/* * Copyright (c) 1999, 2004, 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 com.sun.jndi.rmi.registry;  import java.util.Enumeration;import java.util.Hashtable; import javax.naming.*;import javax.naming.spi.*; import com.sun.jndi.url.rmi.rmiURLContextFactory; /** * A RegistryContextFactory takes an RMI registry reference, and * creates the corresponding RMI object or registry context.  In * addition, it serves as the initial context factory when using an * RMI registry as an initial context. *<p> * When an initial context is being created, the environment * property "java.naming.provider.url" should contain the RMI URL of * the appropriate registry.  Otherwise, the default URL "rmi:" is used. *<p> * An RMI registry reference contains one or more StringRefAddrs of * type "URL", each containing a single RMI URL.  Other addresses * are ignored.  Multiple URLs represent alternative addresses for the * same logical resource.  The order of the addresses is not significant. * * @author Scott Seligman */  public class RegistryContextFactory        implements ObjectFactory, InitialContextFactory{    /**     * The type of each address in an RMI registry reference.     */    public final static String ADDRESS_TYPE = "URL";     public Context getInitialContext(Hashtable<?,?> env) throws NamingException {         if (env != null) {            env = (Hashtable) env.clone();        }        return URLToContext(getInitCtxURL(env), env);    }     public Object getObjectInstance(Object ref, Name name, Context nameCtx,                                    Hashtable<?,?> env)            throws NamingException    {        if (!isRegistryRef(ref)) {            return null;        }        /*         * No need to clone env here.  If getObjectInstance()         * returns something other than a RegistryContext (which         * happens if you're looking up an object bound in the         * registry, as opposed to looking up the registry itself),         * then the context is GCed right away and there's no need to         * clone the environment.  If getObjectInstance() returns a         * RegistryContext, then it still goes through         * GenericURLContext, which calls RegistryContext.lookup()         * with an empty name, which clones the environment.         */        Object obj = URLsToObject(getURLs((Reference)ref), env);        if (obj instanceof RegistryContext) {            RegistryContext ctx = (RegistryContext)obj;            ctx.reference = (Reference)ref;        }        return obj;    }     private static Context URLToContext(String url, Hashtable env)            throws NamingException    {        rmiURLContextFactory factory = new rmiURLContextFactory();        Object obj = factory.getObjectInstance(url, null, null, env);         if (obj instanceof Context) {            return (Context)obj;        } else {            throw (new NotContextException(url));        }    }     private static Object URLsToObject(String[] urls, Hashtable env)            throws NamingException    {        rmiURLContextFactory factory = new rmiURLContextFactory();        return factory.getObjectInstance(urls, null, null, env);    }     /**     * Reads environment to find URL of initial context.     * The default URL is "rmi:".     */    private static String getInitCtxURL(Hashtable env) {         final String defaultURL = "rmi:";         String url = null;        if (env != null) {            url = (String)env.get(Context.PROVIDER_URL);        }        return ((url != null) ? url : defaultURL);    }     /**     * Returns true if argument is an RMI registry reference.     */    private static boolean isRegistryRef(Object obj) {         if (!(obj instanceof Reference)) {            return false;        }        String thisClassName = RegistryContextFactory.class.getName();        Reference ref = (Reference)obj;         return thisClassName.equals(ref.getFactoryClassName());    }     /**     * Returns the URLs contained within an RMI registry reference.     */    private static String[] getURLs(Reference ref) throws NamingException {         int size = 0;   // number of URLs        String[] urls = new String[ref.size()];         Enumeration addrs = ref.getAll();        while (addrs.hasMoreElements()) {            RefAddr addr = (RefAddr)addrs.nextElement();             if ((addr instanceof StringRefAddr) &&                addr.getType().equals(ADDRESS_TYPE)) {                 urls[size++] = (String)addr.getContent();            }        }        if (size == 0) {            throw (new ConfigurationException(                    "Reference contains no valid addresses"));        }         // Trim URL array down to size.        if (size == ref.size()) {            return urls;        }        String[] urls2 = new String[size];        System.arraycopy(urls, 0, urls2, 0, size);        return urls2;    }}