org.springframework.batch.core.partition.ExampleItemReader.java Source code

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Here is the source code for org.springframework.batch.core.partition.ExampleItemReader.java

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/*
 * Copyright 2008-2013 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.core.partition;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.batch.item.ExecutionContext;
import org.springframework.batch.item.ItemStreamException;
import org.springframework.batch.item.ItemStreamReader;
import org.springframework.batch.item.support.AbstractItemStreamItemReader;
import org.springframework.util.ClassUtils;

/**
 * {@link ItemStreamReader} with hard-coded input data.
 */
public class ExampleItemReader extends AbstractItemStreamItemReader<String> {

    private Log logger = LogFactory.getLog(getClass());

    private String[] input = { "Hello", "world!", "Go", "on", "punk", "make", "my", "day!" };

    private int index = 0;

    private int min = 0;

    private int max = Integer.MAX_VALUE;

    public static volatile boolean fail = false;

    public ExampleItemReader() {
        this.setExecutionContextName(ClassUtils.getShortName(this.getClass()));
    }

    /**
     * @param min the min to set
     */
    public void setMin(int min) {
        this.min = min;
    }

    /**
     * @param max the max to set
     */
    public void setMax(int max) {
        this.max = max;
    }

    /**
     * Reads next record from input
     */
    @Override
    public String read() throws Exception {
        if (index >= input.length || index >= max) {
            return null;
        }
        logger.info(String.format("Processing input index=%s, item=%s, in (%s)", index, input[index], this));
        if (fail && index == 4) {
            synchronized (ExampleItemReader.class) {
                if (fail) {
                    // Only fail once per flag setting...
                    fail = false;
                    logger.info(String.format("Throwing exception index=%s, item=%s, in (%s)", index, input[index],
                            this));
                    index++;
                    throw new RuntimeException("Planned failure");
                }
            }
        }
        return input[index++];
    }

    @Override
    public void open(ExecutionContext executionContext) throws ItemStreamException {
        super.open(executionContext);
        index = (int) executionContext.getLong(getExecutionContextKey("POSITION"), min);
    }

    @Override
    public void update(ExecutionContext executionContext) throws ItemStreamException {
        super.update(executionContext);
        executionContext.putLong(getExecutionContextKey("POSITION"), index);
    }

}