org.jaxen.javabean

Class JavaBeanXPath

java.lang.Object

org.jaxen.BaseXPath

org.jaxen.javabean.JavaBeanXPath

All Implemented Interfaces:

Serializable, XPath

public class JavaBeanXPath
extends BaseXPath

An XPath implementation for JavaBeans.

This is the main entry point for matching an XPath against a JavaBean tree. You create a compiled XPath object, then match it against one or more context nodes using the BaseXPath.selectNodes(Object) method, as in the following example:

 Node node = ...;
 XPath path = new JavaBeanXPath("a/b/c");
 List results = path.selectNodes(node);
 

Version:

$Revision: 1161 $

Author:

bob mcwhirter

See Also:

BaseXPath, Serialized Form

Constructor Summary

Constructors

Constructor and Description
JavaBeanXPath(String xpathExpr) Construct given an XPath expression string.

Method Summary

Methods

Modifier and Type	Method and Description
Object	evaluate(Object node) Evaluate this XPath against a given context.
protected Context	getContext(Object node) Create a Context wrapper for the provided implementation-specific object.

Methods inherited from class org.jaxen.BaseXPath

addNamespace, booleanValueOf, createFunctionContext, createNamespaceContext, createVariableContext, debug, getContextSupport, getFunctionContext, getNamespaceContext, getNavigator, getRootExpr, getVariableContext, numberValueOf, selectNodes, selectNodesForContext, selectSingleNode, selectSingleNodeForContext, setFunctionContext, setNamespaceContext, setVariableContext, stringValueOf, toString, valueOf

Methods inherited from class java.lang.Object

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

Constructor Detail

JavaBeanXPath

public JavaBeanXPath(String xpathExpr)
              throws JaxenException

Construct given an XPath expression string.

Parameters:

xpathExpr - The XPath expression.

Throws:

JaxenException - if there is a syntax error while parsing the expression

Method Detail

getContext

protected Context getContext(Object node)

Description copied from class: BaseXPath

Create a Context wrapper for the provided implementation-specific object.

Overrides:

getContext in class BaseXPath

Parameters:

node - the implementation-specific object to be used as the context

Returns:

a Context wrapper around the object

evaluate

public Object evaluate(Object node)
                throws JaxenException

Description copied from class: BaseXPath

Evaluate this XPath against a given context. The context of evaluation may be any object type the navigator recognizes as a node. The return value is either a String, Double, Boolean, or List of nodes.

When using this method, one must be careful to test the class of the returned object. If the returned object is a list, then the items in this list will be the actual Document, Element, Attribute, etc. objects as defined by the concrete XML object-model implementation, directly from the context document. This method does not return copies of anything, but merely returns references to objects within the source document.

Specified by:

evaluate in interface XPath

Overrides:

evaluate in class BaseXPath

Parameters:

node - the node, node-set or Context object for evaluation. This value can be null.

Returns:

the result of evaluating the XPath expression against the supplied context

Throws:

JaxenException - if an XPath error occurs during expression evaluation