--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/com/sun/naming/internal/ResourceManager.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,561 @@
+/*
+ * Copyright 1999-2001 Sun Microsystems, Inc. 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package com.sun.naming.internal;
+
+import java.applet.Applet;
+import java.io.InputStream;
+import java.io.IOException;
+import java.net.URL;
+import java.lang.ref.WeakReference;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.Hashtable;
+import java.util.Map;
+import java.util.Properties;
+import java.util.StringTokenizer;
+import java.util.List;
+import java.util.ArrayList;
+import java.util.WeakHashMap;
+
+import javax.naming.*;
+
+/**
+ * The ResourceManager class facilitates the reading of JNDI resource files.
+ *
+ * @author Rosanna Lee
+ * @author Scott Seligman
+ */
+
+public final class ResourceManager {
+
+ /*
+ * Name of provider resource files (without the package-name prefix.)
+ */
+ private static final String PROVIDER_RESOURCE_FILE_NAME =
+ "jndiprovider.properties";
+
+ /*
+ * Name of application resource files.
+ */
+ private static final String APP_RESOURCE_FILE_NAME = "jndi.properties";
+
+ /*
+ * Name of properties file in <java.home>/lib.
+ */
+ private static final String JRELIB_PROPERTY_FILE_NAME = "jndi.properties";
+
+ /*
+ * The standard JNDI properties that specify colon-separated lists.
+ */
+ private static final String[] listProperties = {
+ Context.OBJECT_FACTORIES,
+ Context.URL_PKG_PREFIXES,
+ Context.STATE_FACTORIES,
+ // The following shouldn't create a runtime dependence on ldap package.
+ javax.naming.ldap.LdapContext.CONTROL_FACTORIES
+ };
+
+ private static final VersionHelper helper =
+ VersionHelper.getVersionHelper();
+
+ /*
+ * A cache of the properties that have been constructed by
+ * the ResourceManager. A Hashtable from a provider resource
+ * file is keyed on a class in the resource file's package.
+ * One from application resource files is keyed on the thread's
+ * context class loader.
+ */
+ private static final WeakHashMap propertiesCache = new WeakHashMap(11);
+
+ /*
+ * A cache of factory objects (ObjectFactory, StateFactory, ControlFactory).
+ *
+ * A two-level cache keyed first on context class loader and then
+ * on propValue. Value is a list of class or factory objects,
+ * weakly referenced so as not to prevent GC of the class loader.
+ * Used in getFactories().
+ */
+ private static final WeakHashMap factoryCache = new WeakHashMap(11);
+
+ /*
+ * A cache of URL factory objects (ObjectFactory).
+ *
+ * A two-level cache keyed first on context class loader and then
+ * on classSuffix+propValue. Value is the factory itself (weakly
+ * referenced so as not to prevent GC of the class loader) or
+ * NO_FACTORY if a previous search revealed no factory. Used in
+ * getFactory().
+ */
+ private static final WeakHashMap urlFactoryCache = new WeakHashMap(11);
+ private static final WeakReference NO_FACTORY = new WeakReference(null);
+
+
+ // There should be no instances of this class.
+ private ResourceManager() {
+ }
+
+
+ // ---------- Public methods ----------
+
+ /*
+ * Given the environment parameter passed to the initial context
+ * constructor, returns the full environment for that initial
+ * context (never null). This is based on the environment
+ * parameter, the applet parameters (where appropriate), the
+ * system properties, and all application resource files.
+ *
+ * <p> This method will modify <tt>env</tt> and save
+ * a reference to it. The caller may no longer modify it.
+ *
+ * @param env environment passed to initial context constructor.
+ * Null indicates an empty environment.
+ *
+ * @throws NamingException if an error occurs while reading a
+ * resource file
+ */
+ public static Hashtable getInitialEnvironment(Hashtable env)
+ throws NamingException
+ {
+ String[] props = VersionHelper.PROPS; // system/applet properties
+ if (env == null) {
+ env = new Hashtable(11);
+ }
+ Applet applet = (Applet)env.get(Context.APPLET);
+
+ // Merge property values from env param, applet params, and system
+ // properties. The first value wins: there's no concatenation of
+ // colon-separated lists.
+ // Read system properties by first trying System.getProperties(),
+ // and then trying System.getProperty() if that fails. The former
+ // is more efficient due to fewer permission checks.
+ //
+ String[] jndiSysProps = helper.getJndiProperties();
+ for (int i = 0; i < props.length; i++) {
+ Object val = env.get(props[i]);
+ if (val == null) {
+ if (applet != null) {
+ val = applet.getParameter(props[i]);
+ }
+ if (val == null) {
+ // Read system property.
+ val = (jndiSysProps != null)
+ ? jndiSysProps[i]
+ : helper.getJndiProperty(i);
+ }
+ if (val != null) {
+ env.put(props[i], val);
+ }
+ }
+ }
+
+ // Merge the above with the values read from all application
+ // resource files. Colon-separated lists are concatenated.
+ mergeTables(env, getApplicationResources());
+ return env;
+ }
+
+ /**
+ * Retrieves the property from the environment, or from the provider
+ * resource file associated with the given context. The environment
+ * may in turn contain values that come from applet parameters,
+ * system properties, or application resource files.
+ *
+ * If <tt>concat</tt> is true and both the environment and the provider
+ * resource file contain the property, the two values are concatenated
+ * (with a ':' separator).
+ *
+ * Returns null if no value is found.
+ *
+ * @param propName The non-null property name
+ * @param env The possibly null environment properties
+ * @param ctx The possibly null context
+ * @param concat True if multiple values should be concatenated
+ * @return the property value, or null is there is none.
+ * @throws NamingException if an error occurs while reading the provider
+ * resource file.
+ */
+ public static String getProperty(String propName, Hashtable env,
+ Context ctx, boolean concat)
+ throws NamingException {
+
+ String val1 = (env != null) ? (String)env.get(propName) : null;
+ if ((ctx == null) ||
+ ((val1 != null) && !concat)) {
+ return val1;
+ }
+ String val2 = (String)getProviderResource(ctx).get(propName);
+ if (val1 == null) {
+ return val2;
+ } else if ((val2 == null) || !concat) {
+ return val1;
+ } else {
+ return (val1 + ":" + val2);
+ }
+ }
+
+ /**
+ * Retrieves an enumeration of factory classes/object specified by a
+ * property.
+ *
+ * The property is gotten from the environment and the provider
+ * resource file associated with the given context and concantenated.
+ * See getProperty(). The resulting property value is a list of class names.
+ *<p>
+ * This method then loads each class using the current thread's context
+ * class loader and keeps them in a list. Any class that cannot be loaded
+ * is ignored. The resulting list is then cached in a two-level
+ * hash table, keyed first by the context class loader and then by
+ * the property's value.
+ * The next time threads of the same context class loader call this
+ * method, they can use the cached list.
+ *<p>
+ * After obtaining the list either from the cache or by creating one from
+ * the property value, this method then creates and returns a
+ * FactoryEnumeration using the list. As the FactoryEnumeration is
+ * traversed, the cached Class object in the list is instantiated and
+ * replaced by an instance of the factory object itself. Both class
+ * objects and factories are wrapped in weak references so as not to
+ * prevent GC of the class loader.
+ *<p>
+ * Note that multiple threads can be accessing the same cached list
+ * via FactoryEnumeration, which locks the list during each next().
+ * The size of the list will not change,
+ * but a cached Class object might be replaced by an instantiated factory
+ * object.
+ *
+ * @param propName The non-null property name
+ * @param env The possibly null environment properties
+ * @param ctx The possibly null context
+ * @return An enumeration of factory classes/objects; null if none.
+ * @exception NamingException If encounter problem while reading the provider
+ * property file.
+ * @see javax.naming.spi.NamingManager#getObjectInstance
+ * @see javax.naming.spi.NamingManager#getStateToBind
+ * @see javax.naming.spi.DirectoryManager#getObjectInstance
+ * @see javax.naming.spi.DirectoryManager#getStateToBind
+ * @see javax.naming.ldap.ControlFactory#getControlInstance
+ */
+ public static FactoryEnumeration getFactories(String propName, Hashtable env,
+ Context ctx) throws NamingException {
+
+ String facProp = getProperty(propName, env, ctx, true);
+ if (facProp == null)
+ return null; // no classes specified; return null
+
+ // Cache is based on context class loader and property val
+ ClassLoader loader = helper.getContextClassLoader();
+
+ Map perLoaderCache = null;
+ synchronized (factoryCache) {
+ perLoaderCache = (Map) factoryCache.get(loader);
+ if (perLoaderCache == null) {
+ perLoaderCache = new HashMap(11);
+ factoryCache.put(loader, perLoaderCache);
+ }
+ }
+
+ synchronized (perLoaderCache) {
+ List factories = (List) perLoaderCache.get(facProp);
+ if (factories != null) {
+ // Cached list
+ return factories.size() == 0 ? null
+ : new FactoryEnumeration(factories, loader);
+ } else {
+ // Populate list with classes named in facProp; skipping
+ // those that we cannot load
+ StringTokenizer parser = new StringTokenizer(facProp, ":");
+ factories = new ArrayList(5);
+ while (parser.hasMoreTokens()) {
+ try {
+ // System.out.println("loading");
+ String className = parser.nextToken();
+ Class c = helper.loadClass(className, loader);
+ factories.add(new NamedWeakReference(c, className));
+ } catch (Exception e) {
+ // ignore ClassNotFoundException, IllegalArgumentException
+ }
+ }
+ // System.out.println("adding to cache: " + factories);
+ perLoaderCache.put(facProp, factories);
+ return new FactoryEnumeration(factories, loader);
+ }
+ }
+ }
+
+ /**
+ * Retrieves a factory from a list of packages specified in a
+ * property.
+ *
+ * The property is gotten from the environment and the provider
+ * resource file associated with the given context and concatenated.
+ * classSuffix is added to the end of this list.
+ * See getProperty(). The resulting property value is a list of package
+ * prefixes.
+ *<p>
+ * This method then constructs a list of class names by concatenating
+ * each package prefix with classSuffix and attempts to load and
+ * instantiate the class until one succeeds.
+ * Any class that cannot be loaded is ignored.
+ * The resulting object is then cached in a two-level hash table,
+ * keyed first by the context class loader and then by the property's
+ * value and classSuffix.
+ * The next time threads of the same context class loader call this
+ * method, they use the cached factory.
+ * If no factory can be loaded, NO_FACTORY is recorded in the table
+ * so that next time it'll return quickly.
+ *
+ * @param propName The non-null property name
+ * @param env The possibly null environment properties
+ * @param ctx The possibly null context
+ * @param classSuffix The non-null class name
+ * (e.g. ".ldap.ldapURLContextFactory).
+ * @param defaultPkgPrefix The non-null default package prefix.
+ * (e.g., "com.sun.jndi.url").
+ * @return An factory object; null if none.
+ * @exception NamingException If encounter problem while reading the provider
+ * property file, or problem instantiating the factory.
+ *
+ * @see javax.naming.spi.NamingManager#getURLContext
+ * @see javax.naming.spi.NamingManager#getURLObject
+ */
+ public static Object getFactory(String propName, Hashtable env, Context ctx,
+ String classSuffix, String defaultPkgPrefix) throws NamingException {
+
+ // Merge property with provider property and supplied default
+ String facProp = getProperty(propName, env, ctx, true);
+ if (facProp != null)
+ facProp += (":" + defaultPkgPrefix);
+ else
+ facProp = defaultPkgPrefix;
+
+ // Cache factory based on context class loader, class name, and
+ // property val
+ ClassLoader loader = helper.getContextClassLoader();
+ String key = classSuffix + " " + facProp;
+
+ Map perLoaderCache = null;
+ synchronized (urlFactoryCache) {
+ perLoaderCache = (Map) urlFactoryCache.get(loader);
+ if (perLoaderCache == null) {
+ perLoaderCache = new HashMap(11);
+ urlFactoryCache.put(loader, perLoaderCache);
+ }
+ }
+
+ synchronized (perLoaderCache) {
+ Object factory = null;
+
+ WeakReference factoryRef = (WeakReference) perLoaderCache.get(key);
+ if (factoryRef == NO_FACTORY) {
+ return null;
+ } else if (factoryRef != null) {
+ factory = factoryRef.get();
+ if (factory != null) { // check if weak ref has been cleared
+ return factory;
+ }
+ }
+
+ // Not cached; find first factory and cache
+ StringTokenizer parser = new StringTokenizer(facProp, ":");
+ String className;
+ while (factory == null && parser.hasMoreTokens()) {
+ className = parser.nextToken() + classSuffix;
+ try {
+ // System.out.println("loading " + className);
+ factory = helper.loadClass(className, loader).newInstance();
+ } catch (InstantiationException e) {
+ NamingException ne =
+ new NamingException("Cannot instantiate " + className);
+ ne.setRootCause(e);
+ throw ne;
+ } catch (IllegalAccessException e) {
+ NamingException ne =
+ new NamingException("Cannot access " + className);
+ ne.setRootCause(e);
+ throw ne;
+ } catch (Exception e) {
+ // ignore ClassNotFoundException, IllegalArgumentException,
+ // etc.
+ }
+ }
+
+ // Cache it.
+ perLoaderCache.put(key, (factory != null)
+ ? new WeakReference(factory)
+ : NO_FACTORY);
+ return factory;
+ }
+ }
+
+
+ // ---------- Private methods ----------
+
+ /*
+ * Returns the properties contained in the provider resource file
+ * of an object's package. Returns an empty hash table if the
+ * object is null or the resource file cannot be found. The
+ * results are cached.
+ *
+ * @throws NamingException if an error occurs while reading the file.
+ */
+ private static Hashtable getProviderResource(Object obj)
+ throws NamingException
+ {
+ if (obj == null) {
+ return (new Hashtable(1));
+ }
+ synchronized (propertiesCache) {
+ Class c = obj.getClass();
+
+ Hashtable props = (Hashtable)propertiesCache.get(c);
+ if (props != null) {
+ return props;
+ }
+ props = new Properties();
+
+ InputStream istream =
+ helper.getResourceAsStream(c, PROVIDER_RESOURCE_FILE_NAME);
+
+ if (istream != null) {
+ try {
+ ((Properties)props).load(istream);
+ } catch (IOException e) {
+ NamingException ne = new ConfigurationException(
+ "Error reading provider resource file for " + c);
+ ne.setRootCause(e);
+ throw ne;
+ }
+ }
+ propertiesCache.put(c, props);
+ return props;
+ }
+ }
+
+
+ /*
+ * Returns the Hashtable (never null) that results from merging
+ * all application resource files available to this thread's
+ * context class loader. The properties file in <java.home>/lib
+ * is also merged in. The results are cached.
+ *
+ * SECURITY NOTES:
+ * 1. JNDI needs permission to read the application resource files.
+ * 2. Any class will be able to use JNDI to view the contents of
+ * the application resource files in its own classpath. Give
+ * careful consideration to this before storing sensitive
+ * information there.
+ *
+ * @throws NamingException if an error occurs while reading a resource
+ * file.
+ */
+ private static Hashtable getApplicationResources() throws NamingException {
+
+ ClassLoader cl = helper.getContextClassLoader();
+
+ synchronized (propertiesCache) {
+ Hashtable result = (Hashtable)propertiesCache.get(cl);
+ if (result != null) {
+ return result;
+ }
+
+ try {
+ NamingEnumeration resources =
+ helper.getResources(cl, APP_RESOURCE_FILE_NAME);
+ while (resources.hasMore()) {
+ Properties props = new Properties();
+ props.load((InputStream)resources.next());
+
+ if (result == null) {
+ result = props;
+ } else {
+ mergeTables(result, props);
+ }
+ }
+
+ // Merge in properties from file in <java.home>/lib.
+ InputStream istream =
+ helper.getJavaHomeLibStream(JRELIB_PROPERTY_FILE_NAME);
+ if (istream != null) {
+ Properties props = new Properties();
+ props.load(istream);
+
+ if (result == null) {
+ result = props;
+ } else {
+ mergeTables(result, props);
+ }
+ }
+
+ } catch (IOException e) {
+ NamingException ne = new ConfigurationException(
+ "Error reading application resource file");
+ ne.setRootCause(e);
+ throw ne;
+ }
+ if (result == null) {
+ result = new Hashtable(11);
+ }
+ propertiesCache.put(cl, result);
+ return result;
+ }
+ }
+
+ /*
+ * Merge the properties from one hash table into another. Each
+ * property in props2 that is not in props1 is added to props1.
+ * For each property in both hash tables that is one of the
+ * standard JNDI properties that specify colon-separated lists,
+ * the values are concatenated and stored in props1.
+ */
+ private static void mergeTables(Hashtable props1, Hashtable props2) {
+ Enumeration keys = props2.keys();
+
+ while (keys.hasMoreElements()) {
+ String prop = (String)keys.nextElement();
+ Object val1 = props1.get(prop);
+ if (val1 == null) {
+ props1.put(prop, props2.get(prop));
+ } else if (isListProperty(prop)) {
+ String val2 = (String)props2.get(prop);
+ props1.put(prop, ((String)val1) + ":" + val2);
+ }
+ }
+ }
+
+ /*
+ * Is a property one of the standard JNDI properties that specify
+ * colon-separated lists?
+ */
+ private static boolean isListProperty(String prop) {
+ prop = prop.intern();
+ for (int i = 0; i < listProperties.length; i++) {
+ if (prop == listProperties[i]) {
+ return true;
+ }
+ }
+ return false;
+ }
+}