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 SummaryFields
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Constructor SummaryConstructorsModifierConstructorDescriptionprotectedProtected constructor asnewInstance()ornewInstance(String uri)ornewInstance(String uri, String factoryClassName, ClassLoader classLoader)should be used to create a new instance of anXPathFactory.
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Method SummaryModifier and TypeMethodDescriptionabstract booleangetFeature(String name) Get the state of the named feature.getProperty(String name) Returns the value of the specified property.abstract booleanisObjectModelSupported(String objectModel) Is specified object model supported by thisXPathFactory?static XPathFactoryCreates a new instance of theXPathFactorybuiltin system-default implementation.static XPathFactoryGet a newXPathFactoryinstance using the default object model,DEFAULT_OBJECT_MODEL_URI, the W3C DOM.static XPathFactorynewInstance(String uri) Obtains a newXPathFactoryinstance using the specified object model.static XPathFactorynewInstance(String uri, String factoryClassName, ClassLoader classLoader) Obtain a new instance of aXPathFactoryfrom a factory class name.abstract XPathnewXPath()Return a newXPathusing the underlying object model determined when theXPathFactorywas instantiated.abstract voidsetFeature(String name, boolean value) Sets a feature for thisXPathFactory.voidsetProperty(String name, String value) Sets a property for thisXPathFactory.abstract voidEstablish a default function resolver.abstract voidEstablish a default variable resolver.
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Field Details- 
DEFAULT_PROPERTY_NAMEThe default property name according to the JAXP spec. - See Also:
 
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DEFAULT_OBJECT_MODEL_URIDefault Object Model URI. - See Also:
 
 
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Constructor Details- 
XPathFactoryprotected 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.
 
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Method Details- 
newDefaultInstanceCreates a new instance of theXPathFactorybuiltin system-default implementation.- Implementation Requirements:
- The XPathFactorybuiltin 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 XPathFactorybuiltin system-default implementation.
- Since:
- 9
 
- 
newInstanceGet a new XPathFactoryinstance 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 an- XPathFactoryfor the default object model.
 
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newInstanceObtains a newXPathFactoryinstance using the specified object model. This method uses the JAXP Lookup Mechanism to determine and load theXPathFactoryimplementation 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 URI- DEFAULT_OBJECT_MODEL_URI,- http://java.sun.com/jaxp/xpath/domfor 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- If- uriis- null.
- IllegalArgumentException- If- uriis- nullor- uri.length() == 0.
 
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newInstancepublic static XPathFactory newInstance(String uri, String factoryClassName, ClassLoader classLoader) throws XPathFactoryConfigurationException Obtain a new instance of a XPathFactoryfrom a factory class name.XPathFactoryis 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-shootingSetting the jaxp.debugsystem property will cause this method to print a lot of debug messages toSystem.errabout 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 URI- DEFAULT_OBJECT_MODEL_URI,- http://java.sun.com/jaxp/xpath/domfor 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 of- javax.xml.xpath.XPathFactory.
- classLoader-- ClassLoaderused to load the factory class. If- nullcurrent- Thread's context classLoader is used to load the factory class.
- Returns:
- New instance of a XPathFactory
- Throws:
- XPathFactoryConfigurationException- if- factoryClassNameis- null, or the factory class cannot be loaded, instantiated or the factory class does not support the object model specified in the- uriparameter.
- NullPointerException- If- uriis- null.
- IllegalArgumentException- If- uriis- nullor- uri.length() == 0.
- Since:
- 1.6
- See Also:
 
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isObjectModelSupportedIs specified object model supported by this XPathFactory?- Parameters:
- objectModel- Specifies the object model which the returned- XPathFactorywill understand.
- Returns:
- trueif- XPathFactorysupports- objectModel, else- false.
- Throws:
- NullPointerException- If- objectModelis- null.
- IllegalArgumentException- If- objectModel.length() == 0.
 
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setFeaturepublic abstract void setFeature(String name, boolean value) throws XPathFactoryConfigurationException Sets a feature for thisXPathFactory. The feature applies toXPathobjects that theXPathFactorycreates. It has no impact onXPathobjects that are already created.Feature names are fully qualified URIs. Implementations may define their own features. AnXPathFactoryConfigurationExceptionis thrown if thisXPathFactoryor theXPaths it creates cannot support the feature. It is possible for anXPathFactoryto expose a feature value but be unable to change its state.All implementations are required to support the XMLConstants.FEATURE_SECURE_PROCESSINGfeature. When the feature istrue, any reference to an external function is an error. Under these conditions, the implementation must not call theXPathFunctionResolverand must throw anXPathFunctionException.- Parameters:
- name- Feature name.
- value- Is feature state- trueor- false.
- Throws:
- XPathFactoryConfigurationException- if this- XPathFactoryor the- XPaths it creates cannot support this feature.
- NullPointerException- if- nameis- null.
 
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getFeatureGet the state of the named feature. Feature names are fully qualified URIs. Implementations may define their own features. AnXPathFactoryConfigurationExceptionis thrown if thisXPathFactoryor theXPaths it creates cannot support the feature. It is possible for anXPathFactoryto expose a feature value but be unable to change its state.- Parameters:
- name- Feature name.
- Returns:
- State of the named feature.
- Throws:
- XPathFactoryConfigurationException- if this- XPathFactoryor the- XPaths it creates cannot support this feature.
- NullPointerException- if- nameis- null.
 
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setXPathVariableResolverEstablish a default variable resolver. Any XPathobjects constructed from this factory will use the specified resolver by default.A NullPointerExceptionis thrown ifresolverisnull.- Parameters:
- resolver- Variable resolver.
- Throws:
- NullPointerException- If- resolveris- null.
 
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setXPathFunctionResolverEstablish a default function resolver. Any XPathobjects constructed from this factory will use the specified resolver by default.A NullPointerExceptionis thrown ifresolverisnull.- Parameters:
- resolver- XPath function resolver.
- Throws:
- NullPointerException- If- resolveris- null.
 
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newXPathReturn a new XPathusing the underlying object model determined when theXPathFactorywas instantiated.- Returns:
- New instance of an XPath.
 
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setPropertySets a property for thisXPathFactory. The property applies toXPathobjects that theXPathFactorycreates. It has no impact onXPathobjects 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 name
- value- the value for the property
- Throws:
- IllegalArgumentException- if the property name is not recognized, or the value can not be assigned
- UnsupportedOperationException- if the implementation does not support the method
- NullPointerException- if the- nameis- null
- Since:
- 18
 
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getPropertyReturns 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 recognized
- UnsupportedOperationException- if the implementation does not support the method
- NullPointerException- if the- nameis- null
- Since:
- 18
 
 
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