uk.org.ogsadai.client.toolkit.activity.xmldb
Class XPathQuery

java.lang.Object
  |
  +--uk.org.ogsadai.client.toolkit.activity.RequestComponent
        |
        +--uk.org.ogsadai.client.toolkit.activity.Activity
              |
              +--uk.org.ogsadai.client.toolkit.activity.xmldb.XPathQuery

public class XPathQuery

extends Activity

This activity queries a resource/collection exposed by an XMLDB data service resource using an XPath expression.

It has no input and one output - the query result in XML. The format of the output is OGSA-DAI specific XML. For example:

<resourceSet>
<resource>
<someMatchingResource
xmlns:src="http://xml.apache.org/xindice/Query"
src:col="someCollection" src:key="someKey">
<someElt name="someAttribute"/>
<someElt name="someAttribute"/>
</someMatchingResource>
</resource>
</resourceSet>

Author:

The OGSA-DAI Project Team

Field Summary

private static java.lang.String	COPYRIGHT_NOTICE Copyright statement
private java.lang.String	mCollectionName Name of collection to query
private java.lang.String	mExpression XPath expression
private java.util.Map	mNamespaces Namespace bindings used in the XPath expression
private java.lang.String	mResourceName Name of resource to query

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

Fields inherited from class uk.org.ogsadai.client.toolkit.activity.RequestComponent

Constructor Summary

XPathQuery()
Constructs an XPath query request.

XPathQuery(java.lang.String expression)
Constructs a request to query a resource/collection using XPath.

Method Summary

protected java.lang.String	generateXML() Generates the XML representing the activity.
ActivityOutput	getOutput() Gets the activity's only output - the XPath query result.
org.xmldb.api.base.ResourceSet	getResourceSet() Get the results of the query as a ResourceSet.
void	setCollectionName(java.lang.String collectionName) Set the collection name.
void	setExpression(java.lang.String expression) Set the XPath expression.
void	setNamespaceBinding(java.lang.String prefix, java.lang.String url) Add a binding from a namespace prefix used within the XPath query to a namespace URL.
void	setNamespaceBindings(java.util.Map bindings) Add a collection of bindings from namespace prefixes used within the XPath query to namespace URLs.
void	setResourceName(java.lang.String resourceName) Set the resource name.

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

addInput, addOutput, addOutputs, getDataResourceID, getInputParameters, getOutputParameters, getOutputs, replaceSpecialCharacters, setDataResourceID, setInput

Methods inherited from class uk.org.ogsadai.client.toolkit.activity.RequestComponent

getDataService, getName, getSession, setDataService, setSession

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

mExpression

private java.lang.String mExpression

XPath expression

mResourceName

private java.lang.String mResourceName

Name of resource to query

mCollectionName

private java.lang.String mCollectionName

Name of collection to query

mNamespaces

private java.util.Map mNamespaces

Namespace bindings used in the XPath expression

Constructor Detail

XPathQuery

public XPathQuery()

Constructs an XPath query request. The query expression must be set using setExpression All resources in the base collection and its sub-collections will be queried.

XPathQuery

public XPathQuery(java.lang.String expression)

Constructs a request to query a resource/collection using XPath. All resources in the base collection and its sub-collections will be queried.

Parameters:

expression - XPath query expression.

Throws:

java.lang.IllegalArgumentException - If expression is null

Method Detail

setExpression

public void setExpression(java.lang.String expression)

Set the XPath expression.

Parameters:

expression - XPath query expression.

Throws:

java.lang.IllegalArgumentException - If expression is null

setResourceName

public void setResourceName(java.lang.String resourceName)

Set the resource name. The query will be executed on this resource. If this is set to null then the query will be executed on all the resources in the selected collection.

Parameters:

resourceName - The name of the resource or null.

setCollectionName

public void setCollectionName(java.lang.String collectionName)

Set the collection name. The query will be executed within this collection. If this is set to null then the query will be executed within the base collection.

Parameters:

collectionName - The name of the collection or null.

setNamespaceBinding

public void setNamespaceBinding(java.lang.String prefix,
                                java.lang.String url)

Add a binding from a namespace prefix used within the XPath query to a namespace URL.

Parameters:

prefix - A namespace prefix.

url - A legal URL e.g. http://www.org/test

Throws:

java.lang.IllegalArgumentException - If prefix or url are null or url is not a legal URL.

setNamespaceBindings

public void setNamespaceBindings(java.util.Map bindings)

Add a collection of bindings from namespace prefixes used within the XPath query to namespace URLs.

Parameters:

bindings - A collection of mappings from prefix strings to URL strings.

Throws:

java.lang.IllegalArgumentException - If bindings is null or contains entries whose prefix or URL are null or whose URLs are not legal.

See Also:

If prefix or url are null or url is not a legal URL.

getOutput

public ActivityOutput getOutput()

Gets the activity's only output - the XPath query result.

Returns:

the activity output.

getResourceSet

public org.xmldb.api.base.ResourceSet getResourceSet()
                                              throws NoActivityOutputException,
                                                     DataFormatException

Get the results of the query as a ResourceSet.

Returns:

ResourceSet.

Throws:

NoActivityOutputException - if there is no output data or the data has not yet been processed to this output or the activity that generates this output has not yet been executed.

DataFormatException - if the output from the activity cannot be parsed into a ResourceSet.

generateXML

protected java.lang.String generateXML()

Description copied from class: RequestComponent

Generates the XML representing the activity. This XML can then be inserted into a perform document that is sent to a data service.

Specified by:

generateXML in class Activity

Returns:

the XML for the activity