DeliverToNullActivity (OGSA-DAI -- (c) International Business Machines Corporation, 2002-2006, The University of Edinburgh, 2002-2006)

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uk.org.ogsadai.activity.delivery
Class DeliverToNullActivity

java.lang.Object
  |
  +--uk.org.ogsadai.activity.Activity
        |
        +--uk.org.ogsadai.activity.delivery.DeliverToNullActivity

public class DeliverToNullActivity
extends Activity

This activity simply throws away its input. The activity can be added to the end of an activity pipeline to turn a sychronous request into an asynchronous one. It should only be used if the output at the end of the pipeline is of no interest to the client as there will be no way to retrieve it.

For information on this activity see the OGSA-DAI user doc: OGSA-DAI/doc/interaction/activities/delivery/deliverToNull.html

Author:: OGSA-DAI team

Field Summary
`private static java.lang.String`	`COPYRIGHT_NOTICE` Copyright statement
`private BlockReader`	`mInput` Activity input - output from another activity

Fields inherited from class uk.org.ogsadai.activity.Activity

mContext, mExternalInputs, mExternalOutputs, mInternalInputs, mInternalOutputs

Constructor Summary
`DeliverToNullActivity(org.w3c.dom.Element element)`

Method Summary
`void`	`initialise()` This method should be overridden by subclasses to perform any initialisation they require before the `process` method invocations begin.
`void`	`processBlock()` Performs an iteration of the processing of an activity.

Methods inherited from class uk.org.ogsadai.activity.Activity

cleanUp, connectsTo, createOutputPipe, getActivityConfiguration, getActivityName, getCause, getName, getObservableStatus, getProperties, getSession, getStatus, hasActivityConfiguration, hasProperties, process, processFirst, setActivityName, setCompleted, setError

Methods inherited from class java.lang.Object

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

Field Detail

COPYRIGHT_NOTICE

private static final java.lang.String COPYRIGHT_NOTICE

See Also:: Constant Field Values

mInput

private BlockReader mInput

Activity input - output from another activity

Constructor Detail

DeliverToNullActivity

public DeliverToNullActivity(org.w3c.dom.Element element)
                      throws ActivityCreationException,
                             ActivitySpecificationException

Method Detail

initialise

public void initialise()
                throws ActivitySpecificationException,
                       ActivityExecutionException

Description copied from class: Activity

This method should be overridden by subclasses to perform any initialisation they require before the process method invocations begin. This might be used for setting up convenient fields to reference objects contained in the context. It shouldn't be used for opening resources. That should be done in processFirst.

Overrides:: initialise in class Activity

Throws:: ActivityExecutionException - If some system problem prevents the activity from initialising.; ActivitySpecificationException - If a problem with settings provided by a client prevents the activity from initialising.

processBlock

public void processBlock()

Description copied from class: Activity

Performs an iteration of the processing of an activity. This may involve reading a block of input data and writing a block of output data, or may involve some other kind of processing. When an activity is processed by the OGSA-DAI engine, this method will be invoked repeatedly until the activity either completes or stops due to an error or termination call. An implementation of this method should invoke the setCompleted method to indicate that processing is complete, or the setError method if an error occurs that will prevent the processing from completing.