org.springframework.batch.item.support.CompositeItemWriter.java Source code

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Here is the source code for org.springframework.batch.item.support.CompositeItemWriter.java

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/*
 * 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
 *
 *      https://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 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;

import java.util.List;

/**
 * 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;

    /**
     * Establishes the policy whether to call the open, close, or update methods for the
     * item writer delegates associated with the CompositeItemWriter.
     * 
     * @param ignoreItemStream if false the delegates' open, close, or update methods will
     * be called when the corresponding methods on the CompositeItemWriter are called. If
     * true the delegates' open, close, nor update methods will not be called (default is 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 'delegates' may not be null");
        Assert.notEmpty(delegates, "The 'delegates' may not be empty");
    }

    /**
     * The list of item writers to use as delegates. Items are written to each of the
     * delegates.
     *
     * @param delegates the list of delegates to use.  The delegates list must not be null nor 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);
            }
        }
    }

}