uk.org.ogsadai.activity.xmldb
Class XUpdateStatementActivity

java.lang.Object
  |
  +--uk.org.ogsadai.activity.Activity
        |
        +--uk.org.ogsadai.activity.xmldb.XMLDBActivity
              |
              +--uk.org.ogsadai.activity.xmldb.XUpdateStatementActivity

public class XUpdateStatementActivity

extends XMLDBActivity

An XMLDBActivity for performing XUpdate statements on XMLDB compliant database Collections and specified resources within them.

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

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
private java.lang.String	mExpression The XUpdate expression.
private java.lang.String	mResourceID The resource ID to update or null to update the whole collection.

Fields inherited from class uk.org.ogsadai.activity.xmldb.XMLDBActivity

mDataResource, mOutput, mSubCollectionName, mUserCredentials

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

mContext, mExternalInputs, mExternalOutputs, mInternalInputs, mInternalOutputs

Constructor Summary

XUpdateStatementActivity(org.w3c.dom.Element element)
Constructs an XUpdate activity using the specified XML element.

Method Summary

void	processBlock() Performs an iteration of the processing of an activity.
private java.lang.String	resultsToXML(long modifiedNodes) Converts the results of the XUpdate execution into an XML string representation.
private long	update() This method executes the XUpdate expression.

Methods inherited from class uk.org.ogsadai.activity.xmldb.XMLDBActivity

initialise

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

Copyright statement

See Also:

Constant Field Values

LOG

private static DAILogger LOG

Logger object for logging in this class

mExpression

private java.lang.String mExpression

The XUpdate expression.

mResourceID

private java.lang.String mResourceID

The resource ID to update or null to update the whole collection.

Constructor Detail

XUpdateStatementActivity

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

Constructs an XUpdate activity using the specified XML element.

Parameters:

element - Element to configure the activity with - from a perform document.

Throws:

ActivityCreationException - If there is a problem constructing the activity due to an implementation error or OGSA-DAI confguration problem.

ActivitySpecificationException - If there is a problem constructing the activity due to an invalid setting in element. mistake such as an invalid setting.

Method Detail

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 XMLDBActivity

update

private long update()
             throws ActivityExecutionException,
                    ActivitySpecificationException

This method executes the XUpdate expression.

Returns:

the number of nodes that were modified.

Throws:

ActivitySpecificationException - If some problem arises due to incorrect data from the client.

ActivityExecutionException - If some internal problem arises.

resultsToXML

private java.lang.String resultsToXML(long modifiedNodes)

Converts the results of the XUpdate execution into an XML string representation. The format is:

 <modifiedNodes>N<l/modifiedNodes>
 

Parameters:

modifiedNodes - number of modified nodes.

Returns:

string representation