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/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* published by the Free Software Foundation. Oracle designates this
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*
* This code is distributed in the hope that it will be useful, but WITHOUT
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package javax.xml.xpath;
import com.sun.org.apache.xpath.internal.jaxp.XPathFactoryImpl;
import jdk.xml.internal.SecuritySupport;
/**
* An {@code XPathFactory} instance can be used to create
* {@link javax.xml.xpath.XPath} objects.
*
*See {@link #newInstance(String uri)} for lookup mechanism.
*
* The {@link 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 {@link XPathFactory} object at any
* given moment. Implementations are encouraged to mark methods
* as synchronized to protect themselves from broken clients.
*
*
{@link 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
*
* @since 1.5
*/
public abstract class XPathFactory {
/**
*
The default property name according to the JAXP spec.
*/
public static final String DEFAULT_PROPERTY_NAME = "javax.xml.xpath.XPathFactory";
/**
* Default Object Model URI.
*/
public static final String DEFAULT_OBJECT_MODEL_URI = "http://java.sun.com/jaxp/xpath/dom";
/**
* Protected constructor as {@link #newInstance()} or {@link #newInstance(String uri)}
* or {@link #newInstance(String uri, String factoryClassName, ClassLoader classLoader)}
* should be used to create a new instance of an {@code XPathFactory}.
*/
protected XPathFactory() {
}
/**
* Creates a new instance of the {@code XPathFactory} builtin
* system-default implementation.
*
* @implSpec The {@code XPathFactory} builtin
* system-default implementation is only required to support the
* {@link #DEFAULT_OBJECT_MODEL_URI default object model}, the
* {@linkplain org.w3c.dom W3C DOM}, but may support additional
* object models.
*
* @return A new instance of the {@code XPathFactory} builtin
* system-default implementation.
*
* @since 9
*/
public static XPathFactory newDefaultInstance() {
return new XPathFactoryImpl();
}
/**
* Get a new {@code XPathFactory} instance using the default object model,
* {@link #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.
*
* @return Instance of an {@code XPathFactory}.
*
* @throws RuntimeException When there is a failure in creating an
* {@code XPathFactory} for the default object model.
*/
public static XPathFactory newInstance() {
try {
return newInstance(DEFAULT_OBJECT_MODEL_URI);
} catch (XPathFactoryConfigurationException e) {
throw new RuntimeException(
"XPathFactory#newInstance() failed to create an XPathFactory for the default object model: "
+ DEFAULT_OBJECT_MODEL_URI
+ " with the XPathFactoryConfigurationException: "
+ e.getMessage(), e
);
}
}
/**
* Obtains a new {@code XPathFactory} instance using the specified object model.
* This method uses the
* JAXP Lookup Mechanism
* to determine and load the {@code XPathFactory} implementation that supports
* the specified object model.
*
* Tip for Trouble-shooting:
*
See {@link 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
*
*
* @param uri Identifies the underlying object model.
* The specification only defines the URI {@link #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.
*
* @return Instance of an {@code XPathFactory}.
*
* @throws XPathFactoryConfigurationException If the specified object model
* is unavailable, or if there is a configuration error.
* @throws NullPointerException If uri is null.
* @throws IllegalArgumentException If uri is null
* or uri.length() == 0.
*/
public static XPathFactory newInstance(final String uri)
throws XPathFactoryConfigurationException {
if (uri == null) {
throw new NullPointerException(
"XPathFactory#newInstance(String uri) cannot be called with uri == null");
}
if (uri.length() == 0) {
throw new IllegalArgumentException(
"XPathFactory#newInstance(String uri) cannot be called with uri == \"\"");
}
ClassLoader classLoader = SecuritySupport.getContextClassLoader();
if (classLoader == null) {
//use the current class loader
classLoader = XPathFactory.class.getClassLoader();
}
XPathFactory xpathFactory = new XPathFactoryFinder(classLoader).newFactory(uri);
if (xpathFactory == null) {
throw new XPathFactoryConfigurationException(
"No XPathFactory implementation found for the object model: "
+ uri);
}
return xpathFactory;
}
/**
* Obtain a new instance of a {@code XPathFactory} from a factory class name. {@code 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 ....
*
*
* @param uri Identifies the underlying object model. The specification only defines the URI
* {@link #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.
*
* @param factoryClassName fully qualified factory class name that provides implementation of javax.xml.xpath.XPathFactory.
*
* @param classLoader ClassLoader used to load the factory class. If null
* current Thread's context classLoader is used to load the factory class.
*
*
* @return New instance of a {@code 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 null
* or uri.length() == 0.
*
* @see #newInstance()
* @see #newInstance(String uri)
*
* @since 1.6
*/
public static XPathFactory newInstance(String uri, String factoryClassName, ClassLoader classLoader)
throws XPathFactoryConfigurationException{
ClassLoader cl = classLoader;
if (uri == null) {
throw new NullPointerException(
"XPathFactory#newInstance(String uri) cannot be called with uri == null");
}
if (uri.length() == 0) {
throw new IllegalArgumentException(
"XPathFactory#newInstance(String uri) cannot be called with uri == \"\"");
}
if (cl == null) {
cl = SecuritySupport.getContextClassLoader();
}
XPathFactory f = new XPathFactoryFinder(cl).createInstance(factoryClassName);
if (f == null) {
throw new XPathFactoryConfigurationException(
"No XPathFactory implementation found for the object model: "
+ uri);
}
//if this factory supports the given schemalanguage return this factory else thrown exception
if (f.isObjectModelSupported(uri)) {
return f;
} else {
throw new XPathFactoryConfigurationException("Factory "
+ factoryClassName + " doesn't support given " + uri
+ " object model");
}
}
/**
* Is specified object model supported by this {@code XPathFactory}?
*
* @param objectModel Specifies the object model which the returned {@code XPathFactory} will understand.
*
* @return true if {@code XPathFactory} supports objectModel, else false.
*
* @throws NullPointerException If objectModel is null.
* @throws IllegalArgumentException If objectModel.length() == 0.
*/
public abstract boolean isObjectModelSupported(String objectModel);
/**
* Set a feature for this {@code XPathFactory} and
* XPaths created by this factory.
*
*
* Feature names are fully qualified {@link java.net.URI}s.
* Implementations may define their own features.
* An {@link XPathFactoryConfigurationException} is thrown if this
* {@code XPathFactory} or the XPaths
* it creates cannot support the feature.
* It is possible for an {@code XPathFactory} to expose a feature value
* but be unable to change its state.
*
*
*
* All implementations are required to support the {@link javax.xml.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 {@link XPathFunctionResolver}
* and must throw an {@link XPathFunctionException}.
*
*
* @param name Feature name.
* @param value Is feature state true or false.
*
* @throws XPathFactoryConfigurationException if this {@code XPathFactory} or the XPaths
* it creates cannot support this feature.
* @throws NullPointerException if name is null.
*/
public abstract void setFeature(String name, boolean value)
throws XPathFactoryConfigurationException;
/**
* Get the state of the named feature.
*
*
* Feature names are fully qualified {@link java.net.URI}s.
* Implementations may define their own features.
* An {@link XPathFactoryConfigurationException} is thrown if this
* {@code XPathFactory} or the XPaths
* it creates cannot support the feature.
* It is possible for an {@code XPathFactory} to expose a feature value
* but be unable to change its state.
*
*
* @param name Feature name.
*
* @return State of the named feature.
*
* @throws XPathFactoryConfigurationException if this
* {@code XPathFactory} or the XPaths
* it creates cannot support this feature.
* @throws NullPointerException if name is null.
*/
public abstract boolean getFeature(String name)
throws XPathFactoryConfigurationException;
/**
* 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.
*
* @param resolver Variable resolver.
*
* @throws NullPointerException If resolver is
* null.
*/
public abstract void setXPathVariableResolver(XPathVariableResolver 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.
*
* @param resolver XPath function resolver.
*
* @throws NullPointerException If resolver is
* null.
*/
public abstract void setXPathFunctionResolver(XPathFunctionResolver resolver);
/**
* Return a new XPath using the underlying object
* model determined when the {@code XPathFactory} was instantiated.
*
* @return New instance of an XPath.
*/
public abstract XPath newXPath();
}