org.works.batch.item.SynchronizedItemReader.java Source code

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Here is the source code for org.works.batch.item.SynchronizedItemReader.java

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/*
 * Copyright 2007-2011 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.works.batch.item;

import org.springframework.batch.item.ExecutionContext;
import org.springframework.batch.item.ItemReader;
import org.springframework.batch.item.ItemStream;
import org.springframework.batch.item.ItemStreamException;
import org.springframework.batch.item.ItemStreamReader;
import org.springframework.batch.item.NonTransientResourceException;
import org.springframework.batch.item.ParseException;
import org.springframework.batch.item.UnexpectedInputException;

/**
 * {@link ItemStreamReader} with a synchronized read method. Is useful when
 * needing to synchronize on read in a concurrent environment.
 * 
 * @author Marten Deinum
 */
public class SynchronizedItemReader<T> implements ItemStreamReader<T> {

    private final ItemReader<T> delegate;

    /**
     * 
     * @param delegate
     *            delegate ItemReader which does the actual work.
     */
    public SynchronizedItemReader(final ItemReader<T> delegate) {
        super();
        this.delegate = delegate;
    }

    public synchronized T read()
            throws Exception, UnexpectedInputException, ParseException, NonTransientResourceException {
        return this.delegate.read();
    }

    public void open(final ExecutionContext executionContext) throws ItemStreamException {
        if (this.delegate instanceof ItemStream) {
            ((ItemStream) this.delegate).open(executionContext);
        }
    }

    public void update(final ExecutionContext executionContext) throws ItemStreamException {
        if (this.delegate instanceof ItemStream) {
            ((ItemStream) this.delegate).update(executionContext);
        }
    }

    public void close() throws ItemStreamException {
        if (this.delegate instanceof ItemStream) {
            ((ItemStream) this.delegate).close();
        }

    }
}