org.apache.xpath.jaxp
public class XPathImpl extends Object implements XPath
Version: $Revision: 1.1 $
Method Summary | |
---|---|
XPathExpression | compile(String expression) Compile an XPath expression for later evaluation. If |
Object | evaluate(String expression, Object item, QName returnType) Evaluate an See "Evaluation of XPath Expressions" section of JAXP 1.3 spec
for context item evaluation,
variable, function and If If a |
String | evaluate(String expression, Object item) Evaluate an XPath expression in the specified context and return the result as a This method calls {@link #evaluate(String expression, Object item, QName returnType)} with a 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 |
Object | evaluate(String expression, InputSource source, QName returnType) Evaluate an XPath expression in the context of the specified This method builds a data model for the {@link InputSource} and calls {@link #evaluate(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 If |
String | evaluate(String expression, InputSource source) Evaluate an XPath expression in the context of the specified This method calls {@link #evaluate(String expression, InputSource source, QName returnType)} with a
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 |
NamespaceContext | getNamespaceContext() Returns the current namespace context. |
XPathFunctionResolver | getXPathFunctionResolver() Returns the current function resolver. |
XPathVariableResolver | getXPathVariableResolver() Returns the current variable resolver. |
void | reset() Reset this
|
void | setNamespaceContext(NamespaceContext nsContext) Establishes a namespace context. |
void | setXPathFunctionResolver(XPathFunctionResolver resolver) Establishes a function resolver. |
void | setXPathVariableResolver(XPathVariableResolver resolver) Establishes a variable resolver. |
Compile an XPath expression for later evaluation.
If expression
contains any {@link XPathFunction}s,
they must be available via the {@link XPathFunctionResolver}.
An {@link XPathExpressionException} will be thrown if the XPathFunction
cannot be resovled with the XPathFunctionResolver
.
If expression
is null
, a NullPointerException
is thrown.
Parameters: expression The XPath expression.
Returns: Compiled XPath expression.
Throws: XPathExpressionException If expression
cannot be compiled. NullPointerException If expression
is null
.
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 in {@link XPathConstants} (
{@link XPathConstants#NUMBER NUMBER},
{@link XPathConstants#STRING STRING},
{@link XPathConstants#BOOLEAN BOOLEAN},
{@link XPathConstants#NODE NODE} or
{@link XPathConstants#NODESET NODESET})
then an IllegalArgumentException
is thrown.
If a null
value is provided for
item
, an empty document will be used for the
context.
If expression
or returnType
is null
, then a
NullPointerException
is thrown.
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
of returnType
.
Throws: XPathExpressionException If expression
cannot be evaluated. IllegalArgumentException If returnType
is not one of the types defined in {@link XPathConstants}. NullPointerException If expression
or returnType
is null
.
Evaluate an XPath expression in the specified context and return the result as a String
.
This method calls {@link #evaluate(String expression, Object item, QName returnType)} with a returnType
of
{@link XPathConstants#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 for
item
, an empty document will be used for the
context.
If expression
is null
, then a NullPointerException
is thrown.
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 a String
.
Throws: XPathExpressionException If expression
cannot be evaluated. NullPointerException If expression
is null
.
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 {@link InputSource} and calls {@link #evaluate(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 in {@link XPathConstants},
then an IllegalArgumentException
is thrown.
If expression
, source
or returnType
is null
,
then a NullPointerException
is thrown.
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 If returnType
is not one of the types defined in {@link XPathConstants}. NullPointerException If expression
, source
or returnType
is null
.
Evaluate an XPath expression in the context of the specified InputSource
and return the result as a String
.
This method calls {@link #evaluate(String expression, InputSource source, QName returnType)} with a
returnType
of {@link 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 expression
or source
is null
,
then a NullPointerException
is thrown.
Parameters: expression The XPath expression. 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 expression cannot be evaluated. NullPointerException If expression
or source
is null
.
Returns the current namespace context.
Returns: Current Namespace context
Returns the current function resolver.
Returns: Current function resolver
Returns the current variable resolver.
Returns: Current variable resolver
Reset this XPath
to its original configuration.
XPath
is reset to the same state as when it was created with
{@link XPathFactory#newXPath()}.
reset()
is designed to allow the reuse of existing XPath
s
thus saving resources associated with the creation of new XPath
s.
The reset XPath
is not guaranteed to have the same
{@link XPathFunctionResolver}, {@link XPathVariableResolver}
or {@link NamespaceContext} Object
s, e.g. {@link Object#equals(Object obj)}.
It is guaranteed to have a functionally equal XPathFunctionResolver
,
XPathVariableResolver
and NamespaceContext
.
Establishes a namespace context.
Parameters: nsContext Namespace context to use
Establishes a function resolver.
Parameters: resolver XPath function resolver
Establishes a variable resolver.
Parameters: resolver Variable Resolver