An XPathFactory
instance can be used to create
XPath
objects.
See newInstance(String uri)
for lookup mechanism.
The XPathFactory
class is not thread-safe. In other words,
it is the application's responsibility to ensure that at most
one thread is using a XPathFactory
object at any
given moment. Implementations are encouraged to mark methods
as synchronized
to protect themselves from broken clients.
XPathFactory
is not re-entrant. While one of the
newInstance
methods is being invoked, applications
may not attempt to recursively invoke a newInstance
method,
even from the same thread.
- Since:
- 1.5
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Field Summary
-
Constructor Summary
ModifierConstructorDescriptionprotected
Protected constructor asnewInstance()
ornewInstance(String uri)
ornewInstance(String uri, String factoryClassName, ClassLoader classLoader)
should be used to create a new instance of anXPathFactory
. -
Method Summary
Modifier and TypeMethodDescriptionabstract boolean
getFeature
(String name) Get the state of the named feature.getProperty
(String name) Returns the value of the specified property.abstract boolean
isObjectModelSupported
(String objectModel) Is specified object model supported by thisXPathFactory
?static XPathFactory
Creates a new instance of theXPathFactory
builtin system-default implementation.static XPathFactory
Get a newXPathFactory
instance using the default object model,DEFAULT_OBJECT_MODEL_URI
, the W3C DOM.static XPathFactory
newInstance
(String uri) Obtains a newXPathFactory
instance using the specified object model.static XPathFactory
newInstance
(String uri, String factoryClassName, ClassLoader classLoader) Obtain a new instance of aXPathFactory
from a factory class name.abstract XPath
newXPath()
Return a newXPath
using the underlying object model determined when theXPathFactory
was instantiated.abstract void
setFeature
(String name, boolean value) Sets a feature for thisXPathFactory
.void
setProperty
(String name, String value) Sets a property for thisXPathFactory
.abstract void
Establish a default function resolver.abstract void
Establish a default variable resolver.
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Field Details
-
DEFAULT_PROPERTY_NAME
The default property name according to the JAXP spec.
- See Also:
-
DEFAULT_OBJECT_MODEL_URI
-
-
Constructor Details
-
XPathFactory
protected XPathFactory()Protected constructor as
newInstance()
ornewInstance(String uri)
ornewInstance(String uri, String factoryClassName, ClassLoader classLoader)
should be used to create a new instance of anXPathFactory
.
-
-
Method Details
-
newDefaultInstance
Creates a new instance of theXPathFactory
builtin system-default implementation.- Implementation Requirements:
- The
XPathFactory
builtin system-default implementation is only required to support thedefault object model
, the W3C DOM, but may support additional object models. - Returns:
- A new instance of the
XPathFactory
builtin system-default implementation. - Since:
- 9
-
newInstance
Get a new
XPathFactory
instance using the default object model,DEFAULT_OBJECT_MODEL_URI
, the W3C DOM.This method is functionally equivalent to:
newInstance(DEFAULT_OBJECT_MODEL_URI)
Since the implementation for the W3C DOM is always available, this method will never fail.
- Returns:
- Instance of an
XPathFactory
. - Throws:
RuntimeException
- When there is a failure in creating anXPathFactory
for the default object model.
-
newInstance
Obtains a newXPathFactory
instance using the specified object model. This method uses the JAXP Lookup Mechanism to determine and load theXPathFactory
implementation that supports the specified object model.Tip for Trouble-shooting:
See
Properties.load(java.io.InputStream)
for exactly how a property file is parsed. In particular, colons ':' need to be escaped in a property file, so make sure the URIs are properly escaped in it. For example:http\://java.sun.com/jaxp/xpath/dom=org.acme.DomXPathFactory
- Parameters:
uri
- Identifies the underlying object model. The specification only defines the URIDEFAULT_OBJECT_MODEL_URI
,http://java.sun.com/jaxp/xpath/dom
for the W3C DOM, the org.w3c.dom package, and implementations are free to introduce other URIs for other object models.- Returns:
- Instance of an
XPathFactory
. - Throws:
XPathFactoryConfigurationException
- If the specified object model is unavailable, or if there is a configuration error.NullPointerException
- Ifuri
isnull
.IllegalArgumentException
- Ifuri
isnull
oruri.length() == 0
.
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newInstance
public static XPathFactory newInstance(String uri, String factoryClassName, ClassLoader classLoader) throws XPathFactoryConfigurationException Obtain a new instance of a
XPathFactory
from a factory class name.XPathFactory
is returned if specified factory class supports the specified object model. This function is useful when there are multiple providers in the classpath. It gives more control to the application as it can specify which provider should be loaded.Tip for Trouble-shooting
Setting the
jaxp.debug
system property will cause this method to print a lot of debug messages toSystem.err
about what it is doing and where it is looking at.If you have problems try:
java -Djaxp.debug=1 YourProgram ....
- Parameters:
uri
- Identifies the underlying object model. The specification only defines the URIDEFAULT_OBJECT_MODEL_URI
,http://java.sun.com/jaxp/xpath/dom
for the W3C DOM, the org.w3c.dom package, and implementations are free to introduce other URIs for other object models.factoryClassName
- fully qualified factory class name that provides implementation ofjavax.xml.xpath.XPathFactory
.classLoader
-ClassLoader
used to load the factory class. Ifnull
currentThread
's context classLoader is used to load the factory class.- Returns:
- New instance of a
XPathFactory
- Throws:
XPathFactoryConfigurationException
- iffactoryClassName
isnull
, or the factory class cannot be loaded, instantiated or the factory class does not support the object model specified in theuri
parameter.NullPointerException
- Ifuri
isnull
.IllegalArgumentException
- Ifuri
isnull
oruri.length() == 0
.- Since:
- 1.6
- See Also:
-
isObjectModelSupported
Is specified object model supported by this
XPathFactory
?- Parameters:
objectModel
- Specifies the object model which the returnedXPathFactory
will understand.- Returns:
true
ifXPathFactory
supportsobjectModel
, elsefalse
.- Throws:
NullPointerException
- IfobjectModel
isnull
.IllegalArgumentException
- IfobjectModel.length() == 0
.
-
setFeature
public abstract void setFeature(String name, boolean value) throws XPathFactoryConfigurationException Sets a feature for thisXPathFactory
. The feature applies toXPath
objects that theXPathFactory
creates. It has no impact onXPath
objects that are already created.Feature names are fully qualified
URI
s. Implementations may define their own features. AnXPathFactoryConfigurationException
is thrown if thisXPathFactory
or theXPath
s it creates cannot support the feature. It is possible for anXPathFactory
to expose a feature value but be unable to change its state.All implementations are required to support the
XMLConstants.FEATURE_SECURE_PROCESSING
feature. When the feature istrue
, any reference to an external function is an error. Under these conditions, the implementation must not call theXPathFunctionResolver
and must throw anXPathFunctionException
.- Parameters:
name
- Feature name.value
- Is feature statetrue
orfalse
.- Throws:
XPathFactoryConfigurationException
- if thisXPathFactory
or theXPath
s it creates cannot support this feature.NullPointerException
- ifname
isnull
.
-
getFeature
Get the state of the named feature.
Feature names are fully qualified
URI
s. Implementations may define their own features. AnXPathFactoryConfigurationException
is thrown if thisXPathFactory
or theXPath
s it creates cannot support the feature. It is possible for anXPathFactory
to expose a feature value but be unable to change its state.- Parameters:
name
- Feature name.- Returns:
- State of the named feature.
- Throws:
XPathFactoryConfigurationException
- if thisXPathFactory
or theXPath
s it creates cannot support this feature.NullPointerException
- ifname
isnull
.
-
setXPathVariableResolver
Establish a default variable resolver.
Any
XPath
objects constructed from this factory will use the specified resolver by default.A
NullPointerException
is thrown ifresolver
isnull
.- Parameters:
resolver
- Variable resolver.- Throws:
NullPointerException
- Ifresolver
isnull
.
-
setXPathFunctionResolver
Establish a default function resolver.
Any
XPath
objects constructed from this factory will use the specified resolver by default.A
NullPointerException
is thrown ifresolver
isnull
.- Parameters:
resolver
- XPath function resolver.- Throws:
NullPointerException
- Ifresolver
isnull
.
-
newXPath
Return a new
XPath
using the underlying object model determined when theXPathFactory
was instantiated.- Returns:
- New instance of an
XPath
.
-
setProperty
Sets a property for thisXPathFactory
. The property applies toXPath
objects that theXPathFactory
creates. It has no impact onXPath
objects that are already created.A property can either be defined in this
XPathFactory
, or by the underlying implementation.- Implementation Requirements:
- The default implementation throws
UnsupportedOperationException
. - Parameters:
name
- the property namevalue
- the value for the property- Throws:
IllegalArgumentException
- if the property name is not recognized, or the value can not be assignedUnsupportedOperationException
- if the implementation does not support the methodNullPointerException
- if thename
isnull
- Since:
- 18
-
getProperty
Returns the value of the specified property.- Implementation Requirements:
- The default implementation throws
UnsupportedOperationException
. - Parameters:
name
- the property name- Returns:
- the value of the property.
- Throws:
IllegalArgumentException
- if the property name is not recognizedUnsupportedOperationException
- if the implementation does not support the methodNullPointerException
- if thename
isnull
- Since:
- 18
-