org.apache.xpath.jaxp

Class XPathExpressionImpl

public class XPathExpressionImpl extends Object implements XPathExpression

The XPathExpression interface encapsulates a (compiled) XPath expression.

Version: $Revision: 1.1 $

Author: Ramesh Mandava

Method Summary
Object	eval(Object item, QName returnType)
Object	evaluate(Object item, QName returnType) Evaluate the compiled XPath expression in the specified context and return the result as the specified type. See "Evaluation of XPath Expressions" section of JAXP 1.3 spec for context item evaluation, variable, function and QName resolution and return type conversion. If `returnType` is not one of the types defined in XPathConstants, then an `IllegalArgumentException` is thrown. If a `null` value is provided for `item`, an empty document will be used for the context.
String	evaluate(Object item) Evaluate the compiled XPath expression in the specified context and return the result as a `String`. This method calls XPathExpressionImpl with a `returnType` of XPathConstants#STRING. See "Evaluation of XPath Expressions" section of JAXP 1.3 spec for context item evaluation, variable, function and QName resolution and return type conversion. If a `null` value is provided for `item`, an empty document will be used for the context.
Object	evaluate(InputSource source, QName returnType) Evaluate the compiled XPath expression in the context of the specified `InputSource` and return the result as the specified type. This method builds a data model for the InputSource and calls XPathExpressionImpl on the resulting document object. See "Evaluation of XPath Expressions" section of JAXP 1.3 spec for context item evaluation, variable, function and QName resolution and return type conversion. If `returnType` is not one of the types defined in XPathConstants, then an `IllegalArgumentException` is thrown. If `source` or `returnType` is `null`, then a `NullPointerException` is thrown.
String	evaluate(InputSource source) Evaluate the compiled XPath expression in the context of the specified `InputSource` and return the result as a `String`. This method calls XPathExpressionImpl with a `returnType` of XPathConstants#STRING. See "Evaluation of XPath Expressions" section of JAXP 1.3 spec for context item evaluation, variable, function and QName resolution and return type conversion. If `source` is `null`, then a `NullPointerException` is thrown.
void	setXPath(XPath xpath)

Method Detail

eval

public Object eval(Object item, QName returnType)

evaluate

public Object evaluate(Object item, QName returnType)

Evaluate the compiled XPath expression in the specified context and return the result as the specified type.

See "Evaluation of XPath Expressions" section of JAXP 1.3 spec for context item evaluation, variable, function and QName resolution and return type conversion.

If returnType is not one of the types defined in XPathConstants, then an IllegalArgumentException is thrown.

If a null value is provided for item, an empty document will be used for the context. If returnType is null, then a NullPointerException is thrown.

Parameters: item The starting context (node or node list, for example). returnType The desired return type.

Returns: The Object that is the result of evaluating the expression and converting the result to returnType.

Throws: XPathExpressionException If the expression cannot be evaluated. IllegalArgumentException If returnType is not one of the types defined in XPathConstants. NullPointerException If returnType is null.

evaluate

public String evaluate(Object item)

Evaluate the compiled XPath expression in the specified context and return the result as a String.

This method calls XPathExpressionImpl with a returnType of XPathConstants#STRING.

See "Evaluation of XPath Expressions" section of JAXP 1.3 spec for context item evaluation, variable, function and QName resolution and return type conversion.

If a null value is provided for item, an empty document will be used for the context.

Parameters: item The starting context (node or node list, for example).

Returns: The String that is the result of evaluating the expression and converting the result to a String.

Throws: XPathExpressionException If the expression cannot be evaluated.

evaluate

public Object evaluate(InputSource source, QName returnType)

Evaluate the compiled XPath expression in the context of the specified InputSource and return the result as the specified type.

This method builds a data model for the InputSource and calls XPathExpressionImpl on the resulting document object.

See "Evaluation of XPath Expressions" section of JAXP 1.3 spec for context item evaluation, variable, function and QName resolution and return type conversion.

If returnType is not one of the types defined in XPathConstants, then an IllegalArgumentException is thrown.

If source or returnType is null, then a NullPointerException is thrown.

Parameters: source The InputSource of the document to evaluate over. returnType The desired return type.

Returns: The Object that is the result of evaluating the expression and converting the result to returnType.

evaluate

public String evaluate(InputSource source)

Evaluate the compiled XPath expression in the context of the specified InputSource and return the result as a String.

This method calls XPathExpressionImpl with a returnType of XPathConstants#STRING.

See "Evaluation of XPath Expressions" section of JAXP 1.3 spec for context item evaluation, variable, function and QName resolution and return type conversion.

If source is null, then a NullPointerException is thrown.

Parameters: source The InputSource of the document to evaluate over.

Returns: The String that is the result of evaluating the expression and converting the result to a String.

Throws: XPathExpressionException If the expression cannot be evaluated. NullPointerException If source is null.

setXPath

public void setXPath(XPath xpath)