RMIJRMPServerImpl.java

/*
 * Copyright 2002-2007 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 javax.management.remote.rmi;

import java.io.IOException;
import java.rmi.NoSuchObjectException;
import java.rmi.Remote;
import java.rmi.RemoteException;
import java.rmi.server.RMIClientSocketFactory;
import java.rmi.server.RMIServerSocketFactory;
import java.rmi.server.UnicastRemoteObject;
import java.rmi.server.RemoteObject;
import java.util.Map;
import java.util.Collections;
import javax.security.auth.Subject;

import com.sun.jmx.remote.internal.RMIExporter;

/**
 * <p>An {@link RMIServer} object that is exported through JRMP and that
 * creates client connections as RMI objects exported through JRMP.
 * User code does not usually reference this class directly.</p>
 *
 * @see RMIServerImpl
 *
 * @since 1.5
 */
public class RMIJRMPServerImpl extends RMIServerImpl {
    /**
     * <p>Creates a new {@link RMIServer} object that will be exported
     * on the given port using the given socket factories.</p>
     *
     * @param port the port on which this object and the {@link
     * RMIConnectionImpl} objects it creates will be exported.  Can be
     * zero, to indicate any available port.
     *
     * @param csf the client socket factory for the created RMI
     * objects.  Can be null.
     *
     * @param ssf the server socket factory for the created RMI
     * objects.  Can be null.
     *
     * @param env the environment map.  Can be null.
     *
     * @exception IOException if the {@link RMIServer} object
     * cannot be created.
     *
     * @exception IllegalArgumentException if <code>port</code> is
     * negative.
     */
    public RMIJRMPServerImpl(int port,
                             RMIClientSocketFactory csf,
                             RMIServerSocketFactory ssf,
                             Map<String,?> env)
            throws IOException {

        super(env);

        if (port < 0)
            throw new IllegalArgumentException("Negative port: " + port);

        this.port = port;
        this.csf = csf;
        this.ssf = ssf;
        this.env = (env == null) ? Collections.<String, Object>emptyMap() : env;
    }

    protected void export() throws IOException {
        export(this);
    }

    private void export(Remote obj) throws RemoteException {
        RMIExporter exporter =
            (RMIExporter) env.get(RMIExporter.EXPORTER_ATTRIBUTE);
        if (exporter == null)
            UnicastRemoteObject.exportObject(obj, port, csf, ssf);
        else
            exporter.exportObject(obj, port, csf, ssf);
    }

    private void unexport(Remote obj, boolean force)
            throws NoSuchObjectException {
        RMIExporter exporter =
            (RMIExporter) env.get(RMIExporter.EXPORTER_ATTRIBUTE);
        if (exporter == null)
            UnicastRemoteObject.unexportObject(obj, force);
        else
            exporter.unexportObject(obj, force);
    }

    protected String getProtocol() {
        return "rmi";
    }

    /**
     * <p>Returns a serializable stub for this {@link RMIServer} object.</p>
     *
     * @return a serializable stub.
     *
     * @exception IOException if the stub cannot be obtained - e.g the
     *            RMIJRMPServerImpl has not been exported yet.
     */
    public Remote toStub() throws IOException {
        return RemoteObject.toStub(this);
    }

    /**
     * <p>Creates a new client connection as an RMI object exported
     * through JRMP. The port and socket factories for the new
     * {@link RMIConnection} object are the ones supplied
     * to the <code>RMIJRMPServerImpl</code> constructor.</p>
     *
     * @param connectionId the ID of the new connection. Every
     * connection opened by this connector server will have a
     * different id.  The behavior is unspecified if this parameter is
     * null.
     *
     * @param subject the authenticated subject.  Can be null.
     *
     * @return the newly-created <code>RMIConnection</code>.
     *
     * @exception IOException if the new {@link RMIConnection}
     * object cannot be created or exported.
     */
    protected RMIConnection makeClient(String connectionId, Subject subject)
            throws IOException {

        if (connectionId == null)
            throw new NullPointerException("Null connectionId");

        RMIConnection client =
            new RMIConnectionImpl(this, connectionId, getDefaultClassLoader(),
                                  subject, env);
        export(client);
        return client;
    }

    protected void closeClient(RMIConnection client) throws IOException {
        unexport(client, true);
    }

    /**
     * <p>Called by {@link #close()} to close the connector server by
     * unexporting this object.  After returning from this method, the
     * connector server must not accept any new connections.</p>
     *
     * @exception IOException if the attempt to close the connector
     * server failed.
     */
    protected void closeServer() throws IOException {
        unexport(this, true);
    }

    private final int port;
    private final RMIClientSocketFactory csf;
    private final RMIServerSocketFactory ssf;
    private final Map<String, ?> env;
}