org.apache.commons.pipeline.stage
Class BaseStage

java.lang.Object
  org.apache.commons.pipeline.stage.BaseStage

All Implemented Interfaces:

Stage

Direct Known Subclasses:

AddToCollectionStage, DynamicLookupStaticMethodStage, FileFinderStage, FtpFileDownloadStage, HttpFileDownloadStage, InputStreamLineBreakStage, InvokeMethodStage, InvokeStaticMethodStage, KeyWaitBufferStage, LogStage, PipelineShutdownStage, RaiseEventStage, RaiseKeyAvailableEventStage, URLToInputStreamStage

public abstract class BaseStage
extends Object
implements Stage

This is a simple base class for Stages with no-op implementations of the preprocess(), #process(), postprocess(), and release() methods.

Field Summary

protected StageContext

context The context in which the stage runs.

Constructor Summary

BaseStage()

Method Summary

void	emit(Object obj) Convenience method to feed the specified object to the next stage downstream.
void	emit(String branch, Object obj) Convenience method to feed the specified object to the first stage of the specified branch.
void	init(StageContext context) This implementation of init() simply stores a reference to the stage context.
void	postprocess() No-op implementation.
void	preprocess() No-op implementation.
void	process(Object obj) The only operation performed by this implementation of process() is to feed the specified object to the downstream feeder.
void	release() No-op implementation.

Methods inherited from class java.lang.Object

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

Field Detail

context

protected StageContext context

The context in which the stage runs.

Constructor Detail

BaseStage

public BaseStage()

Method Detail

init

public void init(StageContext context)

This implementation of init() simply stores a reference to the stage context.

Specified by:

init in interface Stage

Parameters:

context - the StageContext within which the stage sill be run

preprocess

public void preprocess()
                throws StageException

No-op implementation. This method should be overridden to provide preprocessing capability for the stage.

Specified by:

preprocess in interface Stage

Throws:

StageException - an Exception thrown by an overriding implementation should be wrapped in a StageException

See Also:

Stage.preprocess()

process

public void process(Object obj)
             throws StageException

The only operation performed by this implementation of process() is to feed the specified object to the downstream feeder. This method should be overridden to provide processing capability for the stage.

Specified by:

process in interface Stage

Parameters:

obj - Object to be passed to downstream pipeline.

Throws:

StageException - an Exception thrown by an overriding implementation should be wrapped in a StageException

postprocess

public void postprocess()
                 throws StageException

No-op implementation. This method should be overridden to provide postprocessing capability for the stage.

Specified by:

postprocess in interface Stage

Throws:

StageException - an Exception thrown by an overriding implementation should be wrapped in a StageException

release

public void release()

No-op implementation. This method should be overridden to provide resource release capability for the stage. Implementations overriding this method should clean up any lingering resources that might otherwise be left allocated if an exception is thrown during processing.

Specified by:

release in interface Stage

See Also:

Stage.release()

emit

public final void emit(Object obj)

Convenience method to feed the specified object to the next stage downstream.

emit

public final void emit(String branch,
                       Object obj)

Convenience method to feed the specified object to the first stage of the specified branch.