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| java.lang.Object
 javax.xml.xpath.XPathFactory
| XPathFactory | | abstract public class XPathFactory (Code) | | An XPathFactory instance can be used to create
javax.xml.xpath.XPath objects.
See
XPathFactory.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.
author:
Norman Walsh
author:
Jeff Suttor
version:
$Revision: 1.4 $, $Date: 2005/11/03 19:34:16 $
since:
1.5 |
| Method Summary | |
| abstract public boolean | getFeature(String name)
Get the state of the named feature.
Feature names are fully qualified
java.net.URI s.
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. | | abstract public boolean | isObjectModelSupported(String objectModel)
Is specified object model supported by this XPathFactory?
Parameters:
objectModel - Specifies the object model which the returned XPathFactory will understand. | | final public static XPathFactory | newInstance()
| | final public static 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
XPathFactory.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:
XPathFactory.isObjectModelSupported(String objectModel)
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. | | public static XPathFactory | newInstance(String uri, String factoryClassName, ClassLoader classLoader)
Obtain a new instance of a XPathFactory from a factory class name. | | abstract public XPath | newXPath()
| | abstract public void | setFeature(String name, boolean value)
Set a feature for this XPathFactory and
XPaths created by this factory.
Feature names are fully qualified
java.net.URI s. | | abstract public void | setXPathFunctionResolver(XPathFunctionResolver resolver)
| | abstract public void | setXPathVariableResolver(XPathVariableResolver resolver)
|
| DEFAULT_OBJECT_MODEL_URI | | final public static String DEFAULT_OBJECT_MODEL_URI(Code) | | Default Object Model URI.
|
| DEFAULT_PROPERTY_NAME | | final public static String DEFAULT_PROPERTY_NAME(Code) | | The default property name according to the JAXP spec.
|
| isObjectModelSupported | | abstract public boolean isObjectModelSupported(String objectModel)(Code) | | Is specified object model supported by this XPathFactory?
Parameters:
objectModel - Specifies the object model which the returned XPathFactory will understand. true if XPathFactory supports objectModel, else false.
throws:
NullPointerException - If objectModel is null.
throws:
IllegalArgumentException - If objectModel.length() == 0. |
| newInstance | | final public static XPathFactory newInstance()(Code) | | Get a new XPathFactory instance using the default object model,
XPathFactory.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.
Instance of an XPathFactory.
throws:
RuntimeException - When there is a failure in creating anXPathFactory for the default object model. |
| newInstance | | final public static XPathFactory newInstance(String uri) throws XPathFactoryConfigurationException(Code) | | 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
XPathFactory.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:
XPathFactory.isObjectModelSupported(String objectModel)
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.
XPathFactory.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 XPathFactory.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. Instance of an XPathFactory.
throws:
XPathFactoryConfigurationException - If the specified object model is unavailable.
throws:
NullPointerException - If uri is null.
throws:
IllegalArgumentException - If uri is nullor uri.length() == 0. |
| newInstance | | public static XPathFactory newInstance(String uri, String factoryClassName, ClassLoader classLoader) throws XPathFactoryConfigurationException(Code) | | 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
to System.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 URI XPathFactory.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.
Parameters:
factoryClassName - fully qualified factory class name that provides implementation of javax.xml.xpath.XPathFactory.
Parameters:
classLoader - ClassLoader used to load the factory class. If null current Thread's context classLoader is used to load the factory class. New instance of a XPathFactory
throws:
XPathFactoryConfigurationException - if factoryClassName is null, or the factory class cannot be loaded, instantiated or the factory class does not support the object model specified in the uri parameter.
throws:
NullPointerException - If uri is null.
throws:
IllegalArgumentException - If uri is nullor uri.length() == 0.
See Also: XPathFactory.newInstance()
See Also: XPathFactory.newInstance(String uri)
since:
1.6 |
| newXPath | | abstract public XPath newXPath()(Code) | | Return a new XPath using the underlying object
model determined when the XPathFactory was instantiated.
New instance of an XPath. |
| setXPathFunctionResolver | | abstract public void setXPathFunctionResolver(XPathFunctionResolver resolver)(Code) | | 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 isnull. |
| setXPathVariableResolver | | abstract public void setXPathVariableResolver(XPathVariableResolver resolver)(Code) | | 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 isnull. |
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