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-samples/src/main/java/org/springframework/batch/sample/common/InfiniteLoopWriter.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.
@@ -22,6 +22,7 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.StepExecutionListener;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 
 /**
@@ -53,7 +54,7 @@ public class InfiniteLoopWriter implements StepExecutionListener, ItemWriter<Obj
 	}
 
 	@Override
-	public void write(List<? extends Object> items) throws Exception {
+	public void write(Chunk<? extends Object> items) throws Exception {
 		try {
 			Thread.sleep(500);
 		}

spring-batch-samples/src/main/java/org/springframework/batch/sample/common/StagingItemWriter.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.
@@ -24,6 +24,7 @@ import java.util.ListIterator;
 import org.springframework.batch.core.ExitStatus;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.StepExecutionListener;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.jdbc.core.BatchPreparedStatementSetter;
 import org.springframework.jdbc.core.support.JdbcDaoSupport;
@@ -72,14 +73,14 @@ public class StagingItemWriter<T> extends JdbcDaoSupport implements StepExecutio
 	 * @see ItemWriter#write(java.util.List)
 	 */
 	@Override
-	public void write(final List<? extends T> items) {
-		final ListIterator<? extends T> itemIterator = items.listIterator();
+	public void write(final Chunk<? extends T> chunk) {
+		final ListIterator<? extends T> itemIterator = chunk.getItems().listIterator();
 
 		getJdbcTemplate().batchUpdate("INSERT into BATCH_STAGING (ID, JOB_ID, VALUE, PROCESSED) values (?,?,?,?)",
 				new BatchPreparedStatementSetter() {
 					@Override
 					public int getBatchSize() {
-						return items.size();
+						return chunk.size();
 					}
 
 					@Override

spring-batch-samples/src/main/java/org/springframework/batch/sample/domain/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.
@@ -18,6 +18,7 @@ package org.springframework.batch.sample.domain.football.internal;
 
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.sample.domain.football.Game;
 import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
@@ -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-samples/src/main/java/org/springframework/batch/sample/domain/football/internal/JdbcPlayerSummaryDao.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2012 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 javax.sql.DataSource;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.sample.domain.football.PlayerSummary;
 import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
@@ -36,7 +37,7 @@ public class JdbcPlayerSummaryDao implements ItemWriter<PlayerSummary> {
 	private NamedParameterJdbcOperations namedParameterJdbcTemplate;
 
 	@Override
-	public void write(List<? extends PlayerSummary> summaries) {
+	public void write(Chunk<? extends PlayerSummary> summaries) {
 
 		for (PlayerSummary summary : summaries) {
 

spring-batch-samples/src/main/java/org/springframework/batch/sample/domain/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.
@@ -18,6 +18,7 @@ package org.springframework.batch.sample.domain.football.internal;
 
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.sample.domain.football.Player;
 import org.springframework.batch.sample.domain.football.PlayerDao;
@@ -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-samples/src/main/java/org/springframework/batch/sample/domain/person/internal/PersonWriter.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.
@@ -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.sample.domain.person.Person;
 
@@ -28,7 +30,7 @@ public class PersonWriter implements ItemWriter<Person> {
 	private static Log log = LogFactory.getLog(PersonWriter.class);
 
 	@Override
-	public void write(List<? extends Person> data) {
+	public void write(Chunk<? extends Person> data) {
 		if (log.isDebugEnabled()) {
 			log.debug("Processing: " + data);
 		}

spring-batch-samples/src/main/java/org/springframework/batch/sample/domain/trade/CustomerUpdateWriter.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.
@@ -18,10 +18,12 @@ package org.springframework.batch.sample.domain.trade;
 
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 
 /**
  * @author Lucas Ward
+ * @author Mahmoud Ben Hassine
  *
  */
 public class CustomerUpdateWriter implements ItemWriter<CustomerUpdate> {
@@ -29,7 +31,7 @@ public class CustomerUpdateWriter implements ItemWriter<CustomerUpdate> {
 	private CustomerDao customerDao;
 
 	@Override
-	public void write(List<? extends CustomerUpdate> items) throws Exception {
+	public void write(Chunk<? extends CustomerUpdate> items) throws Exception {
 		for (CustomerUpdate customerUpdate : items) {
 			if (customerUpdate.getOperation() == CustomerOperation.ADD) {
 				customerDao.insertCustomer(customerUpdate.getCustomerName(), customerUpdate.getCredit());

spring-batch-samples/src/main/java/org/springframework/batch/sample/domain/trade/internal/CustomerCreditItemWriter.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 +18,7 @@ package org.springframework.batch.sample.domain.trade.internal;
 
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.sample.domain.trade.CustomerCredit;
 import org.springframework.batch.sample.domain.trade.CustomerCreditDao;
@@ -26,6 +27,7 @@ import org.springframework.batch.sample.domain.trade.CustomerCreditDao;
  * Delegates actual writing to a custom DAO.
  *
  * @author Robert Kasanicky
+ * @author Mahmoud Ben Hassine
  */
 public class CustomerCreditItemWriter implements ItemWriter<CustomerCredit> {
 
@@ -40,7 +42,7 @@ public class CustomerCreditItemWriter implements ItemWriter<CustomerCredit> {
 	}
 
 	@Override
-	public void write(List<? extends CustomerCredit> customerCredits) throws Exception {
+	public void write(Chunk<? extends CustomerCredit> customerCredits) throws Exception {
 		for (CustomerCredit customerCredit : customerCredits) {
 			customerCreditDao.writeCredit(customerCredit);
 		}

spring-batch-samples/src/main/java/org/springframework/batch/sample/domain/trade/internal/CustomerCreditUpdateWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2014 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.sample.domain.trade.internal;
 
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.sample.domain.trade.CustomerCredit;
 import org.springframework.batch.sample.domain.trade.CustomerCreditDao;
@@ -29,7 +30,7 @@ public class CustomerCreditUpdateWriter implements ItemWriter<CustomerCredit> {
 	private CustomerCreditDao dao;
 
 	@Override
-	public void write(List<? extends CustomerCredit> customerCredits) throws Exception {
+	public void write(Chunk<? extends CustomerCredit> customerCredits) throws Exception {
 		for (CustomerCredit customerCredit : customerCredits) {
 			if (customerCredit.getCredit().doubleValue() > creditFilter) {
 				dao.writeCredit(customerCredit);

spring-batch-samples/src/main/java/org/springframework/batch/sample/domain/trade/internal/CustomerUpdateWriter.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 +18,7 @@ package org.springframework.batch.sample.domain.trade.internal;
 
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.sample.domain.trade.CustomerDebit;
 import org.springframework.batch.sample.domain.trade.CustomerDebitDao;
@@ -27,13 +28,14 @@ import org.springframework.batch.sample.domain.trade.Trade;
  * Transforms Trade to a CustomerDebit and asks DAO delegate to write the result.
  *
  * @author Robert Kasanicky
+ * @author Mahmoud Ben Hassine
  */
 public class CustomerUpdateWriter implements ItemWriter<Trade> {
 
 	private CustomerDebitDao dao;
 
 	@Override
-	public void write(List<? extends Trade> trades) {
+	public void write(Chunk<? extends Trade> trades) {
 		for (Trade trade : trades) {
 			CustomerDebit customerDebit = new CustomerDebit();
 			customerDebit.setName(trade.getCustomer());

spring-batch-samples/src/main/java/org/springframework/batch/sample/domain/trade/internal/FlatFileCustomerCreditDao.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 +18,7 @@ package org.springframework.batch.sample.domain.trade.internal;
 
 import java.util.Collections;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.ItemStream;
 import org.springframework.batch.item.ItemWriter;
@@ -30,6 +31,7 @@ import org.springframework.beans.factory.DisposableBean;
  *
  * @see CustomerCreditDao
  * @author Robert Kasanicky
+ * @author Mahmoud Ben Hassine
  */
 public class FlatFileCustomerCreditDao implements CustomerCreditDao, DisposableBean {
 
@@ -48,7 +50,7 @@ public class FlatFileCustomerCreditDao implements CustomerCreditDao, DisposableB
 
 		String line = "" + customerCredit.getName() + separator + customerCredit.getCredit();
 
-		itemWriter.write(Collections.singletonList(line));
+		itemWriter.write(Chunk.of(line));
 	}
 
 	public void setSeparator(String separator) {

spring-batch-samples/src/main/java/org/springframework/batch/sample/domain/trade/internal/HibernateAwareCustomerCreditItemWriter.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 +19,8 @@ package org.springframework.batch.sample.domain.trade.internal;
 import java.util.List;
 
 import org.hibernate.SessionFactory;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.sample.domain.trade.CustomerCredit;
 import org.springframework.batch.sample.domain.trade.CustomerCreditDao;
@@ -31,6 +33,7 @@ import org.springframework.util.Assert;
  *
  * @author Robert Kasanicky
  * @author Michael Minella
+ * @author Mahmoud Ben Hassine
  */
 public class HibernateAwareCustomerCreditItemWriter implements ItemWriter<CustomerCredit>, InitializingBean {
 
@@ -39,7 +42,7 @@ public class HibernateAwareCustomerCreditItemWriter implements ItemWriter<Custom
 	private SessionFactory sessionFactory;
 
 	@Override
-	public void write(List<? extends CustomerCredit> items) throws Exception {
+	public void write(Chunk<? extends CustomerCredit> items) throws Exception {
 		for (CustomerCredit credit : items) {
 			dao.writeCredit(credit);
 		}

spring-batch-samples/src/main/java/org/springframework/batch/sample/domain/trade/internal/TradeWriter.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 java.util.List;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.springframework.batch.core.annotation.AfterWrite;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.ItemStreamSupport;
 import org.springframework.batch.item.ItemWriter;
@@ -48,7 +49,7 @@ public class TradeWriter extends ItemStreamSupport implements ItemWriter<Trade>
 	private BigDecimal totalPrice = BigDecimal.ZERO;
 
 	@Override
-	public void write(List<? extends Trade> trades) {
+	public void write(Chunk<? extends Trade> trades) {
 
 		for (Trade trade : trades) {
 
@@ -67,7 +68,7 @@ public class TradeWriter extends ItemStreamSupport implements ItemWriter<Trade>
 	}
 
 	@AfterWrite
-	public void updateTotalPrice(List<Trade> trades) {
+	public void updateTotalPrice(Chunk<Trade> trades) {
 		for (Trade trade : trades) {
 			this.totalPrice = this.totalPrice.add(trade.getPrice());
 		}

spring-batch-samples/src/main/java/org/springframework/batch/sample/support/DummyItemWriter.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.
@@ -17,16 +17,18 @@ package org.springframework.batch.sample.support;
 
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 
 /**
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  *
  */
 public class DummyItemWriter implements ItemWriter<Object> {
 
 	@Override
-	public void write(List<? extends Object> item) throws Exception {
+	public void write(Chunk<? extends Object> item) throws Exception {
 		// NO-OP
 		Thread.sleep(500);
 	}

spring-batch-samples/src/main/java/org/springframework/batch/sample/support/RetrySampleItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2014 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.
@@ -18,19 +18,21 @@ package org.springframework.batch.sample.support;
 
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 
 /**
  * Simulates temporary output trouble - requires to retry 3 times to pass successfully.
  *
  * @author Robert Kasanicky
+ * @author Mahmoud Ben Hassine
  */
 public class RetrySampleItemWriter<T> implements ItemWriter<T> {
 
 	private int counter = 0;
 
 	@Override
-	public void write(List<? extends T> items) throws Exception {
+	public void write(Chunk<? extends T> items) throws Exception {
 		int current = counter;
 		counter += items.size();
 		if (current < 3 && (counter >= 2 || counter >= 3)) {
@@ -39,7 +41,7 @@ public class RetrySampleItemWriter<T> implements ItemWriter<T> {
 	}
 
 	/**
-	 * @return number of times {@link #write(List)} method was called.
+	 * @return number of times {@link #write(Chunk)} method was called.
 	 */
 	public int getCounter() {
 		return counter;

spring-batch-samples/src/test/java/org/springframework/batch/sample/RestartFileSampleFunctionalTests.java

@@ -24,6 +24,7 @@ import org.junit.jupiter.api.Test;
 import org.springframework.batch.core.BatchStatus;
 import org.springframework.batch.core.JobExecution;
 import org.springframework.batch.core.JobParameters;
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.file.FlatFileItemWriter;
 import org.springframework.batch.sample.domain.trade.CustomerCredit;
 import org.springframework.batch.test.AssertFile;
@@ -34,6 +35,7 @@ import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
 
 /**
  * @author Dan Garrette
+ * @author Mahmoud Ben Hassine
  * @since 2.0
  */
 @SpringJUnitConfig(
@@ -64,7 +66,7 @@ class RestartFileSampleFunctionalTests {
 		private boolean failed = false;
 
 		@Override
-		public void write(List<? extends CustomerCredit> arg0) throws Exception {
+		public void write(Chunk<? extends CustomerCredit> arg0) throws Exception {
 			for (CustomerCredit cc : arg0) {
 				if (!failed && cc.getName().equals("customer13")) {
 					failed = true;

spring-batch-samples/src/test/java/org/springframework/batch/sample/common/CustomItemWriterTests.java

@@ -22,6 +22,8 @@ import java.util.Collections;
 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.support.transaction.TransactionAwareProxyFactory;
 
@@ -31,6 +33,7 @@ import org.springframework.batch.support.transaction.TransactionAwareProxyFactor
  * code base shifts.
  *
  * @author Lucas Ward
+ * @author Mahmoud Ben Hassine
  *
  */
 class CustomItemWriterTests {
@@ -38,9 +41,9 @@ class CustomItemWriterTests {
 	@Test
 	void testFlush() throws Exception {
 		CustomItemWriter<String> itemWriter = new CustomItemWriter<>();
-		itemWriter.write(Collections.singletonList("1"));
+		itemWriter.write(Chunk.of("1"));
 		assertEquals(1, itemWriter.getOutput().size());
-		itemWriter.write(Arrays.asList("2", "3"));
+		itemWriter.write(Chunk.of("2", "3"));
 		assertEquals(3, itemWriter.getOutput().size());
 	}
 
@@ -49,8 +52,8 @@ class CustomItemWriterTests {
 		private List<T> output = TransactionAwareProxyFactory.createTransactionalList();
 
 		@Override
-		public void write(List<? extends T> items) throws Exception {
-			output.addAll(items);
+		public void write(Chunk<? extends T> chunk) throws Exception {
+			output.addAll(chunk.getItems());
 		}
 
 		public List<T> getOutput() {

spring-batch-samples/src/test/java/org/springframework/batch/sample/common/StagingItemReaderTests.java

@@ -27,6 +27,7 @@ import org.springframework.batch.core.JobExecution;
 import org.springframework.batch.core.JobInstance;
 import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.StepExecution;
+import org.springframework.batch.item.Chunk;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
@@ -66,7 +67,7 @@ class StagingItemReaderTests {
 		StepExecution stepExecution = new StepExecution("stepName",
 				new JobExecution(new JobInstance(jobId, "testJob"), new JobParameters()));
 		writer.beforeStep(stepExecution);
-		writer.write(Arrays.asList("FOO", "BAR", "SPAM", "BUCKET"));
+		writer.write(Chunk.of("FOO", "BAR", "SPAM", "BUCKET"));
 		reader.beforeStep(stepExecution);
 	}
 

spring-batch-samples/src/test/java/org/springframework/batch/sample/common/StagingItemWriterTests.java

@@ -27,6 +27,7 @@ import org.springframework.batch.core.JobExecution;
 import org.springframework.batch.core.JobInstance;
 import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.StepExecution;
+import org.springframework.batch.item.Chunk;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
@@ -57,7 +58,7 @@ class StagingItemWriterTests {
 	@Test
 	void testProcessInsertsNewItem() {
 		int before = JdbcTestUtils.countRowsInTable(jdbcTemplate, "BATCH_STAGING");
-		writer.write(Collections.singletonList("FOO"));
+		writer.write(Chunk.of("FOO"));
 		int after = JdbcTestUtils.countRowsInTable(jdbcTemplate, "BATCH_STAGING");
 		assertEquals(before + 1, after);
 	}

spring-batch-samples/src/test/java/org/springframework/batch/sample/domain/football/internal/JdbcGameDaoIntegrationTests.java

@@ -26,6 +26,7 @@ import javax.sql.DataSource;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.sample.domain.football.Game;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.jdbc.core.JdbcOperations;
@@ -36,6 +37,7 @@ import org.springframework.transaction.annotation.Transactional;
 
 /**
  * @author Lucas Ward
+ * @author Mahmoud Ben Hassine
  *
  */
 @SpringJUnitConfig(locations = { "/data-source-context.xml" })
@@ -77,7 +79,7 @@ class JdbcGameDaoIntegrationTests {
 	@Transactional
 	@Test
 	void testWrite() {
-		gameDao.write(Collections.singletonList(game));
+		gameDao.write(Chunk.of(game));
 
 		Game tempGame = jdbcTemplate.queryForObject("SELECT * FROM GAMES where PLAYER_ID=? AND YEAR_NO=?",
 				new GameRowMapper(), "XXXXX00 ", game.getYear());

spring-batch-samples/src/test/java/org/springframework/batch/sample/domain/football/internal/JdbcPlayerSummaryDaoIntegrationTests.java

@@ -23,6 +23,8 @@ import javax.sql.DataSource;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.sample.domain.football.PlayerSummary;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.jdbc.core.JdbcTemplate;
@@ -73,7 +75,7 @@ class JdbcPlayerSummaryDaoIntegrationTests {
 	@Test
 	@Transactional
 	void testWrite() {
-		playerSummaryDao.write(Collections.singletonList(summary));
+		playerSummaryDao.write(Chunk.of(summary));
 
 		PlayerSummary testSummary = jdbcTemplate.queryForObject("SELECT * FROM PLAYER_SUMMARY",
 				new PlayerSummaryMapper());

spring-batch-samples/src/test/java/org/springframework/batch/sample/domain/trade/internal/CustomerCreditUpdateProcessorTests.java

@@ -22,6 +22,8 @@ import java.util.Collections;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.sample.domain.trade.CustomerCredit;
 import org.springframework.batch.sample.domain.trade.CustomerCreditDao;
 
@@ -47,13 +49,13 @@ class CustomerCreditUpdateProcessorTests {
 		CustomerCredit credit = new CustomerCredit();
 		credit.setCredit(new BigDecimal(CREDIT_FILTER));
 
-		writer.write(Collections.singletonList(credit));
+		writer.write(Chunk.of(credit));
 
 		credit.setCredit(new BigDecimal(CREDIT_FILTER + 1));
 
 		dao.writeCredit(credit);
 
-		writer.write(Collections.singletonList(credit));
+		writer.write(Chunk.of(credit));
 	}
 
 }

spring-batch-samples/src/test/java/org/springframework/batch/sample/domain/trade/internal/CustomerUpdateProcessorTests.java

@@ -21,6 +21,8 @@ import java.math.BigDecimal;
 import java.util.Collections;
 
 import org.junit.jupiter.api.Test;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.sample.domain.trade.CustomerDebit;
 import org.springframework.batch.sample.domain.trade.CustomerDebitDao;
 import org.springframework.batch.sample.domain.trade.Trade;
@@ -44,7 +46,7 @@ class CustomerUpdateProcessorTests {
 		CustomerUpdateWriter processor = new CustomerUpdateWriter();
 		processor.setDao(dao);
 
-		processor.write(Collections.singletonList(trade));
+		processor.write(Chunk.of(trade));
 	}
 
 }

spring-batch-samples/src/test/java/org/springframework/batch/sample/domain/trade/internal/FlatFileCustomerCreditDaoTests.java

@@ -22,6 +22,8 @@ import java.util.Collections;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.ItemStream;
 import org.springframework.batch.item.ItemWriter;
@@ -65,7 +67,7 @@ class FlatFileCustomerCreditDaoTests {
 
 		writer.setSeparator(";");
 
-		output.write(Collections.singletonList("testName;1"));
+		output.write(Chunk.of("testName;1"));
 		output.open(new ExecutionContext());
 
 		writer.writeCredit(credit);

spring-batch-samples/src/test/java/org/springframework/batch/sample/domain/trade/internal/ItemTrackingTradeItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2014 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.
@@ -21,6 +21,7 @@ import java.util.List;
 
 import javax.sql.DataSource;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.sample.domain.trade.Trade;
 import org.springframework.jdbc.core.JdbcOperations;
@@ -47,7 +48,7 @@ public class ItemTrackingTradeItemWriter implements ItemWriter<Trade> {
 	}
 
 	@Override
-	public void write(List<? extends Trade> items) throws Exception {
+	public void write(Chunk<? extends Trade> items) throws Exception {
 		List<Trade> newItems = new ArrayList<>();
 
 		for (Trade t : items) {

spring-batch-samples/src/test/java/org/springframework/batch/sample/domain/trade/internal/TradeProcessorTests.java

@@ -21,6 +21,8 @@ import java.util.Collections;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.sample.domain.trade.Trade;
 import org.springframework.batch.sample.domain.trade.TradeDao;
 
@@ -44,7 +46,7 @@ class TradeProcessorTests {
 
 		writer.writeTrade(trade);
 
-		processor.write(Collections.singletonList(trade));
+		processor.write(Chunk.of(trade));
 	}
 
 }

spring-batch-samples/src/test/java/org/springframework/batch/sample/iosample/internal/MultiLineTradeItemWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2014 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.sample.iosample.internal;
 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.ItemStream;
 import org.springframework.batch.item.ItemStreamException;
@@ -28,6 +29,7 @@ import org.springframework.batch.sample.domain.trade.Trade;
 
 /**
  * @author Dan Garrette
+ * @author Mahmoud Ben Hassine
  * @since 2.0
  */
 public class MultiLineTradeItemWriter implements ItemWriter<Trade>, ItemStream {
@@ -35,8 +37,8 @@ public class MultiLineTradeItemWriter implements ItemWriter<Trade>, ItemStream {
 	private FlatFileItemWriter<String> delegate;
 
 	@Override
-	public void write(List<? extends Trade> items) throws Exception {
-		List<String> lines = new ArrayList<>();
+	public void write(Chunk<? extends Trade> items) throws Exception {
+		Chunk<String> lines = new Chunk<>();
 
 		for (Trade t : items) {
 			lines.add("BEGIN");

spring-batch-samples/src/test/java/org/springframework/batch/sample/iosample/internal/TradeCustomerItemWriter.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.sample.iosample.internal;
 import java.math.BigDecimal;
 import java.util.List;
 
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.item.ItemWriter;
 import org.springframework.batch.sample.domain.trade.CustomerCredit;
 import org.springframework.batch.sample.domain.trade.Trade;
@@ -26,6 +27,7 @@ import org.springframework.batch.sample.domain.trade.TradeDao;
 
 /**
  * @author Dan Garrette
+ * @author Mahmoud Ben Hassine
  * @since 2.0
  */
 public class TradeCustomerItemWriter implements ItemWriter<CustomerCredit> {
@@ -35,7 +37,7 @@ public class TradeCustomerItemWriter implements ItemWriter<CustomerCredit> {
 	private int count;
 
 	@Override
-	public void write(List<? extends CustomerCredit> items) throws Exception {
+	public void write(Chunk<? extends CustomerCredit> items) throws Exception {
 		for (CustomerCredit c : items) {
 			Trade t = new Trade("ISIN" + count++, 100, new BigDecimal("1.50"), c.getName());
 			this.dao.writeTrade(t);

spring-batch-samples/src/test/java/org/springframework/batch/sample/support/ItemTrackingItemWriterTests.java

@@ -22,11 +22,14 @@ import java.io.IOException;
 import java.util.Arrays;
 
 import org.junit.jupiter.api.Test;
+
+import org.springframework.batch.item.Chunk;
 import org.springframework.batch.sample.domain.trade.Trade;
 import org.springframework.batch.sample.domain.trade.internal.ItemTrackingTradeItemWriter;
 
 /**
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  *
  */
 class ItemTrackingItemWriterTests {
@@ -39,7 +42,7 @@ class ItemTrackingItemWriterTests {
 		Trade a = new Trade("a", 0, null, null);
 		Trade b = new Trade("b", 0, null, null);
 		Trade c = new Trade("c", 0, null, null);
-		writer.write(Arrays.asList(a, b, c));
+		writer.write(Chunk.of(a, b, c));
 		assertEquals(3, writer.getItems().size());
 	}
 
@@ -49,13 +52,13 @@ class ItemTrackingItemWriterTests {
 		Trade a = new Trade("a", 0, null, null);
 		Trade b = new Trade("b", 0, null, null);
 		Trade c = new Trade("c", 0, null, null);
-		assertThrows(IOException.class, () -> writer.write(Arrays.asList(a, b, c)));
+		assertThrows(IOException.class, () -> writer.write(Chunk.of(a, b, c)));
 		assertEquals(0, writer.getItems().size());
 
 		Trade e = new Trade("e", 0, null, null);
 		Trade f = new Trade("f", 0, null, null);
 		Trade g = new Trade("g", 0, null, null);
-		writer.write(Arrays.asList(e, f, g));
+		writer.write(Chunk.of(e, f, g));
 		assertEquals(3, writer.getItems().size());
 	}
 

spring-batch-samples/src/test/java/org/springframework/batch/sample/support/RetrySampleItemWriterTests.java

@@ -23,10 +23,13 @@ import java.util.Collections;
 
 import org.junit.jupiter.api.Test;
 
+import org.springframework.batch.item.Chunk;
+
 /**
  * Tests for {@link RetrySampleItemWriter}.
  *
  * @author Robert Kasanicky
+ * @author Mahmoud Ben Hassine
  */
 class RetrySampleItemWriterTests {
 
@@ -38,11 +41,11 @@ class RetrySampleItemWriterTests {
 	@Test
 	void testProcess() throws Exception {
 		Object item = null;
-		processor.write(Collections.singletonList(item));
+		processor.write(Chunk.of(item));
 
-		assertThrows(RuntimeException.class, () -> processor.write(Arrays.asList(item, item, item)));
+		assertThrows(RuntimeException.class, () -> processor.write(Chunk.of(item, item, item)));
 
-		processor.write(Collections.singletonList(item));
+		processor.write(Chunk.of(item));
 
 		assertEquals(5, processor.getCounter());
 	}