public class XPathImpl extends Object implements XPath
Modifier and Type | Method and Description |
---|---|
XPathExpression |
compile(String expression)
Compile an XPath expression for later evaluation.
|
String |
evaluate(String expression,
InputSource source)
Evaluate an XPath expression in the context of the specified
InputSource
and return the result as a String . |
Object |
evaluate(String expression,
InputSource source,
QName returnType)
Evaluate an XPath expression in the context of the specified
InputSource
and return the result as the specified type. |
String |
evaluate(String expression,
Object item)
Evaluate an XPath expression in the specified context and return the result as a
String . |
Object |
evaluate(String expression,
Object item,
QName returnType)
Evaluate an
XPath expression in the specified context and return the result as the specified type. |
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
XPath to its original configuration. |
void |
setNamespaceContext(NamespaceContext nsContext)
Establishes a namespace context.
|
void |
setXPathFunctionResolver(XPathFunctionResolver resolver)
Establishes a function resolver.
|
void |
setXPathVariableResolver(XPathVariableResolver resolver)
Establishes a variable resolver.
|
public void setXPathVariableResolver(XPathVariableResolver resolver)
Establishes a variable resolver.
setXPathVariableResolver
in interface XPath
resolver
- Variable Resolverpublic XPathVariableResolver getXPathVariableResolver()
Returns the current variable resolver.
getXPathVariableResolver
in interface XPath
public void setXPathFunctionResolver(XPathFunctionResolver resolver)
Establishes a function resolver.
setXPathFunctionResolver
in interface XPath
resolver
- XPath function resolverpublic XPathFunctionResolver getXPathFunctionResolver()
Returns the current function resolver.
getXPathFunctionResolver
in interface XPath
public void setNamespaceContext(NamespaceContext nsContext)
Establishes a namespace context.
setNamespaceContext
in interface XPath
nsContext
- Namespace context to usepublic NamespaceContext getNamespaceContext()
Returns the current namespace context.
getNamespaceContext
in interface XPath
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 in XPathConstants
(
NUMBER
,
STRING
,
BOOLEAN
,
NODE
or
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.
evaluate
in interface XPath
expression
- The XPath expression.item
- The starting context (node or node list, for example).returnType
- The desired return type.Object
of returnType
.XPathExpressionException
- If expression
cannot be evaluated.IllegalArgumentException
- If returnType
is not one of the types defined in XPathConstants
.NullPointerException
- If expression
or returnType
is null
.public String evaluate(String expression, Object item) throws XPathExpressionException
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 a returnType
of
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.
evaluate
in interface XPath
expression
- The XPath expression.item
- The starting context (node or node list, for example).String
that is the result of evaluating the expression and
converting the result to a String
.XPathExpressionException
- If expression
cannot be evaluated.NullPointerException
- If expression
is null
.public XPathExpression compile(String expression) throws XPathExpressionException
Compile an XPath expression for later evaluation.
If expression
contains any XPathFunction
s,
they must be available via the XPathFunctionResolver
.
An XPathExpressionException
will be thrown if the XPathFunction
cannot be resovled with the XPathFunctionResolver
.
If expression
is null
, a NullPointerException
is thrown.
compile
in interface XPath
expression
- The XPath expression.XPathExpressionException
- If expression
cannot be compiled.NullPointerException
- If expression
is null
.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 calls
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 XPathConstants
,
then an IllegalArgumentException
is thrown.
If expression
, source
or returnType
is null
,
then a NullPointerException
is thrown.
evaluate
in interface XPath
expression
- The XPath expression.source
- The input source of the document to evaluate over.returnType
- The desired return type.Object
that encapsulates the result of evaluating the expression.XPathExpressionException
- If expression cannot be evaluated.IllegalArgumentException
- If returnType
is not one of the types defined in XPathConstants
.NullPointerException
- If expression
, source
or returnType
is null
.public String evaluate(String expression, InputSource source) throws XPathExpressionException
Evaluate an XPath expression in the context of the specified InputSource
and return the result as a String
.
This method calls evaluate(String expression, InputSource source, QName returnType)
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 expression
or source
is null
,
then a NullPointerException
is thrown.
evaluate
in interface XPath
expression
- The XPath expression.source
- The InputSource
of the document to evaluate over.String
that is the result of evaluating the expression and
converting the result to a String
.XPathExpressionException
- If expression cannot be evaluated.NullPointerException
- If expression
or source
is null
.public void reset()
Reset this XPath
to its original configuration.
XPath
is reset to the same state as when it was created with
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
XPathFunctionResolver
, XPathVariableResolver
or NamespaceContext
Object
s, e.g. Object.equals(Object obj)
.
It is guaranteed to have a functionally equal XPathFunctionResolver
,
XPathVariableResolver
and NamespaceContext
.
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