/*

 * Copyright (c) 1996, 2005, 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 sun.rmi.transport.proxy;

import java.io.BufferedInputStream;

import java.io.IOException;

import java.net.ServerSocket;

import java.net.Socket;

import sun.rmi.runtime.Log;

/**

 * The HttpAwareServerSocket class extends the java.net.ServerSocket

 * class.  It behaves like a ServerSocket, except that if

 * the first four bytes of an accepted socket are the letters "POST",

 * then it returns an HttpReceiveSocket instead of a java.net.Socket.

 * This means that the accept method blocks until four bytes have been

 * read from the new socket's input stream.

 */

class HttpAwareServerSocket extends ServerSocket {

    /**

     * Create a server socket on a specified port.

     * @param port the port

     * @exception IOException IO error when opening the socket.

     */

    public HttpAwareServerSocket(int port) throws IOException

    {

        super(port);

    }

    /**

     * Create a server socket, bind it to the specified local port

     * and listen to it.  You can connect to an annonymous port by

     * specifying the port number to be 0.  <i>backlog</i> specifies

     * how many connection requests the system will queue up while waiting

     * for the ServerSocket to execute accept().

     * @param port the specified port

     * @param backlog the number of queued connect requests pending accept

     */

    public HttpAwareServerSocket(int port, int backlog) throws IOException

    {

        super(port, backlog);

    }

    /**

     * Accept a connection. This method will block until the connection

     * is made and four bytes can be read from the input stream.

     * If the first four bytes are "POST", then an HttpReceiveSocket is

     * returned, which will handle the HTTP protocol wrapping.

     * Otherwise, a WrappedSocket is returned.  The input stream will be

     * reset to the beginning of the transmission.

     * In either case, a BufferedInputStream will already be on top of

     * the underlying socket's input stream.

     * @exception IOException IO error when waiting for the connection.

     */

    public Socket accept() throws IOException

    {

        Socket socket = super.accept();

        BufferedInputStream in =

            new BufferedInputStream(socket.getInputStream());

        RMIMasterSocketFactory.proxyLog.log(Log.BRIEF,

            "socket accepted (checking for POST)");

        in.mark(4);

        boolean isHttp = (in.read() == 'P') &&

                         (in.read() == 'O') &&

                         (in.read() == 'S') &&

                         (in.read() == 'T');

        in.reset();

        if (RMIMasterSocketFactory.proxyLog.isLoggable(Log.BRIEF)) {

            RMIMasterSocketFactory.proxyLog.log(Log.BRIEF,

                (isHttp ? "POST found, HTTP socket returned" :

                          "POST not found, direct socket returned"));

        }

        if (isHttp)

            return new HttpReceiveSocket(socket, in, null);

        else

            return new WrappedSocket(socket, in, null);

    }

    /**

     * Return the implementation address and implementation port of

     * the HttpAwareServerSocket as a String.

     */

    public String toString()

    {

        return "HttpAware" + super.toString();

    }

}