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1   /*
2    * Copyright 2006-2013 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  package org.springframework.batch.core.listener;
17  
18  import java.util.Iterator;
19  import java.util.List;
20  
21  import org.springframework.batch.core.ChunkListener;
22  import org.springframework.batch.core.scope.context.ChunkContext;
23  import org.springframework.core.Ordered;
24  
25  /**
26   * @author Lucas Ward
27   *
28   */
29  public class CompositeChunkListener implements ChunkListener {
30  
31  	private OrderedComposite<ChunkListener> listeners = new OrderedComposite<ChunkListener>();
32  
33  	/**
34  	 * Public setter for the listeners.
35  	 *
36  	 * @param listeners
37  	 */
38  	public void setListeners(List<? extends ChunkListener> listeners) {
39  		this.listeners.setItems(listeners);
40  	}
41  
42  	/**
43  	 * Register additional listener.
44  	 *
45  	 * @param chunkListener
46  	 */
47  	public void register(ChunkListener chunkListener) {
48  		listeners.add(chunkListener);
49  	}
50  
51  	/**
52  	 * Call the registered listeners in order, respecting and prioritizing those
53  	 * that implement {@link Ordered}.
54  	 *
55  	 * @see org.springframework.batch.core.ChunkListener#afterChunk(ChunkContext context)
56  	 */
57  	@Override
58  	public void afterChunk(ChunkContext context) {
59  		for (Iterator<ChunkListener> iterator = listeners.iterator(); iterator.hasNext();) {
60  			ChunkListener listener = iterator.next();
61  			listener.afterChunk(context);
62  		}
63  	}
64  
65  	/**
66  	 * Call the registered listeners in reverse order.
67  	 *
68  	 * @see org.springframework.batch.core.ChunkListener#beforeChunk(ChunkContext context)
69  	 */
70  	@Override
71  	public void beforeChunk(ChunkContext context) {
72  		for (Iterator<ChunkListener> iterator = listeners.reverse(); iterator.hasNext();) {
73  			ChunkListener listener = iterator.next();
74  			listener.beforeChunk(context);
75  		}
76  	}
77  
78  	@Override
79  	public void afterChunkError(ChunkContext context) {
80  		for (Iterator<ChunkListener> iterator = listeners.iterator(); iterator.hasNext();) {
81  			ChunkListener listener = iterator.next();
82  			listener.afterChunkError(context);
83  		}
84  	}
85  }