| /* |
| * Copyright (c) 2005, 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.stream; |
| |
| import java.io.File; |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| import java.util.Iterator; |
| import java.util.Properties; |
| import java.util.ServiceConfigurationError; |
| import java.util.ServiceLoader; |
| import java.util.function.Supplier; |
| |
| /** |
| * <p>Implements pluggable streams.</p> |
| * |
| * <p>This class is duplicated for each JAXP subpackage so keep it in |
| * sync. It is package private for secure class loading.</p> |
| * |
| * @author Santiago.PericasGeertsen@sun.com |
| */ |
| class FactoryFinder { |
| // Check we have access to package. |
| private static final String DEFAULT_PACKAGE = "com.sun.xml.internal."; |
| |
| /** |
| * Internal debug flag. |
| */ |
| private static boolean debug = false; |
| |
| /** |
| * Cache for properties in java.home/conf/jaxp.properties |
| */ |
| final private static Properties cacheProps = new Properties(); |
| |
| /** |
| * Flag indicating if properties from java.home/conf/jaxp.properties |
| * have been cached. |
| */ |
| private static volatile boolean firstTime = true; |
| |
| /** |
| * Security support class use to check access control before |
| * getting certain system resources. |
| */ |
| final private static SecuritySupport ss = new SecuritySupport(); |
| |
| // Define system property "jaxp.debug" to get output |
| static { |
| // Use try/catch block to support applets, which throws |
| // SecurityException out of this code. |
| try { |
| String val = ss.getSystemProperty("jaxp.debug"); |
| // Allow simply setting the prop to turn on debug |
| debug = val != null && !"false".equals(val); |
| } |
| catch (SecurityException se) { |
| debug = false; |
| } |
| } |
| |
| private static void dPrint(Supplier<String> msgGen) { |
| if (debug) { |
| System.err.println("JAXP: " + msgGen.get()); |
| } |
| } |
| |
| /** |
| * Attempt to load a class using the class loader supplied. If that fails |
| * and fall back is enabled, the current (i.e. bootstrap) class loader is |
| * tried. |
| * |
| * If the class loader supplied is <code>null</code>, first try using the |
| * context class loader followed by the current (i.e. bootstrap) class |
| * loader. |
| * |
| * Use bootstrap classLoader if cl = null and useBSClsLoader is true |
| */ |
| static private Class getProviderClass(String className, ClassLoader cl, |
| boolean doFallback, boolean useBSClsLoader) throws ClassNotFoundException |
| { |
| try { |
| if (cl == null) { |
| if (useBSClsLoader) { |
| return Class.forName(className, false, FactoryFinder.class.getClassLoader()); |
| } else { |
| cl = ss.getContextClassLoader(); |
| if (cl == null) { |
| throw new ClassNotFoundException(); |
| } |
| else { |
| return Class.forName(className, false, cl); |
| } |
| } |
| } |
| else { |
| return Class.forName(className, false, cl); |
| } |
| } |
| catch (ClassNotFoundException e1) { |
| if (doFallback) { |
| // Use current class loader - should always be bootstrap CL |
| return Class.forName(className, false, FactoryFinder.class.getClassLoader()); |
| } |
| else { |
| throw e1; |
| } |
| } |
| } |
| |
| /** |
| * Create an instance of a class. Delegates to method |
| * <code>getProviderClass()</code> in order to load the class. |
| * |
| * @param type Base class / Service interface of the factory to |
| * instantiate. |
| * |
| * @param className Name of the concrete class corresponding to the |
| * service provider |
| * |
| * @param cl <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. |
| * |
| * @param doFallback True if the current ClassLoader should be tried as |
| * a fallback if the class is not found using cl |
| */ |
| static <T> T newInstance(Class<T> type, String className, ClassLoader cl, boolean doFallback) |
| throws FactoryConfigurationError |
| { |
| return newInstance(type, className, cl, doFallback, false); |
| } |
| |
| /** |
| * Create an instance of a class. Delegates to method |
| * <code>getProviderClass()</code> in order to load the class. |
| * |
| * @param type Base class / Service interface of the factory to |
| * instantiate. |
| * |
| * @param className Name of the concrete class corresponding to the |
| * service provider |
| * |
| * @param cl <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. |
| * |
| * @param doFallback True if the current ClassLoader should be tried as |
| * a fallback if the class is not found using cl |
| * |
| * @param useBSClsLoader True if cl=null actually meant bootstrap classLoader. This parameter |
| * is needed since DocumentBuilderFactory/SAXParserFactory defined null as context classLoader. |
| */ |
| static <T> T newInstance(Class<T> type, String className, ClassLoader cl, |
| boolean doFallback, boolean useBSClsLoader) |
| throws FactoryConfigurationError |
| { |
| assert type != null; |
| |
| // make sure we have access to restricted packages |
| if (System.getSecurityManager() != null) { |
| if (className != null && className.startsWith(DEFAULT_PACKAGE)) { |
| cl = null; |
| useBSClsLoader = true; |
| } |
| } |
| |
| try { |
| Class<?> providerClass = getProviderClass(className, cl, doFallback, useBSClsLoader); |
| if (!type.isAssignableFrom(providerClass)) { |
| throw new ClassCastException(className + " cannot be cast to " + type.getName()); |
| } |
| Object instance = providerClass.getConstructor().newInstance(); |
| final ClassLoader clD = cl; |
| dPrint(()->"created new instance of " + providerClass + |
| " using ClassLoader: " + clD); |
| return type.cast(instance); |
| } |
| catch (ClassNotFoundException x) { |
| throw new FactoryConfigurationError( |
| "Provider " + className + " not found", x); |
| } |
| catch (Exception x) { |
| throw new FactoryConfigurationError( |
| "Provider " + className + " could not be instantiated: " + x, |
| x); |
| } |
| } |
| |
| /** |
| * Finds the implementation Class object in the specified order. |
| * |
| * @return Class object of factory, never null |
| * |
| * @param type Base class / Service interface of the |
| * factory to find. |
| * |
| * @param fallbackClassName Implementation class name, if nothing else |
| * is found. Use null to mean no fallback. |
| * |
| * Package private so this code can be shared. |
| */ |
| static <T> T find(Class<T> type, String fallbackClassName) |
| throws FactoryConfigurationError |
| { |
| return find(type, type.getName(), null, fallbackClassName); |
| } |
| |
| /** |
| * Finds the implementation Class object in the specified order. Main |
| * entry point. |
| * @return Class object of factory, never null |
| * |
| * @param type Base class / Service interface of the |
| * factory to find. |
| * |
| * @param factoryId Name of the factory to find, same as |
| * a property name |
| * |
| * @param cl ClassLoader to be used to load the class, null means to use |
| * the bootstrap ClassLoader |
| * |
| * @param fallbackClassName Implementation class name, if nothing else |
| * is found. Use null to mean no fallback. |
| * |
| * Package private so this code can be shared. |
| */ |
| static <T> T find(Class<T> type, String factoryId, ClassLoader cl, String fallbackClassName) |
| throws FactoryConfigurationError |
| { |
| dPrint(()->"find factoryId =" + factoryId); |
| |
| // Use the system property first |
| try { |
| |
| final String systemProp; |
| if (type.getName().equals(factoryId)) { |
| systemProp = ss.getSystemProperty(factoryId); |
| } else { |
| systemProp = System.getProperty(factoryId); |
| } |
| if (systemProp != null) { |
| dPrint(()->"found system property, value=" + systemProp); |
| return newInstance(type, systemProp, cl, true); |
| } |
| } |
| catch (SecurityException se) { |
| throw new FactoryConfigurationError( |
| "Failed to read factoryId '" + factoryId + "'", se); |
| } |
| |
| // Try read $java.home/conf/stax.properties followed by |
| // $java.home/conf/jaxp.properties if former not present |
| String configFile = null; |
| try { |
| if (firstTime) { |
| synchronized (cacheProps) { |
| if (firstTime) { |
| configFile = ss.getSystemProperty("java.home") + File.separator + |
| "conf" + File.separator + "stax.properties"; |
| final File fStax = new File(configFile); |
| firstTime = false; |
| if (ss.doesFileExist(fStax)) { |
| dPrint(()->"Read properties file "+fStax); |
| cacheProps.load(ss.getFileInputStream(fStax)); |
| } |
| else { |
| configFile = ss.getSystemProperty("java.home") + File.separator + |
| "conf" + File.separator + "jaxp.properties"; |
| final File fJaxp = new File(configFile); |
| if (ss.doesFileExist(fJaxp)) { |
| dPrint(()->"Read properties file "+fJaxp); |
| cacheProps.load(ss.getFileInputStream(fJaxp)); |
| } |
| } |
| } |
| } |
| } |
| final String factoryClassName = cacheProps.getProperty(factoryId); |
| |
| if (factoryClassName != null) { |
| final String foundIn = configFile; |
| dPrint(()->"found in " + foundIn + " value=" + factoryClassName); |
| return newInstance(type, factoryClassName, cl, true); |
| } |
| } |
| catch (Exception ex) { |
| if (debug) ex.printStackTrace(); |
| } |
| |
| if (type.getName().equals(factoryId)) { |
| // Try Jar Service Provider Mechanism |
| final T provider = findServiceProvider(type, cl); |
| if (provider != null) { |
| return provider; |
| } |
| } else { |
| // We're in the case where a 'custom' factoryId was provided, |
| // and in every case where that happens, we expect that |
| // fallbackClassName will be null. |
| assert fallbackClassName == null; |
| } |
| if (fallbackClassName == null) { |
| throw new FactoryConfigurationError( |
| "Provider for " + factoryId + " cannot be found", null); |
| } |
| |
| dPrint(()->"loaded from fallback value: " + fallbackClassName); |
| return newInstance(type, fallbackClassName, cl, true); |
| } |
| |
| /* |
| * Try to find provider using the ServiceLoader API |
| * |
| * @param type Base class / Service interface of the factory to find. |
| * |
| * @return instance of provider class if found or null |
| */ |
| private static <T> T findServiceProvider(final Class<T> type, final ClassLoader cl) { |
| try { |
| return AccessController.doPrivileged(new PrivilegedAction<T>() { |
| @Override |
| public T run() { |
| final ServiceLoader<T> serviceLoader; |
| if (cl == null) { |
| //the current thread's context class loader |
| serviceLoader = ServiceLoader.load(type); |
| } else { |
| serviceLoader = ServiceLoader.load(type, cl); |
| } |
| final Iterator<T> iterator = serviceLoader.iterator(); |
| if (iterator.hasNext()) { |
| return iterator.next(); |
| } else { |
| return null; |
| } |
| } |
| }); |
| } catch(ServiceConfigurationError e) { |
| // It is not possible to wrap an error directly in |
| // FactoryConfigurationError - so we need to wrap the |
| // ServiceConfigurationError in a RuntimeException. |
| // The alternative would be to modify the logic in |
| // FactoryConfigurationError to allow setting a |
| // Throwable as the cause, but that could cause |
| // compatibility issues down the road. |
| final RuntimeException x = new RuntimeException( |
| "Provider for " + type + " cannot be created", e); |
| final FactoryConfigurationError error = |
| new FactoryConfigurationError(x, x.getMessage()); |
| throw error; |
| } |
| } |
| |
| } |