client/gui/src/XylTelnetConnection.java

   1 //////////////////////////////////////////////////////////////////////////
   2 // Copyright (C) Wang Cong, Apr. 2007.
   3 // Hacked by Zhou Xiao-Wei.
   4 // This program is free software; you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License version 2 as
   6 // published by the Free Software Foundation.
   7 // See COPYING to learn more.
   8 //////////////////////////////////////////////////////////////////////////
   9 import java.net.*;
  10 import java.io.*;
  11
  12 /**
  13  *This class is a subclass of XylFTPConnection.
  14  *@author WANG Cong
  15  *@version 1.7
  16  */
  17 public class XylTelnetConnection{
  18
  19     /**
  20      *The hostname of the server to connect to.
  21      */
  22     private String Host;
  23
  24     /**
  25      *The port to connect to
  26      */
  27     private int ServerPort;
  28
  29     /**
  30      *The port of local host
  31      */
  32
  33     private int SelfPort;
  34     /**
  35      *The timeout when attempting to connect a socket.
  36      */
  37     protected int Timeout;      //in milliseconds
  38
  39     /**
  40      *The writer who inputs the commands.
  41      */
  42     private Writer CmdWriter;
  43
  44     /**
  45      *The reader that reads the echos from the sever.
  46      */
  47     private BufferedReader EchoReader;
  48
  49     /**
  50      *The socket of the command needs to start.
  51      */
  52     private Socket CmdSocket;
  53
  54     /**
  55      *Initializes some values.
  56      */
  57     XylTelnetConnection(){
  58         CmdWriter = null;
  59         EchoReader = null;
  60         CmdSocket = null;
  61         Host = null;
  62         ServerPort = 21;
  63         SelfPort = -1;
  64         Timeout = 30000;        //I don't know whether this is proper. 8(
  65     }
  66
  67     /**
  68      *Initializes some values.
  69      *@param HostName the hostname of the server to connect to
  70      */
  71     XylTelnetConnection(String HostName){
  72         CmdWriter = null;
  73         EchoReader = null;
  74         CmdSocket = null;
  75         Host = HostName;
  76         ServerPort = 21;
  77         SelfPort = -1;
  78         Timeout = 30000;
  79     }
  80
  81     /**
  82      *Gets command from the user.
  83      *@param Command the command that user inputs
  84      *@exception IOException on sending command error
  85      *@see IOException
  86      */
  87     public void SendCommand(String Command) throws IOException{
  88         try{
  89             CmdWriter.write(Command);
  90             CmdWriter.flush();
  91         } catch (IOException e) {
  92             throw e;
  93         }
  94     }
  95     /**
  96      *Gets the string of the IP address of localhost
  97      *Each byte of IP is separated by a _comma_, since
  98      *this is for PORT command, _not_ for any socket.
  99      */
 100     public String GetSelfIP(){
 101         InetAddress ina;
 102         byte[] ipa;
 103         String ip = "";
 104         ina = CmdSocket.getLocalAddress();
 105         ipa = ina.getAddress();
 106         for (int i=0; i< 4; i++) {
 107             ip = ip + (((int)ipa[i])&0xff) + ",";       //I know we have 4 commas!
 108         }
 109         return ip;
 110     }
 111     /**
 112      *Attempts to get an available port of local host for use.
 113      */
 114     public String GetSelfPort() throws IOException {
 115         ServerSocket sk = new ServerSocket(0);
 116         int port = sk.getLocalPort();
 117         sk.close();
 118         SelfPort = port;
 119         int hi, low;
 120         low = port%256;
 121         hi = port/256;
 122         sk.close();
 123         return hi+","+low;
 124     }
 125     /**
 126      *Just returns the port to be used by local host.
 127      */
 128     public int ReturnSelfPort(){
 129         return SelfPort;
 130     }
 131     /**
 132      *Gets echoes from the server.
 133      *@return line the echos from the server
 134      *@exception IOException on read error
 135      */
 136     public String GetEcho() throws IOException{
 137         String line = EchoReader.readLine();
 138         while (line != null && line.length() == 0)
 139             line = EchoReader.readLine();
 140         return line;
 141     }
 142
 143     /**
 144      *Starts to connect with the server.
 145      *@exception Exception on opening connection error
 146      *@see Exception
 147      */
 148     public void OpenConnection() throws Exception{
 149         if(Host==null)
 150             throw new Exception("Unspecified host name.");
 151         CmdSocket = new Socket(Host, ServerPort);
 152         CmdSocket.setSoTimeout(Timeout);
 153         InitStreams();
 154     }
 155
 156     /**
 157      *Initilizes the streams that input and output.
 158      *@exception Exception on errors when initializing streams.
 159      *@see Exception
 160      */
 161     private void InitStreams() throws Exception{
 162         InputStream is = CmdSocket.getInputStream();
 163         EchoReader = new BufferedReader(new InputStreamReader(is));
 164         OutputStream os = CmdSocket.getOutputStream();
 165         CmdWriter = new OutputStreamWriter(os);
 166     }
 167
 168     /**
 169      *Closes the connection with the server.
 170      *@exception Exception on closing connection error
 171      *@see Exception
 172      */
 173     public void CloseConnection() throws Exception{
 174         if(CmdWriter != null) {
 175             CmdWriter.close();
 176             CmdWriter = null;
 177         }
 178         if(EchoReader != null) {
 179             EchoReader.close();
 180             EchoReader = null;
 181         }
 182         if(CmdSocket != null) {
 183             CmdSocket.close();
 184             CmdSocket = null;
 185         }
 186     }
 187
 188     /**
 189      *Sets a new host.
 190      *@param NewHost a new founded host
 191      */
 192     public void SetHost(String NewHost) {
 193         Host = NewHost;
 194     }
 195
 196     /**
 197      *Gets the host name .
 198      *@return the hostname of the server
 199      */
 200     public String GetHost(){
 201         return Host;
 202     }
 203
 204     /**
 205      *Sets a new port.
 206      *@param NewPort a new founded port
 207      */
 208     public void SetPort(int NewPort) {
 209         ServerPort = NewPort;
 210     }
 211
 212     /**
 213      *Gets the port connected with the server.
 214      *@return the number of the current port
 215      */
 216     public int GetPort(){
 217         return ServerPort;
 218     }
 219
 220 }