/*

 * Copyright (c) 1999, 2014, 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.Hashtable;

import java.util.Properties;

import java.rmi.*;

import java.rmi.server.*;

import java.rmi.registry.Registry;

import java.rmi.registry.LocateRegistry;

import javax.naming.*;

import javax.naming.spi.NamingManager;

/**

 * A RegistryContext is a context representing a remote RMI registry.

 *

 * @author Scott Seligman

 */

public class RegistryContext implements Context, Referenceable {

    private Hashtable<String, Object> environment;

    private Registry registry;

    private String host;

    private int port;

    private static final NameParser nameParser = new AtomicNameParser();

    private static final String SOCKET_FACTORY = "com.sun.jndi.rmi.factory.socket";

    Reference reference = null; // ref used to create this context, if any

    // Environment property that, if set, indicates that a security

    // manager should be installed (if none is already in place).

    public static final String SECURITY_MGR =

            "java.naming.rmi.security.manager";

    /**

     * Returns a context for the registry at a given host and port.

     * If "host" is null, uses default host.

     * If "port" is non-positive, uses default port.

     * Cloning of "env" is handled by caller; see comments within

     * RegistryContextFactory.getObjectInstance(), for example.

     */

    @SuppressWarnings("unchecked")

    public RegistryContext(String host, int port, Hashtable<?, ?> env)

            throws NamingException

    {

        environment = (env == null)

                      ? new Hashtable<String, Object>(5)

                      : (Hashtable<String, Object>) env;

        if (environment.get(SECURITY_MGR) != null) {

            installSecurityMgr();

        }

        // chop off '[' and ']' in an IPv6 literal address

        if ((host != null) && (host.charAt(0) == '[')) {

            host = host.substring(1, host.length() - 1);

        }

        RMIClientSocketFactory socketFactory =

                (RMIClientSocketFactory) environment.get(SOCKET_FACTORY);

        registry = getRegistry(host, port, socketFactory);

        this.host = host;

        this.port = port;

    }

    /**

     * Returns a clone of a registry context.  The context's private state

     * is independent of the original's (so closing one context, for example,

     * won't close the other).

     */

    // %%% Alternatively, this could be done with a clone() method.

    @SuppressWarnings("unchecked") // clone()

    RegistryContext(RegistryContext ctx) {

        environment = (Hashtable<String, Object>)ctx.environment.clone();

        registry = ctx.registry;

        host = ctx.host;

        port = ctx.port;

        reference = ctx.reference;

    }

    protected void finalize() {

        close();

    }

    public Object lookup(Name name) throws NamingException {

        if (name.isEmpty()) {

            return (new RegistryContext(this));

        }

        Remote obj;

        try {

            obj = registry.lookup(name.get(0));

        } catch (NotBoundException e) {

            throw (new NameNotFoundException(name.get(0)));

        } catch (RemoteException e) {

            throw (NamingException)wrapRemoteException(e).fillInStackTrace();

        }

        return (decodeObject(obj, name.getPrefix(1)));

    }

    public Object lookup(String name) throws NamingException {

        return lookup(new CompositeName(name));

    }

    /**

     * If the object to be bound is both Remote and Referenceable, binds the

     * object itself, not its Reference.

     */

    public void bind(Name name, Object obj) throws NamingException {

        if (name.isEmpty()) {

            throw (new InvalidNameException(

                    "RegistryContext: Cannot bind empty name"));

        }

        try {

            registry.bind(name.get(0), encodeObject(obj, name.getPrefix(1)));

        } catch (AlreadyBoundException e) {

            NamingException ne = new NameAlreadyBoundException(name.get(0));

            ne.setRootCause(e);

            throw ne;

        } catch (RemoteException e) {

            throw (NamingException)wrapRemoteException(e).fillInStackTrace();

        }

    }

    public void bind(String name, Object obj) throws NamingException {

        bind(new CompositeName(name), obj);

    }

    public void rebind(Name name, Object obj) throws NamingException {

        if (name.isEmpty()) {

            throw (new InvalidNameException(

                    "RegistryContext: Cannot rebind empty name"));

        }

        try {

            registry.rebind(name.get(0), encodeObject(obj, name.getPrefix(1)));

        } catch (RemoteException e) {

            throw (NamingException)wrapRemoteException(e).fillInStackTrace();

        }

    }

    public void rebind(String name, Object obj) throws NamingException {

        rebind(new CompositeName(name), obj);

    }

    public void unbind(Name name) throws NamingException {

        if (name.isEmpty()) {

            throw (new InvalidNameException(

                    "RegistryContext: Cannot unbind empty name"));

        }

        try {

            registry.unbind(name.get(0));

        } catch (NotBoundException e) {

            // method is idempotent

        } catch (RemoteException e) {

            throw (NamingException)wrapRemoteException(e).fillInStackTrace();

        }

    }

    public void unbind(String name) throws NamingException {

        unbind(new CompositeName(name));

    }

    /**

     * Rename is implemented by this sequence of operations:

     * lookup, bind, unbind.  The sequence is not performed atomically.

     */

    public void rename(Name oldName, Name newName) throws NamingException {

        bind(newName, lookup(oldName));

        unbind(oldName);

    }

    public void rename(String name, String newName) throws NamingException {

        rename(new CompositeName(name), new CompositeName(newName));

    }

    public NamingEnumeration<NameClassPair> list(Name name) throws

            NamingException {

        if (!name.isEmpty()) {

            throw (new InvalidNameException(

                    "RegistryContext: can only list \"\""));

        }

        try {

            String[] names = registry.list();

            return (new NameClassPairEnumeration(names));

        } catch (RemoteException e) {

            throw (NamingException)wrapRemoteException(e).fillInStackTrace();

        }

    }

    public NamingEnumeration<NameClassPair> list(String name) throws

            NamingException {

        return list(new CompositeName(name));

    }

    public NamingEnumeration<Binding> listBindings(Name name)

            throws NamingException

    {

        if (!name.isEmpty()) {

            throw (new InvalidNameException(

                    "RegistryContext: can only list \"\""));

        }

        try {

            String[] names = registry.list();

            return (new BindingEnumeration(this, names));

        } catch (RemoteException e) {

            throw (NamingException)wrapRemoteException(e).fillInStackTrace();

        }

    }

    public NamingEnumeration<Binding> listBindings(String name) throws

            NamingException {

        return listBindings(new CompositeName(name));

    }

    public void destroySubcontext(Name name) throws NamingException {

        throw (new OperationNotSupportedException());

    }

    public void destroySubcontext(String name) throws NamingException {

        throw (new OperationNotSupportedException());

    }

    public Context createSubcontext(Name name) throws NamingException {

        throw (new OperationNotSupportedException());

    }

    public Context createSubcontext(String name) throws NamingException {

        throw (new OperationNotSupportedException());

    }

    public Object lookupLink(Name name) throws NamingException {

        return lookup(name);

    }

    public Object lookupLink(String name) throws NamingException {

        return lookup(name);

    }

    public NameParser getNameParser(Name name) throws NamingException {

        return nameParser;

    }

    public NameParser getNameParser(String name) throws NamingException {

        return nameParser;

    }

    public Name composeName(Name name, Name prefix) throws NamingException {

        Name result = (Name)prefix.clone();

        return result.addAll(name);

    }

    public String composeName(String name, String prefix)

            throws NamingException

    {

        return composeName(new CompositeName(name),

                           new CompositeName(prefix)).toString();

    }

    public Object removeFromEnvironment(String propName)

            throws NamingException

    {

        return environment.remove(propName);

    }

    public Object addToEnvironment(String propName, Object propVal)

            throws NamingException

    {

        if (propName.equals(SECURITY_MGR)) {

            installSecurityMgr();

        }

        return environment.put(propName, propVal);

    }

    @SuppressWarnings("unchecked") // clone()

    public Hashtable<String, Object> getEnvironment() throws NamingException {

        return (Hashtable<String, Object>)environment.clone();

    }

    public void close() {

        environment = null;

        registry = null;

        // &&& If we were caching registry connections, we would probably

        // uncache this one now.

    }

    public String getNameInNamespace() {

        return ""; // Registry has an empty name

    }

    /**

     * Returns an RMI registry reference for this context.

     *<p>

     * If this context was created from a reference, that reference is

     * returned.  Otherwise, an exception is thrown if the registry's

     * host is "localhost" or the default (null).  Although this could

     * possibly make for a valid reference, it's far more likely to be

     * an easily made error.

     *

     * @see RegistryContextFactory

     */

    public Reference getReference() throws NamingException {

        if (reference != null) {

            return (Reference)reference.clone();  // %%% clone the addrs too?

        }

        if (host == null || host.equals("localhost")) {

            throw (new ConfigurationException(

                    "Cannot create a reference for an RMI registry whose " +

                    "host was unspecified or specified as \"localhost\""));

        }

        String url = "rmi://";

        // Enclose IPv6 literal address in '[' and ']'

        url = (host.indexOf(':') > -1) ? url + "[" + host + "]" :

                                         url + host;

        if (port > 0) {

            url += ":" + Integer.toString(port);

        }

        RefAddr addr = new StringRefAddr(RegistryContextFactory.ADDRESS_TYPE,

                                         url);

        return (new Reference(RegistryContext.class.getName(),

                              addr,

                              RegistryContextFactory.class.getName(),

                              null));

    }

    /**

     * Wrap a RemoteException inside a NamingException.

     */

    public static NamingException wrapRemoteException(RemoteException re) {

        NamingException ne;

        if (re instanceof ConnectException) {

            ne = new ServiceUnavailableException();

        } else if (re instanceof AccessException) {

            ne = new NoPermissionException();

        } else if (re instanceof StubNotFoundException ||

            ne = new ConfigurationException();

        } else if (re instanceof ExportException ||

                   re instanceof ConnectIOException ||

                   re instanceof MarshalException ||

                   re instanceof UnmarshalException ||

                   re instanceof NoSuchObjectException) {

            ne = new CommunicationException();

        } else if (re instanceof ServerException &&

                   re.detail instanceof RemoteException) {

            ne = wrapRemoteException((RemoteException)re.detail);

        } else {

            ne = new NamingException();

        }

        ne.setRootCause(re);

        return ne;

    }

    /**

     * Returns the registry at a given host, port and socket factory.

     * If "host" is null, uses default host.

     * If "port" is non-positive, uses default port.

     * If "socketFactory" is null, uses the default socket.

     */

    private static Registry getRegistry(String host, int port,

                RMIClientSocketFactory socketFactory)

            throws NamingException

    {

        // %%% We could cache registry connections here.  The transport layer

        // may already reuse connections.

        try {

            if (socketFactory == null) {

                return LocateRegistry.getRegistry(host, port);

            } else {

                return LocateRegistry.getRegistry(host, port, socketFactory);

            }

        } catch (RemoteException e) {

            throw (NamingException)wrapRemoteException(e).fillInStackTrace();

        }

    }

    /**

     * Attempts to install a security manager if none is currently in

     * place.

     */

    private static void installSecurityMgr() {

        try {

        } catch (Exception e) {

        }

    }

    /**

     * Encodes an object prior to binding it in the registry.  First,

     * NamingManager.getStateToBind() is invoked.  If the resulting

     * object is Remote, it is returned.  If it is a Reference or

     * Referenceable, the reference is wrapped in a Remote object.

     * Otherwise, an exception is thrown.

     *

     * @param name      The object's name relative to this context.

     */

    private Remote encodeObject(Object obj, Name name)

            throws NamingException, RemoteException

    {

        obj = NamingManager.getStateToBind(obj, name, this, environment);

        if (obj instanceof Remote) {

            return (Remote)obj;

        }

        if (obj instanceof Reference) {

            return (new ReferenceWrapper((Reference)obj));

        }

        if (obj instanceof Referenceable) {

            return (new ReferenceWrapper(((Referenceable)obj).getReference()));

        }

        throw (new IllegalArgumentException(

                "RegistryContext: " +

                "object to bind must be Remote, Reference, or Referenceable"));

    }

    /**

     * Decodes an object that has been retrieved from the registry.

     * First, if the object is a RemoteReference, the Reference is

     * unwrapped.  Then, NamingManager.getObjectInstance() is invoked.

     *

     * @param name      The object's name relative to this context.

     */

    private Object decodeObject(Remote r, Name name) throws NamingException {

        try {

            Object obj = (r instanceof RemoteReference)

                        ? ((RemoteReference)r).getReference()

                        : (Object)r;

            return NamingManager.getObjectInstance(obj, name, this,

                                                   environment);

        } catch (NamingException e) {

            throw e;

        } catch (RemoteException e) {

            throw (NamingException)

                wrapRemoteException(e).fillInStackTrace();

        } catch (Exception e) {

            NamingException ne = new NamingException();

            ne.setRootCause(e);

            throw ne;

        }

    }

}

/**

 * A name parser for case-sensitive atomic names.

 */

class AtomicNameParser implements NameParser {

    private static final Properties syntax = new Properties();

    public Name parse(String name) throws NamingException {

        return (new CompoundName(name, syntax));

    }

}

/**

 * An enumeration of name / class-name pairs.

 */

class NameClassPairEnumeration implements NamingEnumeration<NameClassPair> {

    private final String[] names;

    private int nextName;       // index into "names"

    NameClassPairEnumeration(String[] names) {

        this.names = names;

        nextName = 0;

    }

    public boolean hasMore() {

        return (nextName < names.length);

    }

    public NameClassPair next() throws NamingException {

        if (!hasMore()) {

            throw (new java.util.NoSuchElementException());

        }

        // Convert name to a one-element composite name, so embedded

        // meta-characters are properly escaped.

        String name = names[nextName++];

        Name cname = (new CompositeName()).add(name);

        NameClassPair ncp = new NameClassPair(cname.toString(),

                                            "java.lang.Object");

        ncp.setNameInNamespace(name);

        return ncp;

    }

    public boolean hasMoreElements() {

        return hasMore();

    }