Class SimpleChunkProcessor<I,​O>

Constructor Detail

• SimpleChunkProcessor

  public SimpleChunkProcessor​(@Nullable
                              ItemProcessor<? super I,​? extends O> itemProcessor,
                              ItemWriter<? super O> itemWriter)

• SimpleChunkProcessor

  public SimpleChunkProcessor​(ItemWriter<? super O> itemWriter)

Method Detail

• setItemProcessor

  public void setItemProcessor​(ItemProcessor<? super I,​? extends O> itemProcessor)

  Parameters:

  itemProcessor - the ItemProcessor to set

• setItemWriter

  public void setItemWriter​(ItemWriter<? super O> itemWriter)

  Parameters:

  itemWriter - the ItemWriter to set

• afterPropertiesSet

  public void afterPropertiesSet()
                          throws java.lang.Exception

  Check mandatory properties.

  Specified by:

  afterPropertiesSet in interface org.springframework.beans.factory.InitializingBean

  Throws:

  java.lang.Exception

  See Also:

  InitializingBean.afterPropertiesSet()

• setListeners

  public void setListeners​(java.util.List<? extends StepListener> listeners)

  Register some StepListeners with the handler. Each will get the callbacks in the order specified at the correct stage.

  Parameters:

  listeners - list of StepListener instances.

• registerListener

  public void registerListener​(StepListener listener)

  Register a listener for callbacks at the appropriate stages in a process.

  Parameters:

  listener - a StepListener

• getListener

  protected MulticasterBatchListener<I,​O> getListener()

  Returns:

  the listener

• doProcess

  protected final O doProcess​(I item)
                       throws java.lang.Exception

  Parameters:

  item - the input item

  Returns:

  the result of the processing

  Throws:

  java.lang.Exception - thrown if error occurs.

• doWrite

  protected final void doWrite​(java.util.List<O> items)
                        throws java.lang.Exception

  Surrounds the actual write call with listener callbacks.

  Parameters:

  items - list of items to be written.

  Throws:

  java.lang.Exception - thrown if error occurs.

• doAfterWrite

  protected final void doAfterWrite​(java.util.List<O> items)

  Call the listener's after write method.

  Parameters:

  items - list of items that were just written.

• doOnWriteError

  protected final void doOnWriteError​(java.lang.Exception e,
                                      java.util.List<O> items)

  Call listener's writerError method.

  Parameters:

  e - exception that occurred.

  items - list of items that failed to be written.

• writeItems

  protected void writeItems​(java.util.List<O> items)
                     throws java.lang.Exception

  Parameters:

  items - list of items to be written.

  Throws:

  java.lang.Exception - thrown if error occurs.

• process

  public final void process​(StepContribution contribution,
                            Chunk<I> inputs)
                     throws java.lang.Exception

  Specified by:

  process in interface ChunkProcessor<I>

  Throws:

  java.lang.Exception

• initializeUserData

  protected void initializeUserData​(Chunk<I> inputs)

  Extension point for subclasses to allow them to memorise the contents of the inputs, in case they are needed for accounting purposes later. The default implementation sets up some user data to remember the original size of the inputs. If this method is overridden then some or all of isComplete(Chunk), getFilterCount(Chunk, Chunk) and getAdjustedOutputs(Chunk, Chunk) might also need to be, to ensure that the user data is handled consistently.

  Parameters:

  inputs - the inputs for the process

• getFilterCount

  protected int getFilterCount​(Chunk<I> inputs,
                               Chunk<O> outputs)

  Extension point for subclasses to calculate the filter count. Defaults to the difference between input size and output size.

  Parameters:

  inputs - the inputs after transformation

  outputs - the outputs after transformation

  Returns:

  the difference in sizes

  See Also:

  initializeUserData(Chunk)

• isComplete

  protected boolean isComplete​(Chunk<I> inputs)

  Extension point for subclasses that want to store additional data in the inputs. Default just checks if inputs are empty.

  Parameters:

  inputs - the input chunk

  Returns:

  true if it is empty

  See Also:

  initializeUserData(Chunk)

• getAdjustedOutputs

  protected Chunk<O> getAdjustedOutputs​(Chunk<I> inputs,
                                        Chunk<O> outputs)

  Extension point for subclasses that want to adjust the outputs based on additional saved data in the inputs. Default implementation just returns the outputs unchanged.

  Parameters:

  inputs - the inputs for the transformation

  outputs - the result of the transformation

  Returns:

  the outputs unchanged

  See Also:

  initializeUserData(Chunk)

• write

  protected void write​(StepContribution contribution,
                       Chunk<I> inputs,
                       Chunk<O> outputs)
                throws java.lang.Exception

  Simple implementation delegates to the doWrite(List) method and increments the write count in the contribution. Subclasses can handle more complicated scenarios, e.g.with fault tolerance. If output items are skipped they should be removed from the inputs as well.

  Parameters:

  contribution - the current step contribution

  inputs - the inputs that gave rise to the outputs

  outputs - the outputs to write

  Throws:

  java.lang.Exception - if there is a problem

• transform

  protected Chunk<O> transform​(StepContribution contribution,
                               Chunk<I> inputs)
                        throws java.lang.Exception

  Throws:

  java.lang.Exception