Java tutorial
/* * Copyright (c) 2000, 2017, 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.transform; import com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl; /** * <p>A TransformerFactory instance can be used to create * {@link javax.xml.transform.Transformer} and * {@link javax.xml.transform.Templates} objects. * * <p>The system property that determines which Factory implementation * to create is named {@code "javax.xml.transform.TransformerFactory"}. * This property names a concrete subclass of the * {@code TransformerFactory} abstract class. If the property is not * defined, a platform default is be used. * * @author Jeff Suttor * @author Neeraj Bajaj * * @since 1.5 */ public abstract class TransformerFactory { /** * Default constructor is protected on purpose. */ protected TransformerFactory() { } /** * Creates a new instance of the {@code TransformerFactory} builtin * system-default implementation. * * @return A new instance of the {@code TransformerFactory} builtin * system-default implementation. * * @since 9 */ public static TransformerFactory newDefaultInstance() { return new TransformerFactoryImpl(); } /** * Obtain a new instance of a {@code TransformerFactory}. * This static method creates a new factory instance. * <p> * This method uses the following ordered lookup procedure to determine * the {@code TransformerFactory} implementation class to load: * <ul> * <li> * Use the {@code javax.xml.transform.TransformerFactory} system * property. * </li> * <li> * <p> * Use the configuration file "jaxp.properties". The file is in standard * {@link java.util.Properties} format and typically located in the * {@code conf} directory of the Java installation. It contains the fully qualified * name of the implementation class with the key being the system property * defined above. * <p> * The jaxp.properties file is read only once by the JAXP implementation * and its values are then cached for future use. If the file does not exist * when the first attempt is made to read from it, no further attempts are * made to check for its existence. It is not possible to change the value * of any property in jaxp.properties after it has been read for the first time. * </li> * <li> * <p> * Use the service-provider loading facility, 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. * </li> * <li> * <p> * Otherwise, the {@linkplain #newDefaultInstance() system-default} * implementation is returned. * </li> * </ul> * * <p> * Once an application has obtained a reference to a * {@code TransformerFactory} it can use the factory to configure * and obtain transformer instances. * * @return new TransformerFactory instance, never null. * * @throws TransformerFactoryConfigurationError Thrown in case of {@linkplain * java.util.ServiceConfigurationError service configuration error} or if * the implementation is not available or cannot be instantiated. */ public static TransformerFactory newInstance() throws TransformerFactoryConfigurationError { return FactoryFinder.find( /* The default property name according to the JAXP spec */ TransformerFactory.class, /* The fallback implementation class name, XSLTC */ "com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl"); } /** * Obtain a new instance of a {@code TransformerFactory} from factory class name. * 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>Once an application has obtained a reference to a * {@code TransformerFactory} it can use the factory to configure * and obtain transformer instances. * * <h4>Tip for Trouble-shooting</h4> * <p>Setting the {@code jaxp.debug} system property will cause * this method to print a lot of debug messages * to {@code System.err} about what it is doing and where it is looking at. * * <p> If you have problems try: * <pre> * java -Djaxp.debug=1 YourProgram .... * </pre> * * @param factoryClassName fully qualified factory class name that provides implementation of {@code javax.xml.transform.TransformerFactory}. * * @param classLoader {@code ClassLoader} used to load the factory class. If {@code null} * current {@code Thread}'s context classLoader is used to load the factory class. * * @return new TransformerFactory instance, never null. * * @throws TransformerFactoryConfigurationError * if {@code factoryClassName} is {@code null}, or * the factory class cannot be loaded, instantiated. * * @see #newInstance() * * @since 1.6 */ public static TransformerFactory newInstance(String factoryClassName, ClassLoader classLoader) throws TransformerFactoryConfigurationError { //do not fallback if given classloader can't find the class, throw exception return FactoryFinder.newInstance(TransformerFactory.class, factoryClassName, classLoader, false); } /** * Process the {@code Source} into a {@code Transformer} * {@code Object}. The {@code Source} is an XSLT document that * conforms to <a href="http://www.w3.org/TR/xslt"> * XSL Transformations (XSLT) Version 1.0</a>. Care must * be taken not to use this {@code Transformer} in multiple * {@code Thread}s running concurrently. * Different {@code TransformerFactories} can be used concurrently by * different {@code Thread}s. * * @param source {@code Source } of XSLT document used to create * {@code Transformer}. * Examples of XML {@code Source}s include * {@link javax.xml.transform.dom.DOMSource DOMSource}, * {@link javax.xml.transform.sax.SAXSource SAXSource}, and * {@link javax.xml.transform.stream.StreamSource StreamSource}. * * @return A {@code Transformer} object that may be used to perform * a transformation in a single {@code Thread}, never * {@code null}. * * @throws TransformerConfigurationException Thrown if there are errors when * parsing the {@code Source} or it is not possible to create a * {@code Transformer} instance. * * @see <a href="http://www.w3.org/TR/xslt"> * XSL Transformations (XSLT) Version 1.0</a> */ public abstract Transformer newTransformer(Source source) throws TransformerConfigurationException; /** * Create a new {@code Transformer} that performs a copy * of the {@code Source} to the {@code Result}. * i.e. the "<em>identity transform</em>". * * @return A Transformer object that may be used to perform a transformation * in a single thread, never null. * * @throws TransformerConfigurationException When it is not * possible to create a {@code Transformer} instance. */ public abstract Transformer newTransformer() throws TransformerConfigurationException; /** * Process the Source into a Templates object, which is a * a compiled representation of the source. This Templates object * may then be used concurrently across multiple threads. Creating * a Templates object allows the TransformerFactory to do detailed * performance optimization of transformation instructions, without * penalizing runtime transformation. * * @param source An object that holds a URL, input stream, etc. * * @return A Templates object capable of being used for transformation * purposes, never {@code null}. * * @throws TransformerConfigurationException When parsing to * construct the Templates object fails. */ public abstract Templates newTemplates(Source source) throws TransformerConfigurationException; /** * Get the stylesheet specification(s) associated with the * XML {@code Source} document via the * <a href="http://www.w3.org/TR/xml-stylesheet/"> * xml-stylesheet processing instruction</a> that match the given criteria. * Note that it is possible to return several stylesheets, in which case * they are applied as if they were a list of imports or cascades in a * single stylesheet. * * @param source The XML source document. * @param media The media attribute to be matched. May be null, in which * case the prefered templates will be used (i.e. alternate = no). * @param title The value of the title attribute to match. May be null. * @param charset The value of the charset attribute to match. May be null. * * @return A {@code Source} {@code Object} suitable for passing * to the {@code TransformerFactory}. * * @throws TransformerConfigurationException An {@code Exception} * is thrown if an error occurings during parsing of the * {@code source}. * * @see <a href="http://www.w3.org/TR/xml-stylesheet/"> * Associating Style Sheets with XML documents Version 1.0</a> */ public abstract Source getAssociatedStylesheet(Source source, String media, String title, String charset) throws TransformerConfigurationException; /** * Set an object that is used by default during the transformation * to resolve URIs used in document(), xsl:import, or xsl:include. * * @param resolver An object that implements the URIResolver interface, * or null. */ public abstract void setURIResolver(URIResolver resolver); /** * Get the object that is used by default during the transformation * to resolve URIs used in document(), xsl:import, or xsl:include. * * @return The URIResolver that was set with setURIResolver. */ public abstract URIResolver getURIResolver(); //======= CONFIGURATION METHODS ======= /** * <p>Set a feature for this {@code TransformerFactory} and {@code Transformer}s * or {@code Template}s created by this factory. * * <p> * Feature names are fully qualified {@link java.net.URI}s. * Implementations may define their own features. * An {@link TransformerConfigurationException} is thrown if this {@code TransformerFactory} or the * {@code Transformer}s or {@code Template}s it creates cannot support the feature. * It is possible for an {@code TransformerFactory} to expose a feature value but be unable to change its state. * * <p>All implementations are required to support the {@link javax.xml.XMLConstants#FEATURE_SECURE_PROCESSING} feature. * When the feature is: * <ul> * <li> * {@code true}: the implementation will limit XML processing to conform to implementation limits * and behave in a secure fashion as defined by the implementation. * Examples include resolving user defined style sheets and functions. * If XML processing is limited for security reasons, it will be reported via a call to the registered * {@link ErrorListener#fatalError(TransformerException exception)}. * See {@link #setErrorListener(ErrorListener listener)}. * </li> * <li> * {@code false}: the implementation will processing XML according to the XML specifications without * regard to possible implementation limits. * </li> * </ul> * * @param name Feature name. * @param value Is feature state {@code true} or {@code false}. * * @throws TransformerConfigurationException if this {@code TransformerFactory} * or the {@code Transformer}s or {@code Template}s it creates cannot support this feature. * @throws NullPointerException If the {@code name} parameter is null. */ public abstract void setFeature(String name, boolean value) throws TransformerConfigurationException; /** * Look up the value of a feature. * * <p> * Feature names are fully qualified {@link java.net.URI}s. * Implementations may define their own features. * {@code false} is returned if this {@code TransformerFactory} or the * {@code Transformer}s or {@code Template}s it creates cannot support the feature. * It is possible for an {@code TransformerFactory} to expose a feature value but be unable to change its state. * * @param name Feature name. * * @return The current state of the feature, {@code true} or {@code false}. * * @throws NullPointerException If the {@code name} parameter is null. */ public abstract boolean getFeature(String name); /** * Allows the user to set specific attributes on the underlying * implementation. An attribute in this context is defined to * be an option that the implementation provides. * An {@code IllegalArgumentException} is thrown if the underlying * implementation doesn't recognize the attribute. * <p> * All implementations that implement JAXP 1.5 or newer are required to * support the {@link javax.xml.XMLConstants#ACCESS_EXTERNAL_DTD} and * {@link javax.xml.XMLConstants#ACCESS_EXTERNAL_STYLESHEET} properties. * * <ul> * <li> * <p> * Access to external DTDs in the source file is restricted to the protocols * specified by the {@link javax.xml.XMLConstants#ACCESS_EXTERNAL_DTD} property. * If access is denied during transformation due to the restriction of this property, * {@link javax.xml.transform.TransformerException} will be thrown by * {@link javax.xml.transform.Transformer#transform(Source, Result)}. * * <p> * Access to external DTDs in the stylesheet is restricted to the protocols * specified by the {@link javax.xml.XMLConstants#ACCESS_EXTERNAL_DTD} property. * If access is denied during the creation of a new transformer due to the * restriction of this property, * {@link javax.xml.transform.TransformerConfigurationException} will be thrown * by the {@link #newTransformer(Source)} method. * * <p> * Access to external reference set by the stylesheet processing instruction, * Import and Include element is restricted to the protocols specified by the * {@link javax.xml.XMLConstants#ACCESS_EXTERNAL_STYLESHEET} property. * If access is denied during the creation of a new transformer due to the * restriction of this property, * {@link javax.xml.transform.TransformerConfigurationException} will be thrown * by the {@link #newTransformer(Source)} method. * * <p> * Access to external document through XSLT document function is restricted * to the protocols specified by the property. If access is denied during * the transformation due to the restriction of this property, * {@link javax.xml.transform.TransformerException} will be thrown by the * {@link javax.xml.transform.Transformer#transform(Source, Result)} method. * * </li> * </ul> * * @param name The name of the attribute. * @param value The value of the attribute. * * @throws IllegalArgumentException When implementation does not * recognize the attribute. */ public abstract void setAttribute(String name, Object value); /** * Allows the user to retrieve specific attributes on the underlying * implementation. * An {@code IllegalArgumentException} is thrown if the underlying * implementation doesn't recognize the attribute. * * @param name The name of the attribute. * * @return value The value of the attribute. * * @throws IllegalArgumentException When implementation does not * recognize the attribute. */ public abstract Object getAttribute(String name); /** * Set the error event listener for the TransformerFactory, which * is used for the processing of transformation instructions, * and not for the transformation itself. * An {@code IllegalArgumentException} is thrown if the * {@code ErrorListener} listener is {@code null}. * * @param listener The new error listener. * * @throws IllegalArgumentException When {@code listener} is * {@code null} */ public abstract void setErrorListener(ErrorListener listener); /** * Get the error event handler for the TransformerFactory. * * @return The current error handler, which should never be null. */ public abstract ErrorListener getErrorListener(); }