| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| /* |
| * $Id: ObjectFactory.java 468653 2006-10-28 07:07:05Z minchau $ |
| */ |
| |
| package org.apache.xml.dtm; |
| |
| import java.io.InputStream; |
| import java.io.IOException; |
| import java.io.File; |
| import java.io.FileInputStream; |
| |
| import java.util.Properties; |
| import java.io.BufferedReader; |
| import java.io.InputStreamReader; |
| |
| /** |
| * This class is duplicated for each JAXP subpackage so keep it in sync. |
| * It is package private and therefore is not exposed as part of the JAXP |
| * API. |
| * <p> |
| * This code is designed to implement the JAXP 1.1 spec pluggability |
| * feature and is designed to run on JDK version 1.1 and |
| * later, and to compile on JDK 1.2 and onward. |
| * The code also runs both as part of an unbundled jar file and |
| * when bundled as part of the JDK. |
| * <p> |
| * This class was moved from the <code>javax.xml.parsers.ObjectFactory</code> |
| * class and modified to be used as a general utility for creating objects |
| * dynamically. |
| * |
| * @version $Id: ObjectFactory.java 468653 2006-10-28 07:07:05Z minchau $ |
| */ |
| class ObjectFactory { |
| |
| // |
| // Constants |
| // |
| |
| // name of default properties file to look for in JDK's jre/lib directory |
| private static final String DEFAULT_PROPERTIES_FILENAME = |
| "xalan.properties"; |
| |
| private static final String SERVICES_PATH = "META-INF/services/"; |
| |
| /** Set to true for debugging */ |
| private static final boolean DEBUG = false; |
| |
| /** cache the contents of the xalan.properties file. |
| * Until an attempt has been made to read this file, this will |
| * be null; if the file does not exist or we encounter some other error |
| * during the read, this will be empty. |
| */ |
| private static Properties fXalanProperties = null; |
| |
| /*** |
| * Cache the time stamp of the xalan.properties file so |
| * that we know if it's been modified and can invalidate |
| * the cache when necessary. |
| */ |
| private static long fLastModified = -1; |
| |
| // |
| // Public static methods |
| // |
| |
| /** |
| * Finds the implementation Class object in the specified order. The |
| * specified order is the following: |
| * <ol> |
| * <li>query the system property using <code>System.getProperty</code> |
| * <li>read <code>META-INF/services/<i>factoryId</i></code> file |
| * <li>use fallback classname |
| * </ol> |
| * |
| * @return instance of factory, never null |
| * |
| * @param factoryId Name of the factory to find, same as |
| * a property name |
| * @param fallbackClassName Implementation class name, if nothing else |
| * is found. Use null to mean no fallback. |
| * |
| * @exception ObjectFactory.ConfigurationError |
| */ |
| static Object createObject(String factoryId, String fallbackClassName) |
| throws ConfigurationError { |
| return createObject(factoryId, null, fallbackClassName); |
| } // createObject(String,String):Object |
| |
| /** |
| * Finds the implementation Class object in the specified order. The |
| * specified order is the following: |
| * <ol> |
| * <li>query the system property using <code>System.getProperty</code> |
| * <li>read <code>$java.home/lib/<i>propertiesFilename</i></code> file |
| * <li>read <code>META-INF/services/<i>factoryId</i></code> file |
| * <li>use fallback classname |
| * </ol> |
| * |
| * @return instance of factory, never null |
| * |
| * @param factoryId Name of the factory to find, same as |
| * a property name |
| * @param propertiesFilename The filename in the $java.home/lib directory |
| * of the properties file. If none specified, |
| * ${java.home}/lib/xalan.properties will be used. |
| * @param fallbackClassName Implementation class name, if nothing else |
| * is found. Use null to mean no fallback. |
| * |
| * @exception ObjectFactory.ConfigurationError |
| */ |
| static Object createObject(String factoryId, |
| String propertiesFilename, |
| String fallbackClassName) |
| throws ConfigurationError |
| { |
| Class factoryClass = lookUpFactoryClass(factoryId, |
| propertiesFilename, |
| fallbackClassName); |
| |
| if (factoryClass == null) { |
| throw new ConfigurationError( |
| "Provider for " + factoryId + " cannot be found", null); |
| } |
| |
| try{ |
| Object instance = factoryClass.newInstance(); |
| debugPrintln("created new instance of factory " + factoryId); |
| return instance; |
| } catch (Exception x) { |
| throw new ConfigurationError( |
| "Provider for factory " + factoryId |
| + " could not be instantiated: " + x, x); |
| } |
| } // createObject(String,String,String):Object |
| |
| /** |
| * Finds the implementation Class object in the specified order. The |
| * specified order is the following: |
| * <ol> |
| * <li>query the system property using <code>System.getProperty</code> |
| * <li>read <code>$java.home/lib/<i>propertiesFilename</i></code> file |
| * <li>read <code>META-INF/services/<i>factoryId</i></code> file |
| * <li>use fallback classname |
| * </ol> |
| * |
| * @return Class object of factory, never null |
| * |
| * @param factoryId Name of the factory to find, same as |
| * a property name |
| * @param propertiesFilename The filename in the $java.home/lib directory |
| * of the properties file. If none specified, |
| * ${java.home}/lib/xalan.properties will be used. |
| * @param fallbackClassName Implementation class name, if nothing else |
| * is found. Use null to mean no fallback. |
| * |
| * @exception ObjectFactory.ConfigurationError |
| */ |
| static Class lookUpFactoryClass(String factoryId) |
| throws ConfigurationError |
| { |
| return lookUpFactoryClass(factoryId, null, null); |
| } // lookUpFactoryClass(String):Class |
| |
| /** |
| * Finds the implementation Class object in the specified order. The |
| * specified order is the following: |
| * <ol> |
| * <li>query the system property using <code>System.getProperty</code> |
| * <li>read <code>$java.home/lib/<i>propertiesFilename</i></code> file |
| * <li>read <code>META-INF/services/<i>factoryId</i></code> file |
| * <li>use fallback classname |
| * </ol> |
| * |
| * @return Class object that provides factory service, never null |
| * |
| * @param factoryId Name of the factory to find, same as |
| * a property name |
| * @param propertiesFilename The filename in the $java.home/lib directory |
| * of the properties file. If none specified, |
| * ${java.home}/lib/xalan.properties will be used. |
| * @param fallbackClassName Implementation class name, if nothing else |
| * is found. Use null to mean no fallback. |
| * |
| * @exception ObjectFactory.ConfigurationError |
| */ |
| static Class lookUpFactoryClass(String factoryId, |
| String propertiesFilename, |
| String fallbackClassName) |
| throws ConfigurationError |
| { |
| String factoryClassName = lookUpFactoryClassName(factoryId, |
| propertiesFilename, |
| fallbackClassName); |
| ClassLoader cl = findClassLoader(); |
| |
| if (factoryClassName == null) { |
| factoryClassName = fallbackClassName; |
| } |
| |
| // assert(className != null); |
| try{ |
| Class providerClass = findProviderClass(factoryClassName, |
| cl, |
| true); |
| debugPrintln("created new instance of " + providerClass + |
| " using ClassLoader: " + cl); |
| return providerClass; |
| } catch (ClassNotFoundException x) { |
| throw new ConfigurationError( |
| "Provider " + factoryClassName + " not found", x); |
| } catch (Exception x) { |
| throw new ConfigurationError( |
| "Provider "+factoryClassName+" could not be instantiated: "+x, |
| x); |
| } |
| } // lookUpFactoryClass(String,String,String):Class |
| |
| /** |
| * Finds the name of the required implementation class in the specified |
| * order. The specified order is the following: |
| * <ol> |
| * <li>query the system property using <code>System.getProperty</code> |
| * <li>read <code>$java.home/lib/<i>propertiesFilename</i></code> file |
| * <li>read <code>META-INF/services/<i>factoryId</i></code> file |
| * <li>use fallback classname |
| * </ol> |
| * |
| * @return name of class that provides factory service, never null |
| * |
| * @param factoryId Name of the factory to find, same as |
| * a property name |
| * @param propertiesFilename The filename in the $java.home/lib directory |
| * of the properties file. If none specified, |
| * ${java.home}/lib/xalan.properties will be used. |
| * @param fallbackClassName Implementation class name, if nothing else |
| * is found. Use null to mean no fallback. |
| * |
| * @exception ObjectFactory.ConfigurationError |
| */ |
| static String lookUpFactoryClassName(String factoryId, |
| String propertiesFilename, |
| String fallbackClassName) |
| { |
| SecuritySupport ss = SecuritySupport.getInstance(); |
| |
| // Use the system property first |
| try { |
| String systemProp = ss.getSystemProperty(factoryId); |
| if (systemProp != null) { |
| debugPrintln("found system property, value=" + systemProp); |
| return systemProp; |
| } |
| } catch (SecurityException se) { |
| // Ignore and continue w/ next location |
| } |
| |
| // Try to read from propertiesFilename, or |
| // $java.home/lib/xalan.properties |
| String factoryClassName = null; |
| // no properties file name specified; use |
| // $JAVA_HOME/lib/xalan.properties: |
| if (propertiesFilename == null) { |
| File propertiesFile = null; |
| boolean propertiesFileExists = false; |
| try { |
| String javah = ss.getSystemProperty("java.home"); |
| propertiesFilename = javah + File.separator + |
| "lib" + File.separator + DEFAULT_PROPERTIES_FILENAME; |
| propertiesFile = new File(propertiesFilename); |
| propertiesFileExists = ss.getFileExists(propertiesFile); |
| } catch (SecurityException e) { |
| // try again... |
| fLastModified = -1; |
| fXalanProperties = null; |
| } |
| |
| synchronized (ObjectFactory.class) { |
| boolean loadProperties = false; |
| FileInputStream fis = null; |
| try { |
| // file existed last time |
| if(fLastModified >= 0) { |
| if(propertiesFileExists && |
| (fLastModified < (fLastModified = ss.getLastModified(propertiesFile)))) { |
| loadProperties = true; |
| } else { |
| // file has stopped existing... |
| if(!propertiesFileExists) { |
| fLastModified = -1; |
| fXalanProperties = null; |
| } // else, file wasn't modified! |
| } |
| } else { |
| // file has started to exist: |
| if(propertiesFileExists) { |
| loadProperties = true; |
| fLastModified = ss.getLastModified(propertiesFile); |
| } // else, nothing's changed |
| } |
| if(loadProperties) { |
| // must never have attempted to read xalan.properties |
| // before (or it's outdeated) |
| fXalanProperties = new Properties(); |
| fis = ss.getFileInputStream(propertiesFile); |
| fXalanProperties.load(fis); |
| } |
| } catch (Exception x) { |
| fXalanProperties = null; |
| fLastModified = -1; |
| // assert(x instanceof FileNotFoundException |
| // || x instanceof SecurityException) |
| // In both cases, ignore and continue w/ next location |
| } |
| finally { |
| // try to close the input stream if one was opened. |
| if (fis != null) { |
| try { |
| fis.close(); |
| } |
| // Ignore the exception. |
| catch (IOException exc) {} |
| } |
| } |
| } |
| if(fXalanProperties != null) { |
| factoryClassName = fXalanProperties.getProperty(factoryId); |
| } |
| } else { |
| FileInputStream fis = null; |
| try { |
| fis = ss.getFileInputStream(new File(propertiesFilename)); |
| Properties props = new Properties(); |
| props.load(fis); |
| factoryClassName = props.getProperty(factoryId); |
| } catch (Exception x) { |
| // assert(x instanceof FileNotFoundException |
| // || x instanceof SecurityException) |
| // In both cases, ignore and continue w/ next location |
| } |
| finally { |
| // try to close the input stream if one was opened. |
| if (fis != null) { |
| try { |
| fis.close(); |
| } |
| // Ignore the exception. |
| catch (IOException exc) {} |
| } |
| } |
| } |
| if (factoryClassName != null) { |
| debugPrintln("found in " + propertiesFilename + ", value=" |
| + factoryClassName); |
| return factoryClassName; |
| } |
| |
| // Try Jar Service Provider Mechanism |
| return findJarServiceProviderName(factoryId); |
| } // lookUpFactoryClass(String,String):String |
| |
| // |
| // Private static methods |
| // |
| |
| /** Prints a message to standard error if debugging is enabled. */ |
| private static void debugPrintln(String msg) { |
| if (DEBUG) { |
| System.err.println("JAXP: " + msg); |
| } |
| } // debugPrintln(String) |
| |
| /** |
| * Figure out which ClassLoader to use. For JDK 1.2 and later use |
| * the context ClassLoader. |
| */ |
| static ClassLoader findClassLoader() |
| throws ConfigurationError |
| { |
| SecuritySupport ss = SecuritySupport.getInstance(); |
| |
| // Figure out which ClassLoader to use for loading the provider |
| // class. If there is a Context ClassLoader then use it. |
| ClassLoader context = ss.getContextClassLoader(); |
| ClassLoader system = ss.getSystemClassLoader(); |
| |
| ClassLoader chain = system; |
| while (true) { |
| if (context == chain) { |
| // Assert: we are on JDK 1.1 or we have no Context ClassLoader |
| // or any Context ClassLoader in chain of system classloader |
| // (including extension ClassLoader) so extend to widest |
| // ClassLoader (always look in system ClassLoader if Xalan |
| // is in boot/extension/system classpath and in current |
| // ClassLoader otherwise); normal classloaders delegate |
| // back to system ClassLoader first so this widening doesn't |
| // change the fact that context ClassLoader will be consulted |
| ClassLoader current = ObjectFactory.class.getClassLoader(); |
| |
| chain = system; |
| while (true) { |
| if (current == chain) { |
| // Assert: Current ClassLoader in chain of |
| // boot/extension/system ClassLoaders |
| return system; |
| } |
| if (chain == null) { |
| break; |
| } |
| chain = ss.getParentClassLoader(chain); |
| } |
| |
| // Assert: Current ClassLoader not in chain of |
| // boot/extension/system ClassLoaders |
| return current; |
| } |
| |
| if (chain == null) { |
| // boot ClassLoader reached |
| break; |
| } |
| |
| // Check for any extension ClassLoaders in chain up to |
| // boot ClassLoader |
| chain = ss.getParentClassLoader(chain); |
| }; |
| |
| // Assert: Context ClassLoader not in chain of |
| // boot/extension/system ClassLoaders |
| return context; |
| } // findClassLoader():ClassLoader |
| |
| /** |
| * Create an instance of a class using the specified ClassLoader |
| */ |
| static Object newInstance(String className, ClassLoader cl, |
| boolean doFallback) |
| throws ConfigurationError |
| { |
| // assert(className != null); |
| try{ |
| Class providerClass = findProviderClass(className, cl, doFallback); |
| Object instance = providerClass.newInstance(); |
| debugPrintln("created new instance of " + providerClass + |
| " using ClassLoader: " + cl); |
| return instance; |
| } catch (ClassNotFoundException x) { |
| throw new ConfigurationError( |
| "Provider " + className + " not found", x); |
| } catch (Exception x) { |
| throw new ConfigurationError( |
| "Provider " + className + " could not be instantiated: " + x, |
| x); |
| } |
| } |
| |
| /** |
| * Find a Class using the specified ClassLoader |
| */ |
| static Class findProviderClass(String className, ClassLoader cl, |
| boolean doFallback) |
| throws ClassNotFoundException, ConfigurationError |
| { |
| //throw security exception if the calling thread is not allowed to access the |
| //class. Restrict the access to the package classes as specified in java.security policy. |
| SecurityManager security = System.getSecurityManager(); |
| try{ |
| if (security != null){ |
| final int lastDot = className.lastIndexOf("."); |
| String packageName = className; |
| if (lastDot != -1) packageName = className.substring(0, lastDot); |
| security.checkPackageAccess(packageName); |
| } |
| }catch(SecurityException e){ |
| throw e; |
| } |
| |
| Class providerClass; |
| if (cl == null) { |
| // XXX Use the bootstrap ClassLoader. There is no way to |
| // load a class using the bootstrap ClassLoader that works |
| // in both JDK 1.1 and Java 2. However, this should still |
| // work b/c the following should be true: |
| // |
| // (cl == null) iff current ClassLoader == null |
| // |
| // Thus Class.forName(String) will use the current |
| // ClassLoader which will be the bootstrap ClassLoader. |
| providerClass = Class.forName(className); |
| } else { |
| try { |
| providerClass = cl.loadClass(className); |
| } catch (ClassNotFoundException x) { |
| if (doFallback) { |
| // Fall back to current classloader |
| ClassLoader current = ObjectFactory.class.getClassLoader(); |
| if (current == null) { |
| providerClass = Class.forName(className); |
| } else if (cl != current) { |
| cl = current; |
| providerClass = cl.loadClass(className); |
| } else { |
| throw x; |
| } |
| } else { |
| throw x; |
| } |
| } |
| } |
| |
| return providerClass; |
| } |
| |
| /** |
| * Find the name of service provider using Jar Service Provider Mechanism |
| * |
| * @return instance of provider class if found or null |
| */ |
| private static String findJarServiceProviderName(String factoryId) |
| { |
| SecuritySupport ss = SecuritySupport.getInstance(); |
| String serviceId = SERVICES_PATH + factoryId; |
| InputStream is = null; |
| |
| // First try the Context ClassLoader |
| ClassLoader cl = findClassLoader(); |
| |
| is = ss.getResourceAsStream(cl, serviceId); |
| |
| // If no provider found then try the current ClassLoader |
| if (is == null) { |
| ClassLoader current = ObjectFactory.class.getClassLoader(); |
| if (cl != current) { |
| cl = current; |
| is = ss.getResourceAsStream(cl, serviceId); |
| } |
| } |
| |
| if (is == null) { |
| // No provider found |
| return null; |
| } |
| |
| debugPrintln("found jar resource=" + serviceId + |
| " using ClassLoader: " + cl); |
| |
| // Read the service provider name in UTF-8 as specified in |
| // the jar spec. Unfortunately this fails in Microsoft |
| // VJ++, which does not implement the UTF-8 |
| // encoding. Theoretically, we should simply let it fail in |
| // that case, since the JVM is obviously broken if it |
| // doesn't support such a basic standard. But since there |
| // are still some users attempting to use VJ++ for |
| // development, we have dropped in a fallback which makes a |
| // second attempt using the platform's default encoding. In |
| // VJ++ this is apparently ASCII, which is a subset of |
| // UTF-8... and since the strings we'll be reading here are |
| // also primarily limited to the 7-bit ASCII range (at |
| // least, in English versions), this should work well |
| // enough to keep us on the air until we're ready to |
| // officially decommit from VJ++. [Edited comment from |
| // jkesselm] |
| BufferedReader rd; |
| try { |
| rd = new BufferedReader(new InputStreamReader(is, "UTF-8")); |
| } catch (java.io.UnsupportedEncodingException e) { |
| rd = new BufferedReader(new InputStreamReader(is)); |
| } |
| |
| String factoryClassName = null; |
| try { |
| // XXX Does not handle all possible input as specified by the |
| // Jar Service Provider specification |
| factoryClassName = rd.readLine(); |
| } catch (IOException x) { |
| // No provider found |
| return null; |
| } |
| finally { |
| try { |
| // try to close the reader. |
| rd.close(); |
| } |
| // Ignore the exception. |
| catch (IOException exc) {} |
| } |
| |
| if (factoryClassName != null && |
| ! "".equals(factoryClassName)) { |
| debugPrintln("found in resource, value=" |
| + factoryClassName); |
| |
| // Note: here we do not want to fall back to the current |
| // ClassLoader because we want to avoid the case where the |
| // resource file was found using one ClassLoader and the |
| // provider class was instantiated using a different one. |
| return factoryClassName; |
| } |
| |
| // No provider found |
| return null; |
| } |
| |
| // |
| // Classes |
| // |
| |
| /** |
| * A configuration error. |
| */ |
| static class ConfigurationError |
| extends Error { |
| static final long serialVersionUID = 5122054096615067992L; |
| // |
| // Data |
| // |
| |
| /** Exception. */ |
| private Exception exception; |
| |
| // |
| // Constructors |
| // |
| |
| /** |
| * Construct a new instance with the specified detail string and |
| * exception. |
| */ |
| ConfigurationError(String msg, Exception x) { |
| super(msg); |
| this.exception = x; |
| } // <init>(String,Exception) |
| |
| // |
| // Public methods |
| // |
| |
| /** Returns the exception associated to this error. */ |
| Exception getException() { |
| return exception; |
| } // getException():Exception |
| |
| } // class ConfigurationError |
| |
| } // class ObjectFactory |