uk.org.ogsadai.activity.delivery
Class AbstractDeliverToAddressActivity

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

Direct Known Subclasses:

DeliverToFileActivity, DeliverToURLActivity

public abstract class AbstractDeliverToAddressActivity

extends Activity

This abstract class contains methods to connect to a java.io.InputStream and push information onto that stream from OGSA-DAI.

The output of another activity can be connected to the input of this activity,

Author:

The OGSA-DAI Project Team

Field Summary

private static java.lang.String	COPYRIGHT_NOTICE Copyright statement
private static DAILogger	LOG Logger object for logging in this class
protected BlockReader	mInput Activity input - output from another activity
protected java.io.OutputStream	mOutputStream Stream managing the data delivery
protected java.lang.String	mToAddress String version of address to send data to.
protected java.io.Writer	mWriter Writer managing the data delivery (for strings)

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

mContext, mExternalInputs, mExternalOutputs, mInternalInputs, mInternalOutputs

Constructor Summary

AbstractDeliverToAddressActivity(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.
abstract void	processFirst() This method is called during the first iteration of processing an activity.
protected void	setupInput(org.w3c.dom.Element fromElement) Gets the name of the activity intput stream from a from attribute of the given element and saves this in the activity's list of internal inputs.

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

cleanUp, connectsTo, createOutputPipe, getActivityConfiguration, getActivityName, getCause, getName, getObservableStatus, getProperties, getSession, getStatus, hasActivityConfiguration, hasProperties, process, 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

Copyright statement

See Also:

Constant Field Values

LOG

private static final DAILogger LOG

Logger object for logging in this class

mInput

protected BlockReader mInput

Activity input - output from another activity

mOutputStream

protected java.io.OutputStream mOutputStream

Stream managing the data delivery

mWriter

protected java.io.Writer mWriter

Writer managing the data delivery (for strings)

mToAddress

protected java.lang.String mToAddress

String version of address to send data to.

Constructor Detail

AbstractDeliverToAddressActivity

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

Method Detail

setupInput

protected void setupInput(org.w3c.dom.Element fromElement)

Gets the name of the activity intput stream from a from attribute of the given element and saves this in the activity's list of internal inputs.

Parameters:

fromElement - Element from the request.

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.

processFirst

public abstract void processFirst()

Description copied from class: Activity

This method is called during the first iteration of processing an activity. It can be overridden by subclasses to define some processing that should be done only once during the first iteration of the activity processing, for example evaluating a database query.

Overrides:

processFirst in class Activity

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.

Specified by:

processBlock in class Activity