Class XPathFactory

Default Object Model URI.

The default property name according to the JAXP spec.

Protected constructor as newInstance or XPathFactory should be used to create a new instance of an XPathFactory.

Get the state of the named feature.

Feature names are fully qualified java.net.URIs. Implementations may define their own features. An XPathFactoryConfigurationException is thrown if this XPathFactory or the XPaths it creates cannot support the feature. It is possible for an XPathFactory 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 this XPathFactory or the XPaths it creates cannot support this feature. NullPointerException if name is null.

Is specified object model supported by this XPathFactory?

Parameters: objectModel Specifies the object model which the returned XPathFactory will understand.

Returns: true if XPathFactory supports objectModel, else false.

Throws: NullPointerException If objectModel is null. IllegalArgumentException If objectModel.length() == 0.

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.

Get a new XPathFactory instance using the specified object model.

To find a XPathFactory object, this method looks the following places in the following order where "the class loader" refers to the context class loader:

1. If the system property DEFAULT_PROPERTY_NAME + ":uri" is present, where uri is the parameter to this method, then its value is read as a class name. The method will try to create a new instance of this class by using the class loader, and returns it if it is successfully created.
2. ${java.home}/lib/jaxp.properties is read and the value associated with the key being the system property above is looked for. If present, the value is processed just like above.
3. The class loader is asked for service provider provider-configuration files matching javax.xml.xpath.XPathFactory in the resource directory META-INF/services. See the JAR File Specification for file format and parsing rules. Each potential service provider is required to implement the method:

          XPathFactory
        

   The first service provider found in class loader order that supports the specified object model is returned.
4. Platform default XPathFactory is located in a platform specific way. There must be a platform default XPathFactory for the W3C DOM, i.e. DEFAULT_OBJECT_MODEL_URI.

If everything fails, an XPathFactoryConfigurationException will be thrown.

Tip for Trouble-shooting:

See java.util.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/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. NullPointerException If uri is null. IllegalArgumentException If uri.length() == 0.

Return a new XPath using the underlying object model determined when the XPathFactory was instantiated.

Returns: New instance of an XPath.

Set a feature for this XPathFactory and XPaths created by this factory.

Feature names are fully qualified java.net.URIs. Implementations may define their own features. An XPathFactoryConfigurationException is thrown if this XPathFactory or the XPaths it creates cannot support the feature. It is possible for an XPathFactory to expose a feature value but be unable to change its state.

All implementations are required to support the FEATURE_SECURE_PROCESSING feature. When the feature is true, any reference to an external function is an error. Under these conditions, the implementation must not call the XPathFunctionResolver and must throw an XPathFunctionException.

Parameters: name Feature name. value Is feature state true or false.

Throws: XPathFactoryConfigurationException if this XPathFactory or the XPaths it creates cannot support this feature. NullPointerException if name is null.

Establish a default function resolver.

Any XPath objects constructed from this factory will use the specified resolver by default.

A NullPointerException is thrown if resolver is null.

Parameters: resolver XPath function resolver.

Throws: NullPointerException If resolver is null.

Establish a default variable resolver.

Any XPath objects constructed from this factory will use the specified resolver by default.

A NullPointerException is thrown if resolver is null.

Parameters: resolver Variable resolver.

Throws: NullPointerException If resolver is null.