uk.org.ogsadai.activity.xmldb
Class XMLBulkLoadActivity

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

public class XMLBulkLoadActivity

extends XMLDBActivity

An XMLDBActivity for bulk loading data into a XMLDB compliant database collection.

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

Author:

The OGSA-DAI Project Team

Field Summary

static java.lang.String	ATTRIBUTE_CREATE Constant for parsing activity XML - create new resource
private static java.lang.String	COPYRIGHT_NOTICE Copyright statement
static java.lang.String	ELEMENT_FROM_LOCAL Constant for parsing activity XML - activity input
static java.lang.String	ELEMENT_OUTPUT Constant for parsing activity XML - activity output
static java.lang.String	FOOTER Footer for the XML representation of a set of resources.
static java.lang.String	HEADER Header for the XML representation of a set of resources.
private static DAILogger	LOG Logger object for logging in this class
private org.xmldb.api.base.Collection	mCollection Collection into which the resources will be loaded
private boolean	mCreateCollectionIfNotExists should we create a new collection if it doesn't exist?
private int	mCurrentResource Number of the resource we are currently processing
private BlockReader	mInput Input stream from another activity, providing the resources
private org.w3c.dom.NodeList	mResources Resources for bulk loading if they are included in the request

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

XMLBulkLoadActivity(org.w3c.dom.Element element)
Constructs an XMLBulkLoad activity using the specified XML element.

Method Summary

private void	addDocument(org.w3c.dom.Element element) Add a resource to the current collection.
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.
void	processFirst() This method is called during the first iteration of processing an activity.
private java.lang.String	resultsToXML(int numResources) Converts the results of the bulk load execution into an XML string representation.

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 DAILogger LOG

Logger object for logging in this class

ELEMENT_FROM_LOCAL

public static final java.lang.String ELEMENT_FROM_LOCAL

Constant for parsing activity XML - activity input

See Also:

Constant Field Values

ELEMENT_OUTPUT

public static final java.lang.String ELEMENT_OUTPUT

Constant for parsing activity XML - activity output

See Also:

Constant Field Values

ATTRIBUTE_CREATE

public static final java.lang.String ATTRIBUTE_CREATE

Constant for parsing activity XML - create new resource

See Also:

Constant Field Values

HEADER

public static final java.lang.String HEADER

Header for the XML representation of a set of resources.

See Also:

Constant Field Values

FOOTER

public static final java.lang.String FOOTER

Footer for the XML representation of a set of resources.

See Also:

Constant Field Values

mResources

private org.w3c.dom.NodeList mResources

Resources for bulk loading if they are included in the request

mCurrentResource

private int mCurrentResource

Number of the resource we are currently processing

mInput

private BlockReader mInput

Input stream from another activity, providing the resources

mCollection

private org.xmldb.api.base.Collection mCollection

Collection into which the resources will be loaded

mCreateCollectionIfNotExists

private boolean mCreateCollectionIfNotExists

should we create a new collection if it doesn't exist?

Constructor Detail

XMLBulkLoadActivity

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

Constructs an XMLBulkLoad 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

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 XMLDBActivity

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 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 XMLDBActivity

addDocument

private void addDocument(org.w3c.dom.Element element)
                  throws ActivityExecutionException

Add a resource to the current collection.

Parameters:

element - The resource as a DOM object.

Throws:

ActivityExecutionException - If any problem occurs.

resultsToXML

private java.lang.String resultsToXML(int numResources)

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

 <resultCount>N<l/resultCount>
 

Parameters:

numResources - the number of resources in the result count.

Returns:

string representation