Package org.springframework.batch.integration.async

Class AsyncItemProcessor<I,​O>

  • Type Parameters:
    I - the input object type
    O - the output object type (will be wrapped in a Future)
    All Implemented Interfaces:
    ItemProcessor<I,​java.util.concurrent.Future<O>>, org.springframework.beans.factory.InitializingBean
    public class AsyncItemProcessor<I,​O>
extends java.lang.Object
implements ItemProcessor<I,​java.util.concurrent.Future<O>>, org.springframework.beans.factory.InitializingBean
    An ItemProcessor that delegates to a nested processor and in the background. To allow for background processing the return value from the processor is a Future which needs to be unpacked before the item can be used by a client. Because the Future is typically unwrapped in the ItemWriter, there are lifecycle and stats limitations (since the framework doesn't know what the result of the processor is). While not an exhaustive list, things like StepExecution.filterCount will not reflect the number of filtered items and ItemProcessListener.onProcessError(Object, Exception) will not be called.
    Author:
    Dave Syer
    See Also:
    AsyncItemWriter

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and TypeMethodDescription
      voidafterPropertiesSet()
      Check mandatory properties (the setDelegate(ItemProcessor)).
      java.util.concurrent.Future<O>process​(I item)
      Transform the input by delegating to the provided item processor.
      voidsetDelegate​(ItemProcessor<I,​O> delegate)
      The ItemProcessor to use to delegate processing to in a background thread.
      voidsetTaskExecutor​(org.springframework.core.task.TaskExecutor taskExecutor)
      The TaskExecutor to use to allow the item processing to proceed in the background.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • AsyncItemProcessor

        public AsyncItemProcessor()

    • Method Detail

      • afterPropertiesSet

        public void afterPropertiesSet()
                        throws java.lang.Exception
        Check mandatory properties (the setDelegate(ItemProcessor)).
        Specified by:
        afterPropertiesSet in interface org.springframework.beans.factory.InitializingBean
        Throws:
        java.lang.Exception
        See Also:
        InitializingBean.afterPropertiesSet()

      • setDelegate

        public void setDelegate​(ItemProcessor<I,​O> delegate)
        The ItemProcessor to use to delegate processing to in a background thread.
        Parameters:
        delegate - the ItemProcessor to use as a delegate

      • setTaskExecutor

        public void setTaskExecutor​(org.springframework.core.task.TaskExecutor taskExecutor)
        The TaskExecutor to use to allow the item processing to proceed in the background. Defaults to a SyncTaskExecutor so no threads are created unless this is overridden.
        Parameters:
        taskExecutor - a TaskExecutor

      • process

        public java.util.concurrent.Future<O> process​(I item)
                                       throws java.lang.Exception
        Transform the input by delegating to the provided item processor. The return value is wrapped in a Future so that clients can unpack it later.
        Specified by:
        process in interface ItemProcessor<I,​O>
        Parameters:
        item - to be processed
        Returns:
        potentially modified or new item for continued processing, null if processing of the provided item should not continue.
        Throws:
        java.lang.Exception - thrown if exception occurs during processing.
        See Also:
        ItemProcessor.process(Object)