View Javadoc

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.item.jms;
18  
19  import javax.jms.JMSException;
20  import javax.jms.Message;
21  
22  import org.springframework.batch.item.UnexpectedInputException;
23  import org.springframework.retry.interceptor.NewMethodArgumentsIdentifier;
24  
25  /**
26   * A {@link NewMethodArgumentsIdentifier} for JMS that looks for a message in
27   * the arguments and checks its delivery status.
28   * 
29   * @author Dave Syer
30   * 
31   */
32  public class JmsNewMethodArgumentsIdentifier<T> implements NewMethodArgumentsIdentifier {
33  
34  	/**
35  	 * If any of the arguments is a message, check the JMS re-delivered flag and
36  	 * return it, otherwise return false to be on the safe side.
37  	 * 
38  	 * @see org.springframework.retry.interceptor.NewMethodArgumentsIdentifier#isNew(java.lang.Object[])
39  	 */
40      @Override
41  	public boolean isNew(Object[] args) {
42  
43  		for (Object item : args) {
44  			if (item instanceof Message) {
45  				try {
46  					return !((Message) item).getJMSRedelivered();
47  				}
48  				catch (JMSException e) {
49  					throw new UnexpectedInputException("Could not extract message ID", e);
50  				}
51  			}
52  		}
53  		return false;
54  	}
55  
56  }