OPEN - issue BATCH-378: RepeatListener is confusing and too generic to use for 'intercepting' a step

http://jira.springframework.org/browse/BATCH-378

Remove unnecessary listener implementations and migrate some functionality to samples.  In the process discovered that tasklet steps cannot be stopped.

spring-batch-samples/src/main/java/org/springframework/batch/sample/advice/JobExecutionNotificationPublisher.java

@@ -0,0 +1,87 @@
+/*
+ * 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.sample.advice;
+
+import javax.management.Notification;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.springframework.context.ApplicationEvent;
+import org.springframework.context.ApplicationListener;
+import org.springframework.jmx.export.notification.NotificationPublisher;
+import org.springframework.jmx.export.notification.NotificationPublisherAware;
+
+/**
+ * JMX notification broadcaster
+ * 
+ * @author Dave Syer
+ * @since 2.1
+ */
+public class JobExecutionNotificationPublisher implements ApplicationListener, NotificationPublisherAware {
+
+	protected static final Log logger = LogFactory.getLog(JobExecutionNotificationPublisher.class);
+
+	private NotificationPublisher notificationPublisher;
+
+	private int notificationCount = 0;
+
+	/**
+	 * Injection setter.
+	 * 
+	 * @see org.springframework.jmx.export.notification.NotificationPublisherAware#setNotificationPublisher(org.springframework.jmx.export.notification.NotificationPublisher)
+	 */
+	public void setNotificationPublisher(NotificationPublisher notificationPublisher) {
+		this.notificationPublisher = notificationPublisher;
+	}
+
+	/**
+	 * If the event is a {@link RepeatOperationsApplicationEvent} for open and
+	 * close we log the event at INFO level and send a JMX notification if we
+	 * are also an MBean.
+	 * 
+	 * @see org.springframework.batch.execution.launch.SimpleJobLauncher#onApplicationEvent(org.springframework.context.ApplicationEvent)
+	 */
+	public void onApplicationEvent(ApplicationEvent applicationEvent) {
+		if (applicationEvent instanceof SimpleMessageApplicationEvent) {
+			String message = applicationEvent.toString();
+			logger.info(message);
+			publish(message);
+		}
+		return;
+	}
+
+	/**
+	 * Publish the provided message to an external listener if there is one.
+	 * 
+	 * @param message the message to publish
+	 */
+	private void publish(String message) {
+		if (notificationPublisher != null) {
+			Notification notification = new Notification("JobExecutionApplicationEvent", this, notificationCount++,
+					message);
+			/*
+			 * We can't create a notification with a null source, but we can set
+			 * it to null after creation(!). We want it to be null so that
+			 * Spring will replace it automatically with the ObjectName (in
+			 * ModelMBeanNotificationPublisher).
+			 */
+			notification.setSource(null);
+			notificationPublisher.sendNotification(notification);
+		}
+	}
+
+}

spring-batch-samples/src/main/java/org/springframework/batch/sample/advice/MethodExecutionApplicationEventAdvice.java

@@ -0,0 +1,68 @@
+/*
+ * 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.sample.advice;
+
+import org.aspectj.lang.JoinPoint;
+import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.context.ApplicationEventPublisherAware;
+
+/**
+ * Wraps calls for 'Processing' methods which output a single Object to write
+ * the string representation of the object to the log.
+ * 
+ * @author Lucas Ward
+ */
+public class MethodExecutionApplicationEventAdvice implements ApplicationEventPublisherAware {
+
+	private ApplicationEventPublisher applicationEventPublisher;
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.context.ApplicationEventPublisherAware#setApplicationEventPublisher(org.springframework.context.ApplicationEventPublisher)
+	 */
+	public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
+		this.applicationEventPublisher = applicationEventPublisher;
+	}
+
+	public void before(JoinPoint jp) {
+		String msg = "Before: "+jp.toShortString();
+		publish(jp.getTarget(), msg);
+	}
+
+	public void after(JoinPoint jp) {
+		String msg = "After: "+jp.toShortString();
+		publish(jp.getTarget(), msg);
+	}
+
+	public void onError(JoinPoint jp, Throwable t) {
+		String msg = "Error in: "+jp.toShortString()+"("+t.getClass()+":"+t.getMessage()+")";
+		publish(jp.getTarget(), msg);
+	}
+	
+	/**
+	 * Publish a {@link RepeatOperationsApplicationEvent} with the given
+	 * parameters.
+	 * 
+	 * @param context the current batch context
+	 * @param message the message to publish
+	 * @param type the type of event to publish
+	 */
+	private void publish(Object source, String message) {
+		applicationEventPublisher.publishEvent(new SimpleMessageApplicationEvent(source, message));
+	}
+
+}

spring-batch-samples/src/main/java/org/springframework/batch/sample/advice/SimpleMessageApplicationEvent.java

@@ -0,0 +1,29 @@
+package org.springframework.batch.sample.advice;
+
+import org.springframework.context.ApplicationEvent;
+
+/**
+ * @author Dave Syer
+ * 
+ */
+public class SimpleMessageApplicationEvent extends ApplicationEvent {
+
+	private String message;
+
+	/**
+	 * @param source
+	 * @param message
+	 */
+	public SimpleMessageApplicationEvent(Object source, String message) {
+		super(source);
+		this.message = message;
+	}
+	
+	/* (non-Javadoc)
+	 * @see java.util.EventObject#toString()
+	 */
+	public String toString() {
+		return "message=["+message+"], " + super.toString();
+	}
+
+}

spring-batch-samples/src/main/java/org/springframework/batch/sample/tasklet/InfiniteLoopTasklet.java

@@ -16,6 +16,8 @@
 
 package org.springframework.batch.sample.tasklet;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.springframework.batch.core.tasklet.Tasklet;
 import org.springframework.batch.repeat.ExitStatus;
 
@@ -30,6 +32,7 @@ import org.springframework.batch.repeat.ExitStatus;
 public class InfiniteLoopTasklet implements Tasklet {
 
 	private int count = 0;
+	private static final Log logger = LogFactory.getLog(InfiniteLoopTasklet.class);
 
 	/**
 	 * 
@@ -39,9 +42,16 @@ public class InfiniteLoopTasklet implements Tasklet {
 	}
 
 	public ExitStatus execute() throws Exception {
-		Thread.sleep(500);
-		count++;
-		return ExitStatus.CONTINUABLE;
+		while(true) {
+			try {
+				Thread.sleep(500);
+			} catch (InterruptedException e) {
+				Thread.currentThread().interrupt();
+				throw new RuntimeException("Job interrupted.");
+			}
+			count++;
+			logger.info("Executing infinite loop, at count="+count);
+		}
 	}
 
 }