| 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 | package org.springframework.batch.item.support; |
| 17 | |
| 18 | import java.util.ArrayList; |
| 19 | import java.util.Arrays; |
| 20 | import java.util.Iterator; |
| 21 | import java.util.List; |
| 22 | |
| 23 | import org.springframework.batch.item.ExecutionContext; |
| 24 | import org.springframework.batch.item.ItemStream; |
| 25 | import org.springframework.batch.item.ItemStreamException; |
| 26 | |
| 27 | /** |
| 28 | * Simple {@link ItemStream} that delegates to a list of other streams. |
| 29 | * |
| 30 | * @author Dave Syer |
| 31 | * |
| 32 | */ |
| 33 | public class CompositeItemStream implements ItemStream { |
| 34 | |
| 35 | private List streams = new ArrayList(); |
| 36 | |
| 37 | /** |
| 38 | * Public setter for the listeners. |
| 39 | * |
| 40 | * @param listeners |
| 41 | */ |
| 42 | public void setStreams(ItemStream[] listeners) { |
| 43 | this.streams = Arrays.asList(listeners); |
| 44 | } |
| 45 | |
| 46 | /** |
| 47 | * |
| 48 | */ |
| 49 | public CompositeItemStream() { |
| 50 | super(); |
| 51 | } |
| 52 | |
| 53 | |
| 54 | /** |
| 55 | * Simple aggregate {@link ExecutionContext} provider for the contributions |
| 56 | * registered under the given key. |
| 57 | * |
| 58 | * @see org.springframework.batch.item.ItemStream#update(ExecutionContext) |
| 59 | */ |
| 60 | public void update(ExecutionContext executionContext) { |
| 61 | synchronized (streams) { |
| 62 | for (Iterator it = streams.iterator(); it.hasNext();) { |
| 63 | ItemStream itemStream = (ItemStream) it.next(); |
| 64 | itemStream.update(executionContext); |
| 65 | } |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | /** |
| 70 | * Register a {@link ItemStream} as one of the interesting providers under |
| 71 | * the provided key. |
| 72 | * |
| 73 | */ |
| 74 | public void register(ItemStream stream) { |
| 75 | synchronized (streams) { |
| 76 | if (!streams.contains(stream)) { |
| 77 | streams.add(stream); |
| 78 | } |
| 79 | } |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * Broadcast the call to close. |
| 84 | * @throws ItemStreamException |
| 85 | */ |
| 86 | public void close(ExecutionContext executionContext) throws ItemStreamException { |
| 87 | synchronized (streams) { |
| 88 | for (Iterator it = streams.iterator(); it.hasNext();) { |
| 89 | ItemStream itemStream = (ItemStream) it.next(); |
| 90 | itemStream.close(executionContext); |
| 91 | } |
| 92 | } |
| 93 | } |
| 94 | |
| 95 | /** |
| 96 | * Broadcast the call to open. |
| 97 | * @throws ItemStreamException |
| 98 | */ |
| 99 | public void open(ExecutionContext executionContext) throws ItemStreamException { |
| 100 | synchronized (streams) { |
| 101 | for (Iterator it = streams.iterator(); it.hasNext();) { |
| 102 | ItemStream itemStream = (ItemStream) it.next(); |
| 103 | itemStream.open(executionContext); |
| 104 | } |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | } |