Example usage for org.springframework.batch.repeat RepeatCallback RepeatCallback

Introduction

In this page you can find the example usage for org.springframework.batch.repeat RepeatCallback RepeatCallback.

Prototype

RepeatCallback

Source Link

Usage

From source file:org.springframework.batch.core.jsr.step.item.JsrChunkProcessor.java

/**
 * Loops through reading (via {@link #provide(StepContribution, Chunk)} and
 * processing (via {@link #transform(StepContribution, Object)}) until the chunk
 * is complete.  Once the chunk is complete, the results are written (via
 * {@link #persist(StepContribution, Chunk)}.
 *
 * @see ChunkProcessor#process(StepContribution, Chunk)
 * @param contribution a {@link StepContribution}
 * @param chunk a {@link Chunk}//w ww  .  jav a  2 s.  co m
 */
@Override
public void process(final StepContribution contribution, final Chunk<I> chunk) throws Exception {

    final AtomicInteger filterCount = new AtomicInteger(0);
    final Chunk<O> output = new Chunk<O>();

    repeatTemplate.iterate(new RepeatCallback() {

        @Override
        public RepeatStatus doInIteration(RepeatContext context) throws Exception {
            I item = provide(contribution, chunk);

            if (item != null) {
                contribution.incrementReadCount();
            } else {
                return RepeatStatus.FINISHED;
            }

            O processedItem = transform(contribution, item);

            if (processedItem == null) {
                filterCount.incrementAndGet();
            } else {
                output.add(processedItem);
            }

            return RepeatStatus.CONTINUABLE;
        }
    });

    contribution.incrementFilterCount(filterCount.get());
    if (output.size() > 0) {
        persist(contribution, output);
    }
}

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From source file:org.springframework.batch.core.step.item.SimpleChunkProvider.java

@Override
public Chunk<I> provide(final StepContribution contribution) throws Exception {

    final Chunk<I> inputs = new Chunk<I>();
    repeatOperations.iterate(new RepeatCallback() {

        @Override//from   w  w  w.j  av a 2s . c  o m
        public RepeatStatus doInIteration(final RepeatContext context) throws Exception {
            I item = null;
            try {
                item = read(contribution, inputs);
            } catch (SkipOverflowException e) {
                // read() tells us about an excess of skips by throwing an
                // exception
                return RepeatStatus.FINISHED;
            }
            if (item == null) {
                inputs.setEnd();
                return RepeatStatus.FINISHED;
            }
            inputs.add(item);
            contribution.incrementReadCount();
            return RepeatStatus.CONTINUABLE;
        }

    });

    return inputs;

}

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From source file:org.springframework.batch.repeat.support.TaskExecutorRepeatTemplateBulkAsynchronousTests.java

@Before
public void setUp() {

    template = new TaskExecutorRepeatTemplate();
    TaskExecutor taskExecutor = new SimpleAsyncTaskExecutor();
    threadPool.setMaxPoolSize(300);//  ww w.j a  va 2  s.  c  o m
    threadPool.setCorePoolSize(10);
    threadPool.setQueueCapacity(0);
    threadPool.afterPropertiesSet();
    taskExecutor = threadPool;
    template.setTaskExecutor(taskExecutor);
    template.setThrottleLimit(throttleLimit);

    items = Collections.synchronizedList(new ArrayList<String>());

    callback = new RepeatCallback() {

        private volatile AtomicInteger count = new AtomicInteger(0);

        @Override
        public RepeatStatus doInIteration(RepeatContext context) throws Exception {
            int position = count.incrementAndGet();
            String item = position <= total ? "" + position : null;
            items.add("" + item);
            if (item != null) {
                beBusy();
            }
            /*
             * In a multi-threaded task, one of the callbacks can call
             * FINISHED early, while other threads are still working, and
             * would do more work if the callback was called again. (This
             * happens for instance if there is a failure and you want to
             * retry the work.)
             */
            RepeatStatus result = RepeatStatus.continueIf(position != early && item != null);
            if (position == error) {
                throw new RuntimeException("Planned");
            }
            if (!result.isContinuable()) {
                logger.debug("Returning " + result + " for count=" + position);
            }
            return result;
        }
    };

}

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From source file:org.springframework.batch.repeat.support.TaskExecutorRepeatTemplateBulkAsynchronousTests.java

@Test
public void testErrorThrownByCallback() throws Exception {

    callback = new RepeatCallback() {

        private volatile AtomicInteger count = new AtomicInteger(0);

        @Override//from ww  w  .  j ava 2 s .c  om
        public RepeatStatus doInIteration(RepeatContext context) throws Exception {
            int position = count.incrementAndGet();

            if (position == 4) {
                throw new OutOfMemoryError("Planned");
            } else {
                return RepeatStatus.CONTINUABLE;
            }
        }
    };

    template.setCompletionPolicy(new SimpleCompletionPolicy(10));

    try {
        template.iterate(callback);
        fail("Expected planned exception");
    } catch (OutOfMemoryError oome) {
        assertEquals("Planned", oome.getMessage());
    } catch (Exception e) {
        e.printStackTrace();
        fail("Wrong exception was thrown: " + e);
    }
}

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