OPEN - issue BATCH-771: Refactor Listeners for chunk changes

Lift Chunk up to top level and use it to manage the skip / retry logic.  Not finished.

spring-batch-infrastructure/src/main/java/org/springframework/batch/retry/RecoveryCallback.java

@@ -28,7 +28,8 @@ public interface RecoveryCallback {
 	 * @param context the current retry context
 	 * @return an Object that can be used to replace the callback result that
 	 * failed
+	 * @throws Exception 
 	 */
-	Object recover(RetryContext context);
+	Object recover(RetryContext context) throws Exception;
 
 }

spring-batch-infrastructure/src/main/java/org/springframework/batch/retry/RetryPolicy.java

@@ -16,7 +16,6 @@
 
 package org.springframework.batch.retry;
 
-
 /**
  * A {@link RetryPolicy} is responsible for allocating and managing resources
  * needed by {@link RetryOperations}. The {@link RetryPolicy} allows retry
@@ -57,8 +56,8 @@ public interface RetryPolicy {
 	RetryContext open(RetryCallback callback, RetryContext parent);
 
 	/**
-	 * @param context a retry status created by the {@link #open(RetryCallback, RetryContext)}
-	 * method of this manager.
+	 * @param context a retry status created by the
+	 * {@link #open(RetryCallback, RetryContext)} method of this manager.
 	 * @param succeeded true if the retry callback succeeded
 	 */
 	void close(RetryContext context, boolean succeeded);
@@ -81,6 +80,8 @@ public interface RetryPolicy {
 	 * @return an appropriate value possibly from the callback.
 	 * 
 	 * @throws ExhaustedRetryException if there is no recovery path.
+	 * @throws Exception in rare cases where the policy wants to propagate the
+	 * retryable exception
 	 */
-	Object handleRetryExhausted(RetryContext context) throws ExhaustedRetryException;
+	Object handleRetryExhausted(RetryContext context) throws ExhaustedRetryException, Exception;
 }

spring-batch-infrastructure/src/main/java/org/springframework/batch/retry/policy/AbstractStatefulRetryPolicy.java

@@ -57,10 +57,18 @@ public abstract class AbstractStatefulRetryPolicy implements RetryPolicy {
 
 	/**
 	 * Return null. Subclasses should provide a recovery path if possible.
+	 * Subclasses are also encouraged not to declare throws Exception if they
+	 * can (e.g. in the plausible and common case that the recovery is a last
+	 * ditch effort to prevent a message going back to the middleware, for
+	 * instance). Any subclass that actually does throw an Exception of any type
+	 * should be aware that it will simply be propagated and the caller will
+	 * have top deal with it.
+	 * 
+	 * @throws Exception if the recovery path demands it
 	 * 
 	 * @see org.springframework.batch.retry.RetryPolicy#handleRetryExhausted(org.springframework.batch.retry.RetryContext)
 	 */
-	public Object handleRetryExhausted(RetryContext context) throws ExhaustedRetryException {
+	public Object handleRetryExhausted(RetryContext context) throws ExhaustedRetryException, Exception {
 		return null;
 	}
 

spring-batch-infrastructure/src/main/java/org/springframework/batch/retry/policy/RecoveryCallbackRetryPolicy.java

@@ -127,7 +127,7 @@ public class RecoveryCallbackRetryPolicy extends AbstractStatefulRetryPolicy {
 	 * 
 	 * @see org.springframework.batch.retry.policy.AbstractStatefulRetryPolicy#handleRetryExhausted(org.springframework.batch.retry.RetryContext)
 	 */
-	public Object handleRetryExhausted(RetryContext context) throws ExhaustedRetryException {
+	public Object handleRetryExhausted(RetryContext context) throws Exception, ExhaustedRetryException {
 		return ((RetryPolicy) context).handleRetryExhausted(context);
 	}
 
@@ -202,7 +202,7 @@ public class RecoveryCallbackRetryPolicy extends AbstractStatefulRetryPolicy {
 			throw new UnsupportedOperationException("Not supported - this code should be unreachable.");
 		}
 
-		public Object handleRetryExhausted(RetryContext context) throws ExhaustedRetryException {
+		public Object handleRetryExhausted(RetryContext context) throws Exception, ExhaustedRetryException {
 			// If there is no going back, then we can remove the history
 			retryContextCache.remove(key);
 			if (recoverer != null) {