tcpserver.java

iiitAccessServer是一个用Java编写的基于规则的企业鉴别系统。它作为一个服务器工作

/*******************************************************************************
 * Copyright (C) 2002, 2003
 * ingenieurbuero fuer innovative informationstechnik (iiit)
 * Dipl.-Ing. Joerg Beckmann, Dortmund, Germany
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program 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 for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * version $Id: TcpServer.java,v 1.14 2003/04/14 20:41:41 joerg Exp $
 ******************************************************************************/

package de.iiit.access.server.plugins.server;

import de.iiit.access.common.api.*;

import de.iiit.access.server.*;
import de.iiit.access.server.api.*;
import de.iiit.access.server.plugins.parser.*;

import de.iiit.xmlconfig.*;
import de.iiit.util.*;

import java.util.regex.*;
import java.util.*;
import java.net.*;
import java.io.*;

import org.apache.log4j.Logger;

/** Implements a TCP/IP server for requesting the AccessServer 
 * @version $Revision: 1.14 $ $Date: 2003/04/14 20:41:41 $
 */
public class TcpServer extends Thread implements ThreadPluginIf
{
    /** CVS Version Tag */
    private static final String vcid = "$Id: TcpServer.java,v 1.14 2003/04/14 20:41:41 joerg Exp $";

    private static final String PORT = "Port";
    
    private static final int DEFAULT_PORT = 54321;
    
    private int port;

    private Logger logger = Logger.getLogger(this.getClass());

    private boolean running = true;
    
    private Vector handlers = new Vector();
    
    private ServerSocket listen = null;
    
    private boolean verifyUser = true;

    private ResolverPluginIf resolver = null;
    
    /** Creates a new instance of TcpServer */
    public TcpServer()
    {
        setName("TcpServer");

        logger.info("TcpServer intantiated.");
    }

    /** Initializes the server
     * @param config the configuration of the server. Currently the only parameter is <CODE>Port</CODE>
     * which defines the port number to listen on for connections. Default is <CODE>1234</CODE>
     */    
    public void initialize(Configuration config)
    {
        port = config.getIntAttribute(PORT, DEFAULT_PORT);
        
        verifyUser = AccessServer.getVerifyUser();        
        resolver = AccessServer.getResolverPlugin();

        logger.info("TcpServer configured on port <" + port + ">.");
    }

    /** The main method of the thread. It is called by the Java runtime environment.
     * This method waits for new connections and creates an instance of the inner class
     * TcpHandler for each new one.
     */    
    public void run()
    {
        try
        {
            logger.info("Starting TcpServer on port " + port);
            listen = new ServerSocket(port);
            
            while (running)
            {
                TcpHandler tcpHandler = new TcpHandler(listen.accept());
                handlers.add(tcpHandler);
            }
        }
        catch (IOException e)
        {
            if (running)
                logger.error("Socket error on port " + port, e);
        }
    }

    /** This method is called by the AccessServer when the background threads should
     * stop because of a shutdown of the AccessServer itself.
     */
    public void shutdown()
    {
        running = false;
        
        try
        {
            listen.close();
        }
        catch (IOException e)
        {
            // Do nothing
        }

        interrupt();
        
        Enumeration enum = handlers.elements();
        
        while (enum.hasMoreElements())
            ((TcpHandler) enum.nextElement()).shutdown();
            
    }
    
    /** Implements the handler for each established connection. */    
    public class TcpHandler extends Thread
    {
        /** CVS Version Tag */
        private static final String vcid = "$Id: TcpServer.java,v 1.14 2003/04/14 20:41:41 joerg Exp $";
    
        private Socket socket = null;
    
        private Logger logger = Logger.getLogger(this.getClass());

        private ExpressionEvaluator evaluator = new ExpressionEvaluator();

        private Pattern pCommandLine;
        
        private String user = null;
    
        private boolean localHostFlag = false;
        
        private boolean running = true;
        
        private boolean ignoreCase = false;
        
        private TcpHandler()
        {
        }
    
        /** Creates a new instance of TcpHandler
         * @param s The socket to use for the communication with the client.
         */
        public TcpHandler(Socket s)
        {
            socket = s;

            setName("TcpHandler-" + socket.getPort());

            start();
        }

        /** This method is called by the AccessServer when the background threads should
         * stop because of a shutdown of the AccessServer itself.
         */        
        protected void shutdown()
        {
            running = false;

            try
            {
                socket.close();
            }
            catch (IOException e)
            {
                // Do nothing
            }
            
            interrupt();
        }
        
        private boolean processLine(PrintStream os, String commandLine)
        {
            boolean result = true;
            
            Matcher mCommandLine = pCommandLine.matcher(commandLine);
                                        
            if (! mCommandLine.find())
            {
                os.println("ERROR 100: Unknown command");
            }
            else
            {
                int count = mCommandLine.groupCount();

                if (count == 3)
                {
                    String cmd      = mCommandLine.group(1).trim();
                    String operator = mCommandLine.group(2);
                    String argument = mCommandLine.group(3).trim();
                           
                    if (ignoreCase)
                        argument = argument.toLowerCase();

                    if (operator.equals("") && argument.equals(""))
                    {
                        if (cmd.equalsIgnoreCase("HELP"))
                        {                            
                            os.println("HELP - This help");
                            os.println("QUIT - Close connection");
                            os.println("SETUSER=<user> - Set user for expressions");
                            os.println("EXPR=<expression> - Evaluate expression");
                            os.println("OK");
                        }
                        else if (cmd.equalsIgnoreCase("QUIT"))
                        {
                            os.println("Closing connection");
                            result = false;
                        }
                        else if (localHostFlag && cmd.equalsIgnoreCase("SHUTDOWN"))
                        {
                            os.println("Closing connection and shutting down");
                            logger.info("Shutdown command recognized");
                            AccessServer.shutDown();
                            result = false;
                        }
                        else    
                        {
                            os.println("ERROR 100: Unknown command");
                        }
                    }
                    else if (! operator.equals("="))
                    {