| /* |
| * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * 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). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package javax.xml.xpath; |
| |
| /** |
| * <p>An <code>XPathFactory</code> instance can be used to create |
| * {@link javax.xml.xpath.XPath} objects.</p> |
| * |
| *<p>See {@link #newInstance(String uri)} for lookup mechanism.</p> |
| * |
| * <p>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 <code>synchronized</code> to protect themselves from broken clients. |
| * |
| * <p>{@link XPathFactory} is not re-entrant. While one of the |
| * <code>newInstance</code> methods is being invoked, applications |
| * may not attempt to recursively invoke a <code>newInstance</code> method, |
| * even from the same thread. |
| * |
| * @author <a href="mailto:Norman.Walsh@Sun.com">Norman Walsh</a> |
| * @author <a href="mailto:Jeff.Suttor@Sun.com">Jeff Suttor</a> |
| * |
| * @since 1.5 |
| */ |
| public abstract class XPathFactory { |
| |
| |
| /** |
| * <p>The default property name according to the JAXP spec.</p> |
| */ |
| public static final String DEFAULT_PROPERTY_NAME = "javax.xml.xpath.XPathFactory"; |
| |
| /** |
| * <p>Default Object Model URI.</p> |
| */ |
| public static final String DEFAULT_OBJECT_MODEL_URI = "http://java.sun.com/jaxp/xpath/dom"; |
| |
| /** |
| *<p> Take care of restrictions imposed by java security model </p> |
| */ |
| private static SecuritySupport ss = new SecuritySupport() ; |
| |
| /** |
| * <p>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</code>.</p> |
| */ |
| protected XPathFactory() { |
| } |
| |
| /** |
| * <p>Get a new <code>XPathFactory</code> instance using the default object model, |
| * {@link #DEFAULT_OBJECT_MODEL_URI}, |
| * the W3C DOM.</p> |
| * |
| * <p>This method is functionally equivalent to:</p> |
| * <pre> |
| * newInstance(DEFAULT_OBJECT_MODEL_URI) |
| * </pre> |
| * |
| * <p>Since the implementation for the W3C DOM is always available, this method will never fail.</p> |
| * |
| * @return Instance of an <code>XPathFactory</code>. |
| * |
| * @throws RuntimeException When there is a failure in creating an |
| * <code>XPathFactory</code> for the default object model. |
| */ |
| public static XPathFactory newInstance() { |
| |
| try { |
| return newInstance(DEFAULT_OBJECT_MODEL_URI); |
| } catch (XPathFactoryConfigurationException xpathFactoryConfigurationException) { |
| throw new RuntimeException( |
| "XPathFactory#newInstance() failed to create an XPathFactory for the default object model: " |
| + DEFAULT_OBJECT_MODEL_URI |
| + " with the XPathFactoryConfigurationException: " |
| + xpathFactoryConfigurationException.toString() |
| ); |
| } |
| } |
| |
| /** |
| * <p>Get a new <code>XPathFactory</code> instance using the specified object model.</p> |
| * |
| * <p>To find a <code>XPathFactory</code> object, |
| * this method looks the following places in the following order where "the class loader" refers to the context class loader:</p> |
| * <ol> |
| * <li> |
| * If the system property {@link #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. |
| * </li> |
| * <li> |
| * ${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. |
| * </li> |
| * <li> |
| * Use the service-provider loading facilities, defined by the |
| * {@link java.util.ServiceLoader} class, to attempt to locate and load an |
| * implementation of the service using the {@linkplain |
| * java.util.ServiceLoader#load(java.lang.Class) default loading mechanism}: |
| * the service-provider loading facility will use the {@linkplain |
| * java.lang.Thread#getContextClassLoader() current thread's context class loader} |
| * to attempt to load the service. If the context class |
| * loader is null, the {@linkplain |
| * ClassLoader#getSystemClassLoader() system class loader} will be used. |
| * <br> |
| * Each potential service provider is required to implement the method |
| * {@link #isObjectModelSupported(String objectModel)}. |
| * The first service provider found that supports the specified object |
| * model is returned. |
| * <br> |
| * In case of {@link java.util.ServiceConfigurationError} an |
| * {@link XPathFactoryConfigurationException} will be thrown. |
| * </li> |
| * <li> |
| * Platform default <code>XPathFactory</code> is located in a platform specific way. |
| * There must be a platform default XPathFactory for the W3C DOM, i.e. {@link #DEFAULT_OBJECT_MODEL_URI}. |
| * </li> |
| * </ol> |
| * <p>If everything fails, an <code>XPathFactoryConfigurationException</code> will be thrown.</p> |
| * |
| * <p>Tip for Trouble-shooting:</p> |
| * <p>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:</p> |
| * <pre> |
| * http\://java.sun.com/jaxp/xpath/dom=org.acme.DomXPathFactory |
| * </pre> |
| * |
| * @param uri Identifies the underlying object model. |
| * The specification only defines the URI {@link #DEFAULT_OBJECT_MODEL_URI}, |
| * <code>http://java.sun.com/jaxp/xpath/dom</code> 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</code>. |
| * |
| * @throws XPathFactoryConfigurationException If the specified object model |
| * is unavailable, or if there is a configuration error. |
| * @throws NullPointerException If <code>uri</code> is <code>null</code>. |
| * @throws IllegalArgumentException If <code>uri</code> is <code>null</code> |
| * or <code>uri.length() == 0</code>. |
| */ |
| 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 = ss.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; |
| } |
| |
| /** |
| * <p>Obtain a new instance of a <code>XPathFactory</code> from a factory class name. <code>XPathFactory</code> |
| * 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.</p> |
| * |
| * |
| * <h2>Tip for Trouble-shooting</h2> |
| * <p>Setting the <code>jaxp.debug</code> system property will cause |
| * this method to print a lot of debug messages |
| * to <code>System.err</code> about what it is doing and where it is looking at.</p> |
| * |
| * <p> If you have problems try:</p> |
| * <pre> |
| * java -Djaxp.debug=1 YourProgram .... |
| * </pre> |
| * |
| * @param uri Identifies the underlying object model. The specification only defines the URI |
| * {@link #DEFAULT_OBJECT_MODEL_URI},<code>http://java.sun.com/jaxp/xpath/dom</code> |
| * 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 <code>javax.xml.xpath.XPathFactory</code>. |
| * |
| * @param classLoader <code>ClassLoader</code> used to load the factory class. If <code>null</code> |
| * current <code>Thread</code>'s context classLoader is used to load the factory class. |
| * |
| * |
| * @return New instance of a <code>XPathFactory</code> |
| * |
| * @throws XPathFactoryConfigurationException |
| * if <code>factoryClassName</code> is <code>null</code>, or |
| * the factory class cannot be loaded, instantiated |
| * or the factory class does not support the object model specified |
| * in the <code>uri</code> parameter. |
| * |
| * @throws NullPointerException If <code>uri</code> is <code>null</code>. |
| * @throws IllegalArgumentException If <code>uri</code> is <code>null</code> |
| * or <code>uri.length() == 0</code>. |
| * |
| * @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 = ss.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"); |
| } |
| |
| } |
| |
| /** |
| * <p>Is specified object model supported by this <code>XPathFactory</code>?</p> |
| * |
| * @param objectModel Specifies the object model which the returned <code>XPathFactory</code> will understand. |
| * |
| * @return <code>true</code> if <code>XPathFactory</code> supports <code>objectModel</code>, else <code>false</code>. |
| * |
| * @throws NullPointerException If <code>objectModel</code> is <code>null</code>. |
| * @throws IllegalArgumentException If <code>objectModel.length() == 0</code>. |
| */ |
| public abstract boolean isObjectModelSupported(String objectModel); |
| |
| /** |
| * <p>Set a feature for this <code>XPathFactory</code> and |
| * <code>XPath</code>s created by this factory.</p> |
| * |
| * <p> |
| * 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</code> or the <code>XPath</code>s |
| * it creates cannot support the feature. |
| * It is possible for an <code>XPathFactory</code> to expose a feature value |
| * but be unable to change its state. |
| * </p> |
| * |
| * <p> |
| * All implementations are required to support the {@link javax.xml.XMLConstants#FEATURE_SECURE_PROCESSING} feature. |
| * When the feature is <code>true</code>, 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}. |
| * </p> |
| * |
| * @param name Feature name. |
| * @param value Is feature state <code>true</code> or <code>false</code>. |
| * |
| * @throws XPathFactoryConfigurationException if this <code>XPathFactory</code> or the <code>XPath</code>s |
| * it creates cannot support this feature. |
| * @throws NullPointerException if <code>name</code> is <code>null</code>. |
| */ |
| public abstract void setFeature(String name, boolean value) |
| throws XPathFactoryConfigurationException; |
| |
| /** |
| * <p>Get the state of the named feature.</p> |
| * |
| * <p> |
| * 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</code> or the <code>XPath</code>s |
| * it creates cannot support the feature. |
| * It is possible for an <code>XPathFactory</code> to expose a feature value |
| * but be unable to change its state. |
| * </p> |
| * |
| * @param name Feature name. |
| * |
| * @return State of the named feature. |
| * |
| * @throws XPathFactoryConfigurationException if this |
| * <code>XPathFactory</code> or the <code>XPath</code>s |
| * it creates cannot support this feature. |
| * @throws NullPointerException if <code>name</code> is <code>null</code>. |
| */ |
| public abstract boolean getFeature(String name) |
| throws XPathFactoryConfigurationException; |
| |
| /** |
| * <p>Establish a default variable resolver.</p> |
| * |
| * <p>Any <code>XPath</code> objects constructed from this factory will use |
| * the specified resolver by default.</p> |
| * |
| * <p>A <code>NullPointerException</code> is thrown if <code>resolver</code> |
| * is <code>null</code>.</p> |
| * |
| * @param resolver Variable resolver. |
| * |
| * @throws NullPointerException If <code>resolver</code> is |
| * <code>null</code>. |
| */ |
| public abstract void setXPathVariableResolver(XPathVariableResolver resolver); |
| |
| /** |
| * <p>Establish a default function resolver.</p> |
| * |
| * <p>Any <code>XPath</code> objects constructed from this factory will |
| * use the specified resolver by default.</p> |
| * |
| * <p>A <code>NullPointerException</code> is thrown if |
| * <code>resolver</code> is <code>null</code>.</p> |
| * |
| * @param resolver XPath function resolver. |
| * |
| * @throws NullPointerException If <code>resolver</code> is |
| * <code>null</code>. |
| */ |
| public abstract void setXPathFunctionResolver(XPathFunctionResolver resolver); |
| |
| /** |
| * <p>Return a new <code>XPath</code> using the underlying object |
| * model determined when the <code>XPathFactory</code> was instantiated.</p> |
| * |
| * @return New instance of an <code>XPath</code>. |
| */ |
| public abstract XPath newXPath(); |
| } |
