BATCH-919: reuse ChunkProcessor in integration

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

@@ -15,6 +15,8 @@
  */
 package org.springframework.batch.core;
 
+import java.io.Serializable;
+
 /**
  * Represents a contribution to a {@link StepExecution}, buffering changes until
  * they can be applied at a chunk boundary.
@@ -22,7 +24,7 @@ package org.springframework.batch.core;
  * @author Dave Syer
  * 
  */
-public class StepContribution {
+public class StepContribution implements Serializable {
 
 	private volatile int readCount = 0;
 

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

@@ -1,6 +1,7 @@
 package org.springframework.batch.core.step.item;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
@@ -15,7 +16,7 @@ import java.util.List;
  * @author Dave Syer
  * 
  */
-class Chunk<W> implements Iterable<W> {
+public class Chunk<W> implements Iterable<W> {
 
 	private List<W> items = new ArrayList<W>();
 
@@ -30,8 +31,12 @@ class Chunk<W> implements Iterable<W> {
 	public Chunk() {
 		this(null,null);
 	}
+
+	public Chunk(Collection<? extends W> items) {
+		this(items,null);
+	}
 	
-	public Chunk(List<W> items, List<SkipWrapper<W>> skips) {
+	public Chunk(Collection<? extends W> items, List<SkipWrapper<W>> skips) {
 		super();
 		if (items!=null) {
 			this.items = new ArrayList<W>(items);

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

@@ -8,20 +8,55 @@ import org.springframework.batch.core.listener.MulticasterBatchListener;
 import org.springframework.batch.core.step.skip.SkipListenerFailedException;
 import org.springframework.batch.item.ItemProcessor;
 import org.springframework.batch.item.ItemWriter;
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.util.Assert;
 
-public class SimpleChunkProcessor<I, O> implements ChunkProcessor<I> {
+public class SimpleChunkProcessor<I, O> implements ChunkProcessor<I>, InitializingBean {
 
-	private final ItemProcessor<? super I, ? extends O> itemProcessor;
+	private ItemProcessor<? super I, ? extends O> itemProcessor;
 
-	private final ItemWriter<? super O> itemWriter;
+	private ItemWriter<? super O> itemWriter;
 
 	private final MulticasterBatchListener<I, O> listener = new MulticasterBatchListener<I, O>();
 
+	/**
+	 * Default constructor for ease of configuration (both itemWriter and
+	 * itemProcessor are mandatory).
+	 */
+	@SuppressWarnings("unused")
+	private SimpleChunkProcessor() {
+		this(null, null);
+	}
+
 	public SimpleChunkProcessor(ItemProcessor<? super I, ? extends O> itemProcessor, ItemWriter<? super O> itemWriter) {
 		this.itemProcessor = itemProcessor;
 		this.itemWriter = itemWriter;
 	}
 
+	/**
+	 * @param itemProcessor the {@link ItemProcessor} to set
+	 */
+	public void setItemProcessor(ItemProcessor<? super I, ? extends O> itemProcessor) {
+		this.itemProcessor = itemProcessor;
+	}
+
+	/**
+	 * @param itemWriter the {@link ItemWriter} to set
+	 */
+	public void setItemWriter(ItemWriter<? super O> itemWriter) {
+		this.itemWriter = itemWriter;
+	}
+
+	/**
+	 * Check mandatory properties.
+	 * 
+	 * @see InitializingBean#afterPropertiesSet()
+	 */
+	public void afterPropertiesSet() throws Exception {
+		Assert.notNull(itemWriter, "ItemWriter must be set");
+		Assert.notNull(itemProcessor, "ItemProcessor must be set");
+	}
+
 	/**
 	 * Register some {@link StepListener}s with the handler. Each will get the
 	 * callbacks in the order specified at the correct stage.