Added in API level 8

Summary: Constants | Protected Ctors | Methods | Inherited Methods

XPathFactory

public abstract class XPathFactory
extends Object

java.lang.Object
↳	javax.xml.xpath.XPathFactory

An XPathFactory instance can be used to create XPath objects.

See newInstance(java.lang.String) for lookup mechanism.

Summary

Constants
`String`	`DEFAULT_OBJECT_MODEL_URI` Default Object Model URI.
`String`	`DEFAULT_PROPERTY_NAME` The default property name according to the JAXP spec.

Constants

String

DEFAULT_OBJECT_MODEL_URI

Default Object Model URI.

String

DEFAULT_PROPERTY_NAME

The default property name according to the JAXP spec.

Protected constructors
`XPathFactory()` Protected constructor as `newInstance()`, `newInstance(java.lang.String)` or `newInstance(java.lang.String, java.lang.String, java.lang.ClassLoader)` should be used to create a new instance of an `XPathFactory`.

Protected constructors


      XPathFactory()

Protected constructor as newInstance(), newInstance(java.lang.String) or newInstance(java.lang.String, java.lang.String, java.lang.ClassLoader) should be used to create a new instance of an XPathFactory.

Public methods
`abstract boolean`	`getFeature(String name)` Get the state of the named feature.
`abstract boolean`	`isObjectModelSupported(String objectModel)` Is specified object model supported by this `XPathFactory`?
`static final XPathFactory`	`newInstance()` Get a new `XPathFactory` instance using the default object model, `DEFAULT_OBJECT_MODEL_URI`, the W3C DOM.
`static XPathFactory`	`newInstance(String uri, String factoryClassName, ClassLoader classLoader)`
`static final XPathFactory`	`newInstance(String uri)` Get a new `XPathFactory` instance using the specified object model.
`abstract XPath`	`newXPath()` Return a new `XPath` using the underlying object model determined when the `XPathFactory` was instantiated.
`abstract void`	`setFeature(String name, boolean value)` Set a feature for this `XPathFactory` and `XPath`s created by this factory.
`abstract void`	`setXPathFunctionResolver(XPathFunctionResolver resolver)` Establish a default function resolver.
`abstract void`	`setXPathVariableResolver(XPathVariableResolver resolver)` Establish a default variable resolver.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Constants

DEFAULT_OBJECT_MODEL_URI

Added in API level 8

public static final String DEFAULT_OBJECT_MODEL_URI

Default Object Model URI.

Constant Value: "http://java.sun.com/jaxp/xpath/dom"

DEFAULT_PROPERTY_NAME

Added in API level 8

public static final String DEFAULT_PROPERTY_NAME

The default property name according to the JAXP spec.

Constant Value: "javax.xml.xpath.XPathFactory"

Protected constructors

XPathFactory

Added in API level 8

protected XPathFactory ()

Public methods

getFeature

Added in API level 8

public abstract boolean getFeature (String name)

Get the state of the named feature.

Feature names are fully qualified 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`	`String`: Feature name.

Returns
`boolean`	State of the named feature.

Throws
`XPathFactoryConfigurationException`	if this `XPathFactory` or the `XPath`s it creates cannot support this feature.
`NullPointerException`	if `name` is `null`.

isObjectModelSupported

Added in API level 8

public abstract boolean isObjectModelSupported (String objectModel)

Is specified object model supported by this XPathFactory?

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

Returns
`boolean`	`true` if `XPathFactory` supports `objectModel`, else `false`.

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

newInstance

Added in API level 8

public static final XPathFactory 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
`XPathFactory`	Instance of an `XPathFactory`.

newInstance

Added in API level 8

public static XPathFactory newInstance (String uri, 
                String factoryClassName, 
                ClassLoader classLoader)

Parameters
`uri`	`String`
`factoryClassName`	`String`
`classLoader`	`ClassLoader`

Returns
`XPathFactory`	Instance of an `XPathFactory`.

Throws
`XPathFactoryConfigurationException`	If the specified object model is unavailable.
`NullPointerException`	If `uri` is `null`.
`IllegalArgumentException`	If `uri.length() == 0`.

newInstance

Added in API level 8

public static final XPathFactory newInstance (String uri)

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:

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.
${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.
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:
```
       isObjectModelSupported(java.lang.String)
     
```
The first service provider found in class loader order that supports the specified object model is returned.
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 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`	`String`: 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
`XPathFactory`	Instance of an `XPathFactory`.

Throws
`XPathFactoryConfigurationException`	If the specified object model is unavailable.
`NullPointerException`	If `uri` is `null`.
`IllegalArgumentException`	If `uri.length() == 0`.

newXPath

Added in API level 8

public abstract XPath newXPath ()

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

Returns
`XPath`	New instance of an `XPath`.

setFeature

Added in API level 8

public abstract void setFeature (String name, 
                boolean value)

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

All implementations are required to support the XMLConstants.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`	`String`: Feature name.
`value`	`boolean`: Is feature state `true` or `false`.

Throws
`XPathFactoryConfigurationException`	if this `XPathFactory` or the `XPath`s it creates cannot support this feature.
`NullPointerException`	if `name` is `null`.

setXPathFunctionResolver

Added in API level 8

public abstract void setXPathFunctionResolver (XPathFunctionResolver resolver)

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`	`XPathFunctionResolver`: XPath function resolver.

Throws
`NullPointerException`	If `resolver` is `null`.

setXPathVariableResolver

Added in API level 8

public abstract void setXPathVariableResolver (XPathVariableResolver resolver)

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`	`XPathVariableResolver`: Variable resolver.

Throws
`NullPointerException`	If `resolver` is `null`.