Package javax.xml.xpath

Interface XPathExpression

All Known Implementing Classes:
XPathExpressionImpl
public interface XPathExpression

XPathExpression provides access to compiled XPath expressions.

Evaluation of XPath Expressions.
context If a request is made to evaluate the expression in the absence of a context item, an empty document node will be used for the context. For the purposes of evaluating XPath expressions, a DocumentFragment is treated like a Document node.
variables If the expression contains a variable reference, its value will be found through the XPathVariableResolver. An XPathExpressionException is raised if the variable resolver is undefined or the resolver returns null for the variable. The value of a variable must be immutable through the course of any single evaluation.
functions If the expression contains a function reference, the function will be found through the XPathFunctionResolver. An XPathExpressionException is raised if the function resolver is undefined or the function resolver returns null for the function.
QNames QNames in the expression are resolved against the XPath namespace context.
result This result of evaluating an expression is converted to an instance of the desired return type. Valid return types are defined in XPathConstants. Conversion to the return type follows XPath conversion rules.
Since:
1.5
Version:
$Revision: 446598 $, $Date: 2006-09-15 05:55:40 -0700 (Fri, 15 Sep 2006) $
Author:
Norman Walsh, Jeff Suttor
See Also:
XML Path Language (XPath) Version 1.0, Expressions

  • Method Summary

    Modifier and Type Method Description
    String evaluate​(Object item)
    Evaluate the compiled XPath expression in the specified context and return the result as a String.
    Object evaluate​(Object item, QName returnType)
    Evaluate the compiled XPath expression in the specified context and return the result as the specified type.
    String evaluate​(InputSource source)
    Evaluate the compiled XPath expression in the context of the specified InputSource and return the result as a String.
    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.