java.lang.Object javax.xml.xpath.XPathFactory
public abstract class XPathFactory
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.
Field Summary | |
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static String |
DEFAULT_OBJECT_MODEL_URI
Default Object Model URI. |
static String |
DEFAULT_PROPERTY_NAME
The default property name according to the JAXP spec. |
Constructor Summary | |
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protected |
XPathFactory
() Protected constructor as newInstance() or newInstance(String uri) or newInstance(String uri, String factoryClassName, ClassLoader classLoader) should be used to create a new instance of an XPathFactory. |
Method Summary | |
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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 XPathFactory |
newInstance
() Get a new XPathFactory instance using the default object model, DEFAULT_OBJECT_MODEL_URI , the W3C DOM. |
static XPathFactory |
newInstance
(
String
uri) Get a new XPathFactory instance using the specified object model. |
static XPathFactory |
newInstance
(
String
uri,
String
factoryClassName,
ClassLoader
classLoader) Obtain a new instance of a XPathFactory from a factory class name. |
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 XPaths created by this factory. |
abstract void |
setXPathFunctionResolver
(
XPathFunctionResolver
resolver) Establish a default function resolver. |
abstract void |
setXPathVariableResolver
(
XPathVariableResolver
resolver) Establish a default variable resolver. |
Methods inherited from class java.lang. Object |
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clone , equals , finalize , getClass , hashCode , notify , notifyAll , toString , wait , wait , wait |
Field Detail |
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public static final String DEFAULT_PROPERTY_NAME
The default property name according to the JAXP spec.
public static final String DEFAULT_OBJECT_MODEL_URI
Default Object Model URI.
Constructor Detail |
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protected XPathFactory()
Protected constructor as newInstance() or newInstance(String uri) or newInstance(String uri, String factoryClassName, ClassLoader classLoader) should be used to create a new instance of an XPathFactory.
Method Detail |
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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.
public static final XPathFactory newInstance(String uri) throws XPathFactoryConfigurationException
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:
isObjectModelSupported(String objectModel)The first service provider found in class loader order that supports the specified object model is returned.
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
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.
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 ....
public abstract boolean isObjectModelSupported(String objectModel)
Is specified object model supported by this XPathFactory?
public abstract void setFeature(String name, boolean value) throws XPathFactoryConfigurationException
Set a feature for this XPathFactory and XPaths created by this factory.
Feature names are fully qualified 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.
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 .
public abstract boolean getFeature(String name) throws XPathFactoryConfigurationException
Get the state of the named feature.
Feature names are fully qualified 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.
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.
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.
public abstract XPath newXPath()
Return a new XPath using the underlying object model determined when the XPathFactory was instantiated.