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1   /*
2    * Copyright 2006-2007 the original author or authors.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package org.springframework.batch.sample.jmx;
18  
19  import javax.management.Notification;
20  
21  import org.apache.commons.logging.Log;
22  import org.apache.commons.logging.LogFactory;
23  import org.springframework.context.ApplicationEvent;
24  import org.springframework.context.ApplicationListener;
25  import org.springframework.jmx.export.notification.NotificationPublisher;
26  import org.springframework.jmx.export.notification.NotificationPublisherAware;
27  
28  /**
29   * JMX notification broadcaster
30   * 
31   * @author Dave Syer
32   * @since 1.0
33   */
34  public class JobExecutionNotificationPublisher implements ApplicationListener, NotificationPublisherAware {
35  
36  	protected static final Log logger = LogFactory.getLog(JobExecutionNotificationPublisher.class);
37  
38  	private NotificationPublisher notificationPublisher;
39  
40  	private int notificationCount = 0;
41  
42  	/**
43  	 * Injection setter.
44  	 * 
45  	 * @see org.springframework.jmx.export.notification.NotificationPublisherAware#setNotificationPublisher(org.springframework.jmx.export.notification.NotificationPublisher)
46  	 */
47  	public void setNotificationPublisher(NotificationPublisher notificationPublisher) {
48  		this.notificationPublisher = notificationPublisher;
49  	}
50  
51  	/**
52  	 * If the event is a {@link SimpleMessageApplicationEvent} for open and
53  	 * close we log the event at INFO level and send a JMX notification if we
54  	 * are also an MBean.
55  	 * 
56  	 * @see ApplicationListener#onApplicationEvent(ApplicationEvent) 
57  	 */
58  	public void onApplicationEvent(ApplicationEvent applicationEvent) {
59  		if (applicationEvent instanceof SimpleMessageApplicationEvent) {
60  			String message = applicationEvent.toString();
61  			logger.info(message);
62  			publish(message);
63  		}
64  	}
65  
66  	/**
67  	 * Publish the provided message to an external listener if there is one.
68  	 * 
69  	 * @param message the message to publish
70  	 */
71  	private void publish(String message) {
72  		if (notificationPublisher != null) {
73  			Notification notification = new Notification("JobExecutionApplicationEvent", this, notificationCount++,
74  					message);
75  			/*
76  			 * We can't create a notification with a null source, but we can set
77  			 * it to null after creation(!). We want it to be null so that
78  			 * Spring will replace it automatically with the ObjectName (in
79  			 * ModelMBeanNotificationPublisher).
80  			 */
81  			notification.setSource(null);
82  			notificationPublisher.sendNotification(notification);
83  		}
84  	}
85  
86  }