How to use

remove

method

in

org.springframework.batch.core.step.item.Chunk$ChunkIterator

iterator.remove();

private void checkSkipPolicy(Chunk<I>.ChunkIterator inputIterator, Chunk<O>.ChunkIterator outputIterator,
    Throwable e, StepContribution contribution, boolean recovery) throws Exception {
  logger.debug("Checking skip policy after failed write");
  if (shouldSkip(itemWriteSkipPolicy, e, contribution.getStepSkipCount())) {
    contribution.incrementWriteSkipCount();
    inputIterator.remove();
    outputIterator.remove(e);
    logger.debug("Skipping after failed write", e);
  }
  else {
    if (recovery) {
      // Only if already recovering should we check skip policy
      throw new RetryException("Non-skippable exception in recoverer", e);
    }
    else {
      if (e instanceof Exception) {
        throw (Exception) e;
      }
      else if (e instanceof Error) {
        throw (Error) e;
      }
      else {
        throw new RetryException("Non-skippable throwable in recoverer", e);
      }
    }
  }
}

@Override
public O recover(RetryContext context) throws Exception {
  Throwable e = context.getLastThrowable();
  if (shouldSkip(itemProcessSkipPolicy, e, contribution.getStepSkipCount())) {
    iterator.remove(e);
    contribution.incrementProcessSkipCount();
    logger.debug("Skipping after failed process", e);
    return null;
  }
  else {
    if (rollbackClassifier.classify(e)) {
      // Default is to rollback unless the classifier
      // allows us to continue
      throw new RetryException("Non-skippable exception in recoverer while processing", e);
    }
    iterator.remove(e);
    return null;
  }
}

iterator.remove();

inputIterator.remove();
outputIterator.remove();
  inputIterator.remove();
  outputIterator.remove();

private void checkSkipPolicy(Chunk<I>.ChunkIterator inputIterator, Chunk<O>.ChunkIterator outputIterator,
    Throwable e, StepContribution contribution, boolean recovery) throws Exception {
  logger.debug("Checking skip policy after failed write");
  if (shouldSkip(itemWriteSkipPolicy, e, contribution.getStepSkipCount())) {
    contribution.incrementWriteSkipCount();
    inputIterator.remove();
    outputIterator.remove(e);
    logger.debug("Skipping after failed write", e);
  }
  else {
    if (recovery) {
      // Only if already recovering should we check skip policy
      throw new RetryException("Non-skippable exception in recoverer", e);
    }
    else {
      if (e instanceof Exception) {
        throw (Exception) e;
      }
      else if (e instanceof Error) {
        throw (Error) e;
      }
      else {
        throw new RetryException("Non-skippable throwable in recoverer", e);
      }
    }
  }
}

private void checkSkipPolicy(Chunk<I>.ChunkIterator inputIterator, Chunk<O>.ChunkIterator outputIterator,
    Throwable e, StepContribution contribution, boolean recovery) throws Exception {
  logger.debug("Checking skip policy after failed write");
  if (shouldSkip(itemWriteSkipPolicy, e, contribution.getStepSkipCount())) {
    contribution.incrementWriteSkipCount();
    inputIterator.remove();
    outputIterator.remove(e);
    logger.debug("Skipping after failed write", e);
  }
  else {
    if (recovery) {
      // Only if already recovering should we check skip policy
      throw new RetryException("Non-skippable exception in recoverer", e);
    }
    else {
      if (e instanceof Exception) {
        throw (Exception) e;
      }
      else if (e instanceof Error) {
        throw (Error) e;
      }
      else {
        throw new RetryException("Non-skippable throwable in recoverer", e);
      }
    }
  }
}

protected Chunk<O> transform(StepContribution contribution, Chunk<I> inputs) throws Exception {
  Chunk<O> outputs = new Chunk<O>();
  for (Chunk<I>.ChunkIterator iterator = inputs.iterator(); iterator.hasNext();) {
    final I item = iterator.next();
    O output;
    try {
      output = doProcess(item);
    }
    catch (Exception e) {
      /*
       * For a simple chunk processor (no fault tolerance) we are done
       * here, so prevent any more processing of these inputs.
       */
      inputs.clear();
      throw e;
    }
    if (output != null) {
      outputs.add(output);
    }
    else {
      iterator.remove();
    }
  }
  return outputs;
}

private void checkSkipPolicy(Chunk<I>.ChunkIterator inputIterator, Chunk<O>.ChunkIterator outputIterator,
    Throwable e, StepContribution contribution, boolean recovery) throws Exception {
  logger.debug("Checking skip policy after failed write");
  if (shouldSkip(itemWriteSkipPolicy, e, contribution.getStepSkipCount())) {
    contribution.incrementWriteSkipCount();
    inputIterator.remove();
    outputIterator.remove(e);
    logger.debug("Skipping after failed write", e);
  }
  else {
    if (recovery) {
      // Only if already recovering should we check skip policy
      throw new RetryException("Non-skippable exception in recoverer", e);
    }
    else {
      if (e instanceof Exception) {
        throw (Exception) e;
      }
      else if (e instanceof Error) {
        throw (Error) e;
      }
      else {
        throw new RetryException("Non-skippable throwable in recoverer", e);
      }
    }
  }
}

protected Chunk<O> transform(StepContribution contribution, Chunk<I> inputs) throws Exception {
  Chunk<O> outputs = new Chunk<O>();
  for (Chunk<I>.ChunkIterator iterator = inputs.iterator(); iterator.hasNext();) {
    final I item = iterator.next();
    O output;
    try {
      output = doProcess(item);
    }
    catch (Exception e) {
      /*
       * For a simple chunk processor (no fault tolerance) we are done
       * here, so prevent any more processing of these inputs.
       */
      inputs.clear();
      throw e;
    }
    if (output != null) {
      outputs.add(output);
    }
    else {
      iterator.remove();
    }
  }
  return outputs;
}

@Override
public O recover(RetryContext context) throws Exception {
  Throwable e = context.getLastThrowable();
  if (shouldSkip(itemProcessSkipPolicy, e, contribution.getStepSkipCount())) {
    iterator.remove(e);
    contribution.incrementProcessSkipCount();
    logger.debug("Skipping after failed process", e);
    return null;
  }
  else {
    if (rollbackClassifier.classify(e)) {
      // Default is to rollback unless the classifier
      // allows us to continue
      throw new RetryException("Non-skippable exception in recoverer while processing", e);
    }
    iterator.remove(e);
    return null;
  }
}

@Override
public O recover(RetryContext context) throws Exception {
  Throwable e = context.getLastThrowable();
  if (shouldSkip(itemProcessSkipPolicy, e, contribution.getStepSkipCount())) {
    iterator.remove(e);
    contribution.incrementProcessSkipCount();
    logger.debug("Skipping after failed process", e);
    return null;
  }
  else {
    if (rollbackClassifier.classify(e)) {
      // Default is to rollback unless the classifier
      // allows us to continue
      throw new RetryException("Non-skippable exception in recoverer while processing", e);
    }
    iterator.remove(e);
    return null;
  }
}

protected Chunk<O> transform(StepContribution contribution, Chunk<I> inputs) throws Exception {
  Chunk<O> outputs = new Chunk<O>();
  for (Chunk<I>.ChunkIterator iterator = inputs.iterator(); iterator.hasNext();) {
    final I item = iterator.next();
    O output;
    try {
      output = doProcess(item);
    }
    catch (Exception e) {
      /*
       * For a simple chunk processor (no fault tolerance) we are done
       * here, so prevent any more processing of these inputs.
       */
      inputs.clear();
      throw e;
    }
    if (output != null) {
      outputs.add(output);
    }
    else {
      iterator.remove();
    }
  }
  return outputs;
}

@Override
public O recover(RetryContext context) throws Exception {
  Throwable e = context.getLastThrowable();
  if (shouldSkip(itemProcessSkipPolicy, e, contribution.getStepSkipCount())) {
    iterator.remove(e);
    contribution.incrementProcessSkipCount();
    logger.debug("Skipping after failed process", e);
    return null;
  }
  else {
    if (rollbackClassifier.classify(e)) {
      // Default is to rollback unless the classifier
      // allows us to continue
      throw new RetryException("Non-skippable exception in recoverer while processing", e);
    }
    iterator.remove(e);
    return null;
  }
}

protected Chunk<O> transform(StepContribution contribution, Chunk<I> inputs) throws Exception {
  Chunk<O> outputs = new Chunk<O>();
  for (Chunk<I>.ChunkIterator iterator = inputs.iterator(); iterator.hasNext();) {
    final I item = iterator.next();
    O output = doProcess(item);
    if (output != null) {
      outputs.add(output);
    }
    else {
      iterator.remove();
    }
  }
  return outputs;
}

private void checkSkipPolicy(Chunk<I>.ChunkIterator inputIterator, Chunk<O>.ChunkIterator outputIterator,
    Throwable e, StepContribution contribution) {
  logger.debug("Checking skip policy after failed write");
  if (shouldSkip(itemWriteSkipPolicy, e, contribution.getStepSkipCount())) {
    contribution.incrementWriteSkipCount();
    inputIterator.remove();
    outputIterator.remove(e);
    logger.debug("Skipping after failed write", e);
  }
  else {
    throw new RetryException("Non-skippable exception in recoverer", e);
  }
}

public O recover(RetryContext context) throws Exception {
  Throwable e = context.getLastThrowable();
  if (shouldSkip(itemProcessSkipPolicy, e, contribution.getStepSkipCount())) {
    contribution.incrementProcessSkipCount();
    iterator.remove(e);
    logger.debug("Skipping after failed process", e);
    return null;
  }
  else {
    throw new RetryException("Non-skippable exception in recoverer while processing", e);
  }
}

  outputIterator.remove();
  return;
inputIterator.remove();
outputIterator.remove();
    inputIterator.remove();
    outputIterator.remove();

protected Chunk<O> transform(StepContribution contribution, Chunk<I> inputs) throws Exception {
  Chunk<O> outputs = new Chunk<>();
  for (Chunk<I>.ChunkIterator iterator = inputs.iterator(); iterator.hasNext();) {
    final I item = iterator.next();
    O output;
    try {
      output = doProcess(item);
    }
    catch (Exception e) {
      /*
       * For a simple chunk processor (no fault tolerance) we are done
       * here, so prevent any more processing of these inputs.
       */
      inputs.clear();
      throw e;
    }
    if (output != null) {
      outputs.add(output);
    }
    else {
      iterator.remove();
    }
  }
  return outputs;
}

/**
 * @param chunk Chunk to recover
 */
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;
    }
  }
}