/*
    * Copyright 2006-2007 the original author or authors.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.springframework.batch.item.support;
  
  import java.util.List;
  
  import org.springframework.batch.item.ExecutionContext;
  import org.springframework.batch.item.ItemStream;
  import org.springframework.batch.item.ItemStreamException;
  import org.springframework.batch.item.ItemStreamWriter;
  import org.springframework.batch.item.ItemWriter;
  import org.springframework.beans.factory.InitializingBean;
  import org.springframework.util.Assert;
  
  /**
   * Calls a collection of {@link ItemWriter}s in fixed-order sequence.<br/>
   * <br/>
   * 
   * The implementation is thread-safe if all delegates are thread-safe.
   * 
   * @author Robert Kasanicky
   * @author Dave Syer
   */
  public class CompositeItemWriter<T> implements ItemStreamWriter<T>, InitializingBean {
  
  	private List<ItemWriter<? super T>> delegates;
  
  	private boolean ignoreItemStream = false;
  
  	public void setIgnoreItemStream(boolean ignoreItemStream) {
  		this.ignoreItemStream = ignoreItemStream;
  	}
  
      @Override
  	public void write(List<? extends T> item) throws Exception {
  		for (ItemWriter<? super T> writer : delegates) {
  			writer.write(item);
  		}
  	}
  
      @Override
  	public void afterPropertiesSet() throws Exception {
  		Assert.notNull(delegates, "The 'delgates' may not be null");
  		Assert.notEmpty(delegates, "The 'delgates' may not be empty");
  	}
  
  	public void setDelegates(List<ItemWriter<? super T>> delegates) {
  		this.delegates = delegates;
  	}
  
      @Override
  	public void close() throws ItemStreamException {
  		for (ItemWriter<? super T> writer : delegates) {
  			if (!ignoreItemStream && (writer instanceof ItemStream)) {
  				((ItemStream) writer).close();
  			}
  		}
  	}
  
      @Override
  	public void open(ExecutionContext executionContext) throws ItemStreamException {
  		for (ItemWriter<? super T> writer : delegates) {
  			if (!ignoreItemStream && (writer instanceof ItemStream)) {
  				((ItemStream) writer).open(executionContext);
  			}
  		}
  	}
  
      @Override
  	public void update(ExecutionContext executionContext) throws ItemStreamException {
  		for (ItemWriter<? super T> writer : delegates) {
  			if (!ignoreItemStream && (writer instanceof ItemStream)) {
  				((ItemStream) writer).update(executionContext);
  			}
  		}
  	}
  
  }