OPEN - issue BATCH-159: JobExecutor should return a JobExecution (which itself contains the ExitStatus)

http://opensource.atlassian.com/projects/spring/browse/BATCH-159

Add listeners to JobExecutionFacade

execution/src/main/java/org/springframework/batch/execution/facade/JobExecutionListenerSupport.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2006-2007 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.execution.facade;
+
+import org.springframework.batch.core.domain.JobExecution;
+
+/**
+ * Simple no-op implementation of {@link JobExecutionListener} which does
+ * nothing.
+ * 
+ * @author Dave Syer
+ * 
+ */
+public class JobExecutionListenerSupport implements JobExecutionListener {
+
+	/**
+	 * No-op for subclasses to extend.
+	 * 
+	 * @see org.springframework.batch.execution.facade.JobExecutionListener#after(org.springframework.batch.core.domain.JobExecution)
+	 */
+	public void after(JobExecution execution) {
+		// no-op
+	}
+
+	/**
+	 * No-op for subclasses to extend.
+	 * 
+	 * @see org.springframework.batch.execution.facade.JobExecutionListener#before(org.springframework.batch.core.domain.JobExecution)
+	 */
+	public void before(JobExecution execution) {
+		// no-op
+	}
+
+}

execution/src/main/java/org/springframework/batch/execution/facade/SimpleJobExecutorFacade.java

@@ -16,7 +16,10 @@
 
 package org.springframework.batch.execution.facade;
 
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Iterator;
+import java.util.List;
 import java.util.Properties;
 
 import org.springframework.batch.core.configuration.JobConfiguration;
@@ -64,6 +67,18 @@ public class SimpleJobExecutorFacade implements JobExecutorFacade,
 
 	private Object mutex = new Object();
 
+	private List listeners = new ArrayList();
+
+	/**
+	 * Public setter for the listeners property.
+	 * 
+	 * @param listeners
+	 *            the listeners to set - a list of {@link JobExecutionListener}.
+	 */
+	public void setJobExecutionListeners(List listeners) {
+		this.listeners = listeners;
+	}
+
 	/**
 	 * Public accessor for the running property.
 	 * 
@@ -158,7 +173,9 @@ public class SimpleJobExecutorFacade implements JobExecutorFacade,
 	}
 
 	/**
-	 * Internal accounting for the job execution. Callback at start of job.
+	 * Internal accounting for the job execution. Callback at start of job,
+	 * dealing with internal housekeeping before delegating to listeners in the
+	 * order that they were given.
 	 * 
 	 * @param execution
 	 */
@@ -166,14 +183,28 @@ public class SimpleJobExecutorFacade implements JobExecutorFacade,
 		synchronized (mutex) {
 			running++;
 		}
+		for (Iterator iterator = listeners.iterator(); iterator.hasNext();) {
+			JobExecutionListener listener = (JobExecutionListener) iterator
+					.next();
+			listener.before(execution);
+		}
 	}
 
 	/**
-	 * Internal accounting for the job execution. Callback at end of job.
+	 * Internal accounting for the job execution. Callback at end of job
+	 * delegating first to listeners, in reverse order to the list supplied, and
+	 * then finally dealing with internal housekeeping.
 	 * 
 	 * @param execution
 	 */
 	public void after(JobExecution execution) {
+		ArrayList reversed = new ArrayList(listeners);
+		Collections.reverse(reversed);
+		for (Iterator iterator = reversed.iterator(); iterator.hasNext();) {
+			JobExecutionListener listener = (JobExecutionListener) iterator
+					.next();
+			listener.after(execution);
+		}
 		synchronized (mutex) {
 			// assume execution is synchronous so when we get to here we are
 			// not running any more

execution/src/main/java/org/springframework/batch/execution/step/simple/SimpleStepExecutor.java

@@ -77,11 +77,6 @@ public class SimpleStepExecutor implements StepExecutor {
 	 */
 	private static final String STEP_EXECUTION_KEY = "STEP_EXECUTION";
 
-	/**
-	 * Attribute key for statistics instance in step context.
-	 */
-	public static final String STATISTICS_KEY = "STATISTICS";
-
 	private RepeatOperations chunkOperations = new RepeatTemplate();
 
 	private RepeatOperations stepOperations = new RepeatTemplate();
@@ -239,8 +234,6 @@ public class SimpleStepExecutor implements StepExecutor {
 									}
 									Properties statistics = getStatistics(module);
 									stepExecution.setStatistics(statistics);
-									context.setAttribute(STATISTICS_KEY,
-											statistics);
 									stepExecution.incrementCommitCount();
 									jobRepository.saveOrUpdate(stepExecution);
 									return result;