));
 		verify(template).put("item2", items.get(1));
 	}

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/data/MongoItemWriterTests.java

@@ -38,6 +38,8 @@ import static org.mockito.Mockito.never;
 
 import org.mockito.junit.jupiter.MockitoSettings;
 import org.mockito.quality.Strictness;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.support.transaction.ResourcelessTransactionManager;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mongodb.core.BulkOperations;
@@ -104,7 +106,7 @@ class MongoItemWriterTests {
 
 	@Test
 	void testWriteNoTransactionNoCollection() throws Exception {
-		List<Item> items = Arrays.asList(new Item("Foo"), new Item("Bar"));
+		Chunk<Item> items = Chunk.of(new Item("Foo"), new Item("Bar"));
 
 		writer.write(items);
 
@@ -114,7 +116,7 @@ class MongoItemWriterTests {
 
 	@Test
 	void testWriteNoTransactionWithCollection() throws Exception {
-		List<Object> items = Arrays.asList(new Item("Foo"), new Item("Bar"));
+		Chunk<Object> items = Chunk.of(new Item("Foo"), new Item("Bar"));
 
 		writer.setCollection("collection");
 
@@ -126,7 +128,7 @@ class MongoItemWriterTests {
 
 	@Test
 	void testWriteNoTransactionNoItems() throws Exception {
-		writer.write(null);
+		writer.write(new Chunk<>());
 
 		verifyNoInteractions(template);
 		verifyNoInteractions(bulkOperations);
@@ -134,7 +136,7 @@ class MongoItemWriterTests {
 
 	@Test
 	void testWriteTransactionNoCollection() {
-		final List<Object> items = Arrays.asList(new Item("Foo"), new Item("Bar"));
+		final Chunk<Object> items = Chunk.of(new Item("Foo"), new Item("Bar"));
 
 		new TransactionTemplate(transactionManager).execute((TransactionCallback<Void>) status -> {
 			assertDoesNotThrow(() -> writer.write(items));
@@ -147,7 +149,7 @@ class MongoItemWriterTests {
 
 	@Test
 	void testWriteTransactionWithCollection() {
-		final List<Object> items = Arrays.asList(new Item("Foo"), new Item("Bar"));
+		final Chunk<Object> items = Chunk.of(new Item("Foo"), new Item("Bar"));
 
 		writer.setCollection("collection");
 
@@ -162,7 +164,7 @@ class MongoItemWriterTests {
 
 	@Test
 	void testWriteTransactionFails() {
-		final List<Object> items = Arrays.asList(new Item("Foo"), new Item("Bar"));
+		final Chunk<Object> items = Chunk.of(new Item("Foo"), new Item("Bar"));
 
 		writer.setCollection("collection");
 
@@ -183,7 +185,7 @@ class MongoItemWriterTests {
 	 */
 	@Test
 	void testWriteTransactionReadOnly() {
-		final List<Object> items = Arrays.asList(new Item("Foo"), new Item("Bar"));
+		final Chunk<Object> items = Chunk.of(new Item("Foo"), new Item("Bar"));
 
 		writer.setCollection("collection");
 
@@ -201,7 +203,7 @@ class MongoItemWriterTests {
 	@Test
 	void testRemoveNoObjectIdNoCollection() throws Exception {
 		writer.setDelete(true);
-		List<Object> items = Arrays.asList(new Item("Foo"), new Item("Bar"));
+		Chunk<Object> items = Chunk.of(new Item("Foo"), new Item("Bar"));
 
 		writer.write(items);
 
@@ -212,7 +214,7 @@ class MongoItemWriterTests {
 	@Test
 	void testRemoveNoObjectIdWithCollection() throws Exception {
 		writer.setDelete(true);
-		List<Object> items = Arrays.asList(new Item("Foo"), new Item("Bar"));
+		Chunk<Object> items = Chunk.of(new Item("Foo"), new Item("Bar"));
 
 		writer.setCollection("collection");
 		writer.write(items);
@@ -224,7 +226,7 @@ class MongoItemWriterTests {
 	@Test
 	void testRemoveNoTransactionNoCollection() throws Exception {
 		writer.setDelete(true);
-		List<Object> items = Arrays.asList(new Item(1), new Item(2));
+		Chunk<Object> items = Chunk.of(new Item(1), new Item(2));
 
 		writer.write(items);
 
@@ -235,7 +237,7 @@ class MongoItemWriterTests {
 	@Test
 	void testRemoveNoTransactionWithCollection() throws Exception {
 		writer.setDelete(true);
-		List<Object> items = Arrays.asList(new Item(1), new Item(2));
+		Chunk<Object> items = Chunk.of(new Item(1), new Item(2));
 
 		writer.setCollection("collection");
 
@@ -285,7 +287,7 @@ class MongoItemWriterTests {
 		new TransactionTemplate(transactionManager).execute((TransactionCallback<Void>) status -> {
 			try {
 				for (int i = 0; i < limit; i++) {
-					writers.get(i).write(Collections.singletonList(String.valueOf(i)));
+					writers.get(i).write(Chunk.of(String.valueOf(i)));
 				}
 			}
 			catch (Exception e) {

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/data/Neo4jItemWriterTests.java

@@ -25,6 +25,8 @@ import org.mockito.quality.Strictness;
 import org.neo4j.ogm.session.Session;
 import org.neo4j.ogm.session.SessionFactory;
 
+import org.springframework.batch.item.Chunk;
+
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.mockito.Mockito.verify;
@@ -62,32 +64,6 @@ class Neo4jItemWriterTests {
 		writer.afterPropertiesSet();
 	}
 
-	@Test
-	void testWriteNullSession() throws Exception {
-
-		writer = new Neo4jItemWriter<>();
-
-		writer.setSessionFactory(this.sessionFactory);
-		writer.afterPropertiesSet();
-
-		writer.write(null);
-
-		verifyNoInteractions(this.session);
-	}
-
-	@Test
-	void testWriteNullWithSession() throws Exception {
-		writer = new Neo4jItemWriter<>();
-
-		writer.setSessionFactory(this.sessionFactory);
-		writer.afterPropertiesSet();
-
-		when(this.sessionFactory.openSession()).thenReturn(this.session);
-		writer.write(null);
-
-		verifyNoInteractions(this.session);
-	}
-
 	@Test
 	void testWriteNoItemsWithSession() throws Exception {
 		writer = new Neo4jItemWriter<>();
@@ -96,7 +72,7 @@ class Neo4jItemWriterTests {
 		writer.afterPropertiesSet();
 
 		when(this.sessionFactory.openSession()).thenReturn(this.session);
-		writer.write(new ArrayList<>());
+		writer.write(new Chunk<>());
 
 		verifyNoInteractions(this.session);
 	}
@@ -108,7 +84,7 @@ class Neo4jItemWriterTests {
 		writer.setSessionFactory(this.sessionFactory);
 		writer.afterPropertiesSet();
 
-		List<String> items = new ArrayList<>();
+		Chunk<String> items = new Chunk<>();
 		items.add("foo");
 		items.add("bar");
 
@@ -126,7 +102,7 @@ class Neo4jItemWriterTests {
 		writer.setSessionFactory(this.sessionFactory);
 		writer.afterPropertiesSet();
 
-		List<String> items = new ArrayList<>();
+		Chunk<String> items = new Chunk<>();
 		items.add("foo");
 		items.add("bar");
 

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/data/RepositoryItemWriterTests.java

@@ -31,6 +31,8 @@ import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.data.repository.CrudRepository;
 
 @ExtendWith(MockitoExtension.class)
@@ -64,16 +66,14 @@ class RepositoryItemWriterTests {
 
 	@Test
 	void testWriteNoItems() throws Exception {
-		writer.write(null);
-
-		writer.write(new ArrayList<>());
+		writer.write(new Chunk<>());
 
 		verifyNoInteractions(repository);
 	}
 
 	@Test
 	void testWriteItems() throws Exception {
-		List<String> items = Collections.singletonList("foo");
+		Chunk<String> items = Chunk.of("foo");
 
 		writer.write(items);
 
@@ -83,7 +83,7 @@ class RepositoryItemWriterTests {
 
 	@Test
 	void testWriteItemsWithDefaultMethodName() throws Exception {
-		List<String> items = Collections.singletonList("foo");
+		Chunk<String> items = Chunk.of("foo");
 
 		writer.setMethodName(null);
 		writer.write(items);

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/data/builder/GemfireItemWriterBuilderTests.java

@@ -24,6 +24,8 @@ import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.SpELItemKeyMapper;
 import org.springframework.batch.item.data.GemfireItemWriter;
 import org.springframework.data.gemfire.GemfireTemplate;
@@ -35,6 +37,7 @@ import static org.mockito.Mockito.verify;
 
 /**
  * @author Glenn Renfro
+ * @author Mahmoud Ben Hassine
  */
 @ExtendWith(MockitoExtension.class)
 class GemfireItemWriterBuilderTests {
@@ -44,11 +47,11 @@ class GemfireItemWriterBuilderTests {
 
 	private SpELItemKeyMapper<String, GemfireItemWriterBuilderTests.Foo> itemKeyMapper;
 
-	private List<GemfireItemWriterBuilderTests.Foo> items;
+	private Chunk<Foo> items;
 
 	@BeforeEach
 	void setUp() {
-		this.items = Arrays.asList(new GemfireItemWriterBuilderTests.Foo(new GemfireItemWriterBuilderTests.Bar("val1")),
+		this.items = Chunk.of(new GemfireItemWriterBuilderTests.Foo(new GemfireItemWriterBuilderTests.Bar("val1")),
 				new GemfireItemWriterBuilderTests.Foo(new GemfireItemWriterBuilderTests.Bar("val2")));
 		this.itemKeyMapper = new SpELItemKeyMapper<>("bar.val");
 	}
@@ -60,8 +63,8 @@ class GemfireItemWriterBuilderTests {
 
 		writer.write(this.items);
 
-		verify(this.template).put("val1", items.get(0));
-		verify(this.template).put("val2", items.get(1));
+		verify(this.template).put("val1", items.getItems().get(0));
+		verify(this.template).put("val2", items.getItems().get(1));
 		verify(this.template, never()).remove("val1");
 		verify(this.template, never()).remove("val2");
 	}
@@ -75,8 +78,8 @@ class GemfireItemWriterBuilderTests {
 
 		verify(this.template).remove("val1");
 		verify(this.template).remove("val2");
-		verify(this.template, never()).put("val1", items.get(0));
-		verify(this.template, never()).put("val2", items.get(1));
+		verify(this.template, never()).put("val1", items.getItems().get(0));
+		verify(this.template, never()).put("val2", items.getItems().get(1));
 	}
 
 	@Test

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/data/builder/MongoItemWriterBuilderTests.java

@@ -31,6 +31,8 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 import org.mockito.junit.jupiter.MockitoSettings;
 import org.mockito.quality.Strictness;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.data.MongoItemWriter;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mongodb.core.BulkOperations;
@@ -68,9 +70,9 @@ class MongoItemWriterBuilderTests {
 
 	private MongoConverter mongoConverter;
 
-	private List<Item> saveItems;
+	private Chunk<Item> saveItems;
 
-	private List<Item> removeItems;
+	private Chunk<Item> removeItems;
 
 	@BeforeEach
 	void setUp() {
@@ -81,8 +83,8 @@ class MongoItemWriterBuilderTests {
 		mongoConverter = spy(new MappingMongoConverter(this.dbRefResolver, mappingContext));
 		when(this.template.getConverter()).thenReturn(mongoConverter);
 
-		this.saveItems = Arrays.asList(new Item("Foo"), new Item("Bar"));
-		this.removeItems = Arrays.asList(new Item(1), new Item(2));
+		this.saveItems = Chunk.of(new Item("Foo"), new Item("Bar"));
+		this.removeItems = Chunk.of(new Item(1), new Item(2));
 	}
 
 	@Test
@@ -91,8 +93,8 @@ class MongoItemWriterBuilderTests {
 		writer.write(this.saveItems);
 
 		verify(this.template).bulkOps(any(), any(Class.class));
-		verify(this.mongoConverter).write(eq(this.saveItems.get(0)), any(Document.class));
-		verify(this.mongoConverter).write(eq(this.saveItems.get(1)), any(Document.class));
+		verify(this.mongoConverter).write(eq(this.saveItems.getItems().get(0)), any(Document.class));
+		verify(this.mongoConverter).write(eq(this.saveItems.getItems().get(1)), any(Document.class));
 		verify(this.bulkOperations, times(2)).replaceOne(any(Query.class), any(Object.class), any());
 		verify(this.bulkOperations, never()).remove(any(Query.class));
 	}
@@ -105,8 +107,8 @@ class MongoItemWriterBuilderTests {
 		writer.write(this.saveItems);
 
 		verify(this.template).bulkOps(any(), eq("collection"));
-		verify(this.mongoConverter).write(eq(this.saveItems.get(0)), any(Document.class));
-		verify(this.mongoConverter).write(eq(this.saveItems.get(1)), any(Document.class));
+		verify(this.mongoConverter).write(eq(this.saveItems.getItems().get(0)), any(Document.class));
+		verify(this.mongoConverter).write(eq(this.saveItems.getItems().get(1)), any(Document.class));
 		verify(this.bulkOperations, times(2)).replaceOne(any(Query.class), any(Object.class), any());
 		verify(this.bulkOperations, never()).remove(any(Query.class));
 	}

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/data/builder/Neo4jItemWriterBuilderTests.java

@@ -26,6 +26,7 @@ import org.mockito.junit.jupiter.MockitoExtension;
 import org.neo4j.ogm.session.Session;
 import org.neo4j.ogm.session.SessionFactory;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.data.Neo4jItemWriter;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -36,6 +37,7 @@ import static org.mockito.Mockito.when;
 
 /**
  * @author Glenn Renfro
+ * @author Mahmoud Ben Hassine
  */
 @SuppressWarnings("deprecation")
 @ExtendWith(MockitoExtension.class)
@@ -51,7 +53,7 @@ class Neo4jItemWriterBuilderTests {
 	void testBasicWriter() throws Exception {
 		Neo4jItemWriter<String> writer = new Neo4jItemWriterBuilder<String>().sessionFactory(this.sessionFactory)
 				.build();
-		List<String> items = new ArrayList<>();
+		Chunk<String> items = new Chunk<>();
 		items.add("foo");
 		items.add("bar");
 
@@ -68,7 +70,7 @@ class Neo4jItemWriterBuilderTests {
 	void testBasicDelete() throws Exception {
 		Neo4jItemWriter<String> writer = new Neo4jItemWriterBuilder<String>().delete(true)
 				.sessionFactory(this.sessionFactory).build();
-		List<String> items = new ArrayList<>();
+		Chunk<String> items = new Chunk<>();
 		items.add("foo");
 		items.add("bar");
 

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/data/builder/RepositoryItemWriterBuilderTests.java

@@ -24,6 +24,8 @@ import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.data.RepositoryItemWriter;
 import org.springframework.data.repository.CrudRepository;
 
@@ -60,7 +62,7 @@ class RepositoryItemWriterBuilderTests {
 		RepositoryItemWriter<String> writer = new RepositoryItemWriterBuilder<String>().methodName("save")
 				.repository(this.repository).build();
 
-		List<String> items = Collections.singletonList("foo");
+		Chunk<String> items = Chunk.of("foo");
 
 		writer.write(items);
 
@@ -72,7 +74,7 @@ class RepositoryItemWriterBuilderTests {
 		RepositoryItemWriter<String> writer = new RepositoryItemWriterBuilder<String>().methodName("foo")
 				.repository(this.repository).build();
 
-		List<String> items = Collections.singletonList("foo");
+		Chunk<String> items = Chunk.of("foo");
 
 		writer.write(items);
 
@@ -88,7 +90,7 @@ class RepositoryItemWriterBuilderTests {
 		RepositoryItemWriter<String> writer = new RepositoryItemWriterBuilder<String>().methodName("foo")
 				.repository(repositoryMethodReference).build();
 
-		List<String> items = Collections.singletonList("foo");
+		Chunk<String> items = Chunk.of("foo");
 
 		writer.write(items);
 

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/database/HibernateItemWriterTests.java

@@ -23,6 +23,8 @@ import org.hibernate.SessionFactory;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.batch.item.Chunk;
+
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
@@ -84,7 +86,7 @@ class HibernateItemWriterTests {
 		this.currentSession.flush();
 		this.currentSession.clear();
 
-		List<String> items = Arrays.asList(new String[] { "foo", "bar" });
+		Chunk<String> items = Chunk.of("foo", "bar");
 		writer.write(items);
 
 	}
@@ -95,7 +97,7 @@ class HibernateItemWriterTests {
 		final RuntimeException ex = new RuntimeException("ERROR");
 		when(this.currentSession.contains("foo")).thenThrow(ex);
 
-		Exception exception = assertThrows(RuntimeException.class, () -> writer.write(List.of("foo")));
+		Exception exception = assertThrows(RuntimeException.class, () -> writer.write(Chunk.of("foo")));
 		assertEquals("ERROR", exception.getMessage());
 	}
 
@@ -109,7 +111,7 @@ class HibernateItemWriterTests {
 		currentSession.flush();
 		currentSession.clear();
 
-		List<String> items = Arrays.asList(new String[] { "foo", "bar" });
+		Chunk<String> items = Chunk.of("foo", "bar");
 		writer.write(items);
 	}
 
@@ -121,7 +123,7 @@ class HibernateItemWriterTests {
 		when(factory.getCurrentSession()).thenReturn(currentSession);
 		when(currentSession.contains("foo")).thenThrow(ex);
 
-		Exception exception = assertThrows(RuntimeException.class, () -> writer.write(List.of("foo")));
+		Exception exception = assertThrows(RuntimeException.class, () -> writer.write(Chunk.of("foo")));
 		assertEquals("ERROR", exception.getMessage());
 	}
 

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/database/JdbcBatchItemWriterClassicTests.java

@@ -27,6 +27,8 @@ import java.util.List;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.dao.DataAccessException;
 import org.springframework.dao.EmptyResultDataAccessException;
 import org.springframework.jdbc.UncategorizedSQLException;
@@ -38,6 +40,7 @@ import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
  * @author Dave Syer
  * @author Thomas Risberg
  * @author Will Schipp
+ * @author Mahmoud Ben Hassine
  */
 class JdbcBatchItemWriterClassicTests {
 
@@ -105,7 +108,7 @@ class JdbcBatchItemWriterClassicTests {
 	void testWriteAndFlush() throws Exception {
 		ps.addBatch();
 		when(ps.executeBatch()).thenReturn(new int[] { 123 });
-		writer.write(Collections.singletonList("bar"));
+		writer.write(Chunk.of("bar"));
 		assertEquals(2, list.size());
 		assertTrue(list.contains("SQL"));
 	}
@@ -114,7 +117,7 @@ class JdbcBatchItemWriterClassicTests {
 	void testWriteAndFlushWithEmptyUpdate() throws Exception {
 		ps.addBatch();
 		when(ps.executeBatch()).thenReturn(new int[] { 0 });
-		Exception exception = assertThrows(EmptyResultDataAccessException.class, () -> writer.write(List.of("bar")));
+		Exception exception = assertThrows(EmptyResultDataAccessException.class, () -> writer.write(Chunk.of("bar")));
 		String message = exception.getMessage();
 		assertTrue(message.contains("did not update"), "Wrong message: " + message);
 		assertEquals(2, list.size());
@@ -133,7 +136,7 @@ class JdbcBatchItemWriterClassicTests {
 		});
 		ps.addBatch();
 		when(ps.executeBatch()).thenReturn(new int[] { 123 });
-		Exception exception = assertThrows(RuntimeException.class, () -> writer.write(List.of("foo")));
+		Exception exception = assertThrows(RuntimeException.class, () -> writer.write(Chunk.of("foo")));
 		assertEquals("bar", exception.getMessage());
 		assertEquals(2, list.size());
 		writer.setItemPreparedStatementSetter(new ItemPreparedStatementSetter<String>() {
@@ -142,7 +145,7 @@ class JdbcBatchItemWriterClassicTests {
 				list.add(item);
 			}
 		});
-		writer.write(Collections.singletonList("foo"));
+		writer.write(Chunk.of("foo"));
 		assertEquals(4, list.size());
 		assertTrue(list.contains("SQL"));
 		assertTrue(list.contains("foo"));

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/database/JdbcBatchItemWriterNamedParameterTests.java

@@ -24,6 +24,7 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.mockito.ArgumentCaptor;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.dao.EmptyResultDataAccessException;
 import org.springframework.jdbc.core.namedparam.BeanPropertySqlParameterSource;
 import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
@@ -43,6 +44,7 @@ import static org.mockito.hamcrest.MockitoHamcrest.argThat;
  * @author Thomas Risberg
  * @author Will Schipp
  * @author Michael Minella
+ * @author Mahmoud Ben Hassine
  */
 public class JdbcBatchItemWriterNamedParameterTests {
 
@@ -119,7 +121,7 @@ public class JdbcBatchItemWriterNamedParameterTests {
 				eqSqlParameterSourceArray(
 						new SqlParameterSource[] { new BeanPropertySqlParameterSource(new Foo("bar")) })))
 				.thenReturn(new int[] { 1 });
-		writer.write(List.of(new Foo("bar")));
+		writer.write(Chunk.of(new Foo("bar")));
 	}
 
 	@SuppressWarnings({ "rawtypes", "unchecked" })
@@ -134,7 +136,7 @@ public class JdbcBatchItemWriterNamedParameterTests {
 		ArgumentCaptor<Map[]> captor = ArgumentCaptor.forClass(Map[].class);
 
 		when(namedParameterJdbcOperations.batchUpdate(eq(sql), captor.capture())).thenReturn(new int[] { 1 });
-		mapWriter.write(List.of(Map.of("foo", "bar")));
+		mapWriter.write(Chunk.of(Map.of("foo", "bar")));
 
 		assertEquals(1, captor.getValue().length);
 		Map<String, Object> results = captor.getValue()[0];
@@ -158,7 +160,7 @@ public class JdbcBatchItemWriterNamedParameterTests {
 		ArgumentCaptor<SqlParameterSource[]> captor = ArgumentCaptor.forClass(SqlParameterSource[].class);
 
 		when(namedParameterJdbcOperations.batchUpdate(any(String.class), captor.capture())).thenReturn(new int[] { 1 });
-		mapWriter.write(List.of(Map.of("foo", "bar")));
+		mapWriter.write(Chunk.of(Map.of("foo", "bar")));
 
 		assertEquals(1, captor.getValue().length);
 		SqlParameterSource results = captor.getValue()[0];
@@ -172,7 +174,7 @@ public class JdbcBatchItemWriterNamedParameterTests {
 						new SqlParameterSource[] { new BeanPropertySqlParameterSource(new Foo("bar")) })))
 				.thenReturn(new int[] { 0 });
 		Exception exception = assertThrows(EmptyResultDataAccessException.class,
-				() -> writer.write(List.of(new Foo("bar"))));
+				() -> writer.write(Chunk.of(new Foo("bar"))));
 		String message = exception.getMessage();
 		assertTrue(message.contains("did not update"), "Wrong message: " + message);
 	}
@@ -184,7 +186,7 @@ public class JdbcBatchItemWriterNamedParameterTests {
 				eqSqlParameterSourceArray(
 						new SqlParameterSource[] { new BeanPropertySqlParameterSource(new Foo("bar")) })))
 				.thenThrow(ex);
-		Exception exception = assertThrows(RuntimeException.class, () -> writer.write(List.of(new Foo("bar"))));
+		Exception exception = assertThrows(RuntimeException.class, () -> writer.write(Chunk.of(new Foo("bar"))));
 		assertEquals("ERROR", exception.getMessage());
 	}
 

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/database/JpaItemWriterIntegrationTests.java

@@ -24,6 +24,7 @@ import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.sample.Person;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Bean;
@@ -71,7 +72,7 @@ class JpaItemWriterIntegrationTests {
 		JpaItemWriter<Person> writer = new JpaItemWriter<>();
 		writer.setEntityManagerFactory(this.entityManagerFactory);
 		writer.afterPropertiesSet();
-		List<Person> items = Arrays.asList(new Person(1, "foo"), new Person(2, "bar"));
+		Chunk<Person> items = Chunk.of(new Person(1, "foo"), new Person(2, "bar"));
 
 		// when
 		writer.write(items);
@@ -87,7 +88,7 @@ class JpaItemWriterIntegrationTests {
 		writer.setEntityManagerFactory(this.entityManagerFactory);
 		writer.setUsePersist(true);
 		writer.afterPropertiesSet();
-		List<Person> items = Arrays.asList(new Person(1, "foo"), new Person(2, "bar"));
+		Chunk<Person> items = Chunk.of(new Person(1, "foo"), new Person(2, "bar"));
 
 		// when
 		writer.write(items);