org.springframework.batch.core.step.item.AlmostStatefulRetryChunkTests.java Source code

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Here is the source code for org.springframework.batch.core.step.item.AlmostStatefulRetryChunkTests.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
 *
 *      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.step.item;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;

/**
 * @author Dave Syer
 * 
 */
@RunWith(Parameterized.class)
public class AlmostStatefulRetryChunkTests {

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

    private final Chunk<String> chunk;

    private final int retryLimit;

    private int retryAttempts = 0;

    private static final int BACKSTOP_LIMIT = 1000;

    private int count = 0;

    public AlmostStatefulRetryChunkTests(String[] args, int limit) {
        chunk = new Chunk<String>();
        for (String string : args) {
            chunk.add(string);
        }
        this.retryLimit = limit;
    }

    @Test
    public void testRetry() throws Exception {
        logger.debug("Starting simple scenario");
        List<String> items = new ArrayList<String>(chunk.getItems());
        int before = items.size();
        items.removeAll(Collections.singleton("fail"));
        boolean error = true;
        while (error && count++ < BACKSTOP_LIMIT) {
            try {
                statefulRetry(chunk);
                error = false;
            } catch (Exception e) {
                error = true;
            }
        }
        logger.debug("Chunk: " + chunk);
        assertTrue("Backstop reached.  Probably an infinite loop...", count < BACKSTOP_LIMIT);
        assertFalse(chunk.getItems().contains("fail"));
        assertEquals(items, chunk.getItems());
        assertEquals(before - chunk.getItems().size(), chunk.getSkips().size());
    }

    /**
     * @param chunk
     * @throws Exception
     */
    private void statefulRetry(Chunk<String> chunk) throws Exception {
        if (retryAttempts <= retryLimit) {
            try {
                // N.B. a classic stateful retry goes straight to recovery here
                logger.debug(String.format("Retry (attempts=%d) chunk: %s", retryAttempts, chunk));
                doWrite(chunk.getItems());
                retryAttempts = 0;
            } catch (Exception e) {
                retryAttempts++;
                // stateful retry always rethrow
                throw e;
            }
        } else {
            try {
                logger.debug(String.format("Recover (attempts=%d) chunk: %s", retryAttempts, chunk));
                recover(chunk);
            } finally {
                retryAttempts = 0;
            }
        }
        // recovery
        return;

    }

    /**
     * @param chunk
     * @throws Exception
     */
    private void recover(Chunk<String> chunk) throws Exception {
        for (Chunk<String>.ChunkIterator iterator = chunk.iterator(); iterator.hasNext();) {
            String string = iterator.next();
            try {
                doWrite(Collections.singletonList(string));
            } catch (Exception e) {
                iterator.remove(e);
                throw e;
            }
        }
    }

    /**
     * @param items
     * @throws Exception
     */
    private void doWrite(List<String> items) throws Exception {
        if (items.contains("fail")) {
            throw new Exception();
        }
    }

    @Parameters
    public static List<Object[]> data() {
        List<Object[]> params = new ArrayList<Object[]>();
        params.add(new Object[] { new String[] { "foo" }, 0 });
        params.add(new Object[] { new String[] { "foo", "bar" }, 0 });
        params.add(new Object[] { new String[] { "foo", "bar", "spam" }, 0 });
        params.add(new Object[] { new String[] { "foo", "bar", "spam", "maps", "rab", "oof" }, 0 });
        params.add(new Object[] { new String[] { "fail" }, 0 });
        params.add(new Object[] { new String[] { "foo", "fail" }, 0 });
        params.add(new Object[] { new String[] { "fail", "bar" }, 0 });
        params.add(new Object[] { new String[] { "foo", "fail", "spam" }, 0 });
        params.add(new Object[] { new String[] { "fail", "bar", "spam" }, 0 });
        params.add(new Object[] { new String[] { "foo", "fail", "spam", "maps", "rab", "oof" }, 0 });
        params.add(new Object[] { new String[] { "foo", "fail", "spam", "fail", "rab", "oof" }, 0 });
        params.add(new Object[] { new String[] { "fail", "bar", "spam", "fail", "rab", "oof" }, 0 });
        params.add(new Object[] { new String[] { "foo", "fail", "fail", "fail", "rab", "oof" }, 0 });
        params.add(new Object[] { new String[] { "fail" }, 1 });
        params.add(new Object[] { new String[] { "foo", "fail", "fail", "fail", "rab", "oof" }, 1 });
        params.add(new Object[] { new String[] { "foo", "fail", "fail", "fail", "rab", "oof" }, 4 });
        return params;
    }
}