Class XPathImpl
- All Implemented Interfaces:
XPath
- Version:
- $Revision: 1225280 $
- Author:
- Ramesh Mandava
-
Method Summary
Modifier and TypeMethodDescriptionCompile an XPath expression for later evaluation.Evaluate an XPath expression in the specified context and return the result as aString
.Evaluate anXPath
expression in the specified context and return the result as the specified type.evaluate
(String expression, InputSource source) Evaluate an XPath expression in the context of the specifiedInputSource
and return the result as aString
.evaluate
(String expression, InputSource source, QName returnType) Evaluate an XPath expression in the context of the specifiedInputSource
and return the result as the specified type.Returns the current namespace context.Returns the current function resolver.Returns the current variable resolver.void
reset()
Reset thisXPath
to its original configuration.void
setNamespaceContext
(NamespaceContext nsContext) Establishes a namespace context.void
Establishes a function resolver.void
Establishes a variable resolver.Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface javax.xml.xpath.XPath
evaluateExpression, evaluateExpression, evaluateExpression, evaluateExpression
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Method Details
-
setXPathVariableResolver
Establishes a variable resolver.
- Specified by:
setXPathVariableResolver
in interfaceXPath
- Parameters:
resolver
- Variable Resolver
-
getXPathVariableResolver
Returns the current variable resolver.
- Specified by:
getXPathVariableResolver
in interfaceXPath
- Returns:
- Current variable resolver
-
setXPathFunctionResolver
Establishes a function resolver.
- Specified by:
setXPathFunctionResolver
in interfaceXPath
- Parameters:
resolver
- XPath function resolver
-
getXPathFunctionResolver
Returns the current function resolver.
- Specified by:
getXPathFunctionResolver
in interfaceXPath
- Returns:
- Current function resolver
-
setNamespaceContext
Establishes a namespace context.
- Specified by:
setNamespaceContext
in interfaceXPath
- Parameters:
nsContext
- Namespace context to use
-
getNamespaceContext
Returns the current namespace context.
- Specified by:
getNamespaceContext
in interfaceXPath
- Returns:
- Current Namespace context
-
evaluate
public Object evaluate(String expression, Object item, QName returnType) throws XPathExpressionException Evaluate an
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 inXPathConstants
(NUMBER
,STRING
,BOOLEAN
,NODE
orNODESET
) then anIllegalArgumentException
is thrown.If a
null
value is provided foritem
, an empty document will be used for the context. Ifexpression
orreturnType
isnull
, then aNullPointerException
is thrown.- Specified by:
evaluate
in interfaceXPath
- Parameters:
expression
- The XPath expression.item
- The starting context (node or node list, for example).returnType
- The desired return type.- Returns:
- Result of evaluating an XPath expression as an
Object
ofreturnType
. - Throws:
XPathExpressionException
- Ifexpression
cannot be evaluated.IllegalArgumentException
- IfreturnType
is not one of the types defined inXPathConstants
.NullPointerException
- Ifexpression
orreturnType
isnull
.
-
evaluate
Evaluate an XPath expression in the specified context and return the result as a
String
.This method calls
evaluate(String expression, Object item, QName returnType)
with areturnType
ofXPathConstants.STRING
.See "Evaluation of XPath Expressions" of JAXP 1.3 spec for context item evaluation, variable, function and QName resolution and return type conversion.
If a
null
value is provided foritem
, an empty document will be used for the context. Ifexpression
isnull
, then aNullPointerException
is thrown.- Specified by:
evaluate
in interfaceXPath
- Parameters:
expression
- The XPath expression.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 aString
. - Throws:
XPathExpressionException
- Ifexpression
cannot be evaluated.NullPointerException
- Ifexpression
isnull
.
-
compile
Compile an XPath expression for later evaluation.
If
expression
contains anyXPathFunction
s, they must be available via theXPathFunctionResolver
. AnXPathExpressionException
will be thrown if theXPathFunction
cannot be resovled with theXPathFunctionResolver
.If
expression
isnull
, aNullPointerException
is thrown.- Specified by:
compile
in interfaceXPath
- Parameters:
expression
- The XPath expression.- Returns:
- Compiled XPath expression.
- Throws:
XPathExpressionException
- Ifexpression
cannot be compiled.NullPointerException
- Ifexpression
isnull
.
-
evaluate
public Object evaluate(String expression, InputSource source, QName returnType) throws XPathExpressionException Evaluate an 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 callsevaluate(String expression, Object item, QName returnType)
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 inXPathConstants
, then anIllegalArgumentException
is thrown.If
expression
,source
orreturnType
isnull
, then aNullPointerException
is thrown.- Specified by:
evaluate
in interfaceXPath
- Parameters:
expression
- The XPath expression.source
- The input source of the document to evaluate over.returnType
- The desired return type.- Returns:
- The
Object
that encapsulates the result of evaluating the expression. - Throws:
XPathExpressionException
- If expression cannot be evaluated.IllegalArgumentException
- IfreturnType
is not one of the types defined inXPathConstants
.NullPointerException
- Ifexpression
,source
orreturnType
isnull
.
-
evaluate
Evaluate an XPath expression in the context of the specified
InputSource
and return the result as aString
.This method calls
evaluate(String expression, InputSource source, QName returnType)
with areturnType
ofXPathConstants.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
expression
orsource
isnull
, then aNullPointerException
is thrown.- Specified by:
evaluate
in interfaceXPath
- Parameters:
expression
- The XPath expression.source
- TheInputSource
of the document to evaluate over.- Returns:
- The
String
that is the result of evaluating the expression and converting the result to aString
. - Throws:
XPathExpressionException
- If expression cannot be evaluated.NullPointerException
- Ifexpression
orsource
isnull
.
-
reset
public void reset()Reset this
XPath
to its original configuration.XPath
is reset to the same state as when it was created withXPathFactory#newXPath()
.reset()
is designed to allow the reuse of existingXPath
s thus saving resources associated with the creation of newXPath
s.The reset
XPath
is not guaranteed to have the sameXPathFunctionResolver
,XPathVariableResolver
orNamespaceContext
Object
s, e.g.Object.equals(Object obj)
. It is guaranteed to have a functionally equalXPathFunctionResolver
,XPathVariableResolver
andNamespaceContext
.
-