001/* 002 * Copyright 2006-2007 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.batch.item.support; 018 019import org.springframework.batch.item.ExecutionContext; 020import org.springframework.batch.item.ItemStream; 021import org.springframework.batch.item.ItemStreamException; 022import org.springframework.batch.item.ItemStreamWriter; 023import org.springframework.batch.item.ItemWriter; 024import org.springframework.beans.factory.InitializingBean; 025import org.springframework.util.Assert; 026 027import java.util.List; 028 029/** 030 * Calls a collection of {@link ItemWriter}s in fixed-order sequence.<br> 031 * <br> 032 * 033 * The implementation is thread-safe if all delegates are thread-safe. 034 * 035 * @author Robert Kasanicky 036 * @author Dave Syer 037 */ 038public class CompositeItemWriter<T> implements ItemStreamWriter<T>, InitializingBean { 039 040 private List<ItemWriter<? super T>> delegates; 041 042 private boolean ignoreItemStream = false; 043 044 /** 045 * Establishes the policy whether to call the open, close, or update methods for the 046 * item writer delegates associated with the CompositeItemWriter. 047 * 048 * @param ignoreItemStream if false the delegates' open, close, or update methods will 049 * be called when the corresponding methods on the CompositeItemWriter are called. If 050 * true the delegates' open, close, nor update methods will not be called (default is false). 051 */ 052 public void setIgnoreItemStream(boolean ignoreItemStream) { 053 this.ignoreItemStream = ignoreItemStream; 054 } 055 056 @Override 057 public void write(List<? extends T> item) throws Exception { 058 for (ItemWriter<? super T> writer : delegates) { 059 writer.write(item); 060 } 061 } 062 063 @Override 064 public void afterPropertiesSet() throws Exception { 065 Assert.notNull(delegates, "The 'delegates' may not be null"); 066 Assert.notEmpty(delegates, "The 'delegates' may not be empty"); 067 } 068 069 /** 070 * The list of item writers to use as delegates. Items are written to each of the 071 * delegates. 072 * 073 * @param delegates the list of delegates to use. The delegates list must not be null nor be empty. 074 */ 075 public void setDelegates(List<ItemWriter<? super T>> delegates) { 076 this.delegates = delegates; 077 } 078 079 @Override 080 public void close() throws ItemStreamException { 081 for (ItemWriter<? super T> writer : delegates) { 082 if (!ignoreItemStream && (writer instanceof ItemStream)) { 083 ((ItemStream) writer).close(); 084 } 085 } 086 } 087 088 @Override 089 public void open(ExecutionContext executionContext) throws ItemStreamException { 090 for (ItemWriter<? super T> writer : delegates) { 091 if (!ignoreItemStream && (writer instanceof ItemStream)) { 092 ((ItemStream) writer).open(executionContext); 093 } 094 } 095 } 096 097 @Override 098 public void update(ExecutionContext executionContext) throws ItemStreamException { 099 for (ItemWriter<? super T> writer : delegates) { 100 if (!ignoreItemStream && (writer instanceof ItemStream)) { 101 ((ItemStream) writer).update(executionContext); 102 } 103 } 104 } 105 106}