IN PROGRESS - BATCH-711: Upgrade ItemWriter and implementations to use parameterized types

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

@@ -26,7 +26,7 @@ import org.springframework.batch.item.transform.ItemTransformer;
  * @author Dave Syer
  * 
  */
-public class LineAggregatorItemTransformer implements ItemTransformer {
+public class LineAggregatorItemTransformer<T> implements ItemTransformer<T, String> {
 
 	private LineAggregator aggregator = new DelimitedLineAggregator();
 
@@ -44,7 +44,7 @@ public class LineAggregatorItemTransformer implements ItemTransformer {
 	 * 
 	 * @see org.springframework.batch.item.transform.ItemTransformer#transform(java.lang.Object)
 	 */
-	public Object transform(Object item) throws Exception {
+	public String transform(T item) throws Exception {
 		return aggregator.aggregate(createFieldSet(item));
 	}
 
@@ -58,7 +58,7 @@ public class LineAggregatorItemTransformer implements ItemTransformer {
 	 * 
 	 * @throws ConversionException if the field set cannot be created
 	 */
-	protected FieldSet createFieldSet(Object item) throws ConversionException {
+	protected FieldSet createFieldSet(T item) throws ConversionException {
 		try {
 			return new DefaultFieldSet((String[]) item);
 		}

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

@@ -15,6 +15,7 @@ import org.springframework.batch.item.transform.ItemTransformer;
  * @author Dave Syer
  * 
  */
+@SuppressWarnings("unchecked")
 public class RecursiveCollectionItemTransformer implements ItemTransformer {
 
 	private static final String LINE_SEPARATOR = System.getProperty("line.separator");

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

@@ -11,18 +11,22 @@ import org.springframework.util.Assert;
  * injected <code>ItemTransformer</code>s (return value of previous
  * transformation is the entry value of the next).
  * 
+ * Note the user is responsible for injecting a chain of {@link ItemTransformer}
+ * s that conforms to declared input and output types.
+ * 
  * @author Robert Kasanicky
  */
-public class CompositeItemTransformer implements ItemTransformer, InitializingBean {
+@SuppressWarnings("unchecked")
+public class CompositeItemTransformer<I, O> implements ItemTransformer<I, O>, InitializingBean {
 
 	private List<ItemTransformer> itemTransformers;
 
-	public Object transform(Object item) throws Exception {
+	public O transform(I item) throws Exception {
 		Object result = item;
 		for (Iterator<ItemTransformer> iterator = itemTransformers.listIterator(); iterator.hasNext();) {
 			result = iterator.next().transform(result);
 		}
-		return result;
+		return (O) result;
 	}
 
 	public void afterPropertiesSet() throws Exception {