OPEN - issue BATCH-404: FactoryBeans for step configuration

http://jira.springframework.org/browse/BATCH-404

Let the factory bean take care of chunk and item listener callbacks.  ItemOrientedStep is much simpler as a result.

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

@@ -31,6 +31,21 @@ import org.springframework.util.Assert;
 public class DelegatingItemReader extends AbstractItemReader implements Skippable, InitializingBean {
 
 	private ItemReader itemReader;
+	
+	/**
+	 * Default constructor.
+	 */
+	public DelegatingItemReader() {
+		super();
+	}
+
+	/**
+	 * Convenience constructor for setting mandatory property.
+	 */
+	public DelegatingItemReader(ItemReader itemReader) {
+		this();
+		this.itemReader = itemReader;
+	}
 
 	public void afterPropertiesSet() throws Exception {
 		Assert.notNull(itemReader, "ItemReader must not be null.");

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

@@ -16,6 +16,21 @@ public class DelegatingItemWriter implements ItemWriter, InitializingBean {
 
 	private ItemWriter writer;
 	
+	/**
+	 * Default constructor.
+	 */
+	public DelegatingItemWriter() {
+		super();
+	}
+	
+	/**
+	 * @param itemWriter
+	 */
+	public DelegatingItemWriter(ItemWriter itemWriter) {
+		this();
+		this.writer = itemWriter;
+	}
+
 	/**
 	 * Calls {@link #doProcess(Object)} and then writes the result to the
 	 * delegate {@link ItemWriter}.
@@ -23,7 +38,7 @@ public class DelegatingItemWriter implements ItemWriter, InitializingBean {
 	 * 
 	 * @see ItemWriter#process(java.lang.Object)
 	 */
-	final public void write(Object item) throws Exception {
+	public void write(Object item) throws Exception {
 		Object result = doProcess(item);
 		writer.write(result);
 	}