src/com/googlecode/lanterna/terminal/ansi/TelnetTerminalServer.java

   1 /*
   2  * This file is part of lanterna (http://code.google.com/p/lanterna/).
   3  *
   4  * lanterna is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU Lesser General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  *
  17  * Copyright (C) 2010-2015 Martin
  18  */
  19 package com.googlecode.lanterna.terminal.ansi;
  20
  21 import java.io.IOException;
  22 import java.net.ServerSocket;
  23 import java.net.Socket;
  24 import java.nio.charset.Charset;
  25 import javax.net.ServerSocketFactory;
  26
  27 /**
  28  * This class implements a Telnet server, capable of accepting multiple clients and presenting each one as their own
  29  * Terminal. You need to tell it at least what port to listen on and then it create a Server socket listening for
  30  * incoming connections. Use {@code acceptConnection()} to wait for the next incoming connection, it will be returned as
  31  * a {@code TelnetTerminal} object that represents the client and which will be the way for the server to send content
  32  * to this client. Next connecting client (through {@code acceptConnection()} will get a different
  33  * {@code TelnetTerminal}, i.e. their content will not be in sync automatically but considered as two different
  34  * terminals.
  35  * @author martin
  36  * @see TelnetTerminal
  37  * @see <a href="http://en.wikipedia.org/wiki/Telnet">Wikipedia</a>
  38  */
  39 @SuppressWarnings("WeakerAccess")
  40 public class TelnetTerminalServer {
  41     private final Charset charset;
  42     private final ServerSocket serverSocket;
  43
  44     /**
  45      * Creates a new TelnetTerminalServer on a specific port
  46      * @param port Port to listen for incoming telnet connections
  47      * @throws IOException If there was an underlying I/O exception
  48      */
  49     public TelnetTerminalServer(int port) throws IOException {
  50         this(ServerSocketFactory.getDefault(), port);
  51     }
  52
  53     /**
  54      * Creates a new TelnetTerminalServer on a specific port, using a certain character set
  55      * @param port Port to listen for incoming telnet connections
  56      * @param charset Character set to use
  57      * @throws IOException If there was an underlying I/O exception
  58      */
  59     public TelnetTerminalServer(int port, Charset charset) throws IOException {
  60         this(ServerSocketFactory.getDefault(), port, charset);
  61     }
  62
  63     /**
  64      * Creates a new TelnetTerminalServer on a specific port through a ServerSocketFactory
  65      * @param port Port to listen for incoming telnet connections
  66      * @param serverSocketFactory ServerSocketFactory to use when creating the ServerSocket
  67      * @throws IOException If there was an underlying I/O exception
  68      */
  69     public TelnetTerminalServer(ServerSocketFactory serverSocketFactory, int port) throws IOException {
  70         this(serverSocketFactory, port, Charset.defaultCharset());
  71     }
  72
  73     /**
  74      * Creates a new TelnetTerminalServer on a specific port through a ServerSocketFactory with a certain Charset
  75      * @param serverSocketFactory ServerSocketFactory to use when creating the ServerSocket
  76      * @param port Port to listen for incoming telnet connections
  77      * @param charset Character set to use
  78      * @throws IOException If there was an underlying I/O exception
  79      */
  80     public TelnetTerminalServer(ServerSocketFactory serverSocketFactory, int port, Charset charset) throws IOException {
  81         this.serverSocket = serverSocketFactory.createServerSocket(port);
  82         this.charset = charset;
  83     }
  84
  85     /**
  86      * Returns the actual server socket used by this object. Can be used to tweak settings but be careful!
  87      * @return Underlying ServerSocket
  88      */
  89     public ServerSocket getServerSocket() {
  90         return serverSocket;
  91     }
  92
  93     /**
  94      * Waits for the next client to connect in to our server and returns a Terminal implementation, TelnetTerminal, that
  95      * represents the remote terminal this client is running. The terminal can be used just like any other Terminal, but
  96      * keep in mind that all operations are sent over the network.
  97      * @return TelnetTerminal for the remote client's terminal
  98      * @throws IOException If there was an underlying I/O exception
  99      */
 100     public TelnetTerminal acceptConnection() throws IOException {
 101         Socket clientSocket = serverSocket.accept();
 102         clientSocket.setTcpNoDelay(true);
 103         return new TelnetTerminal(clientSocket, charset);
 104     }
 105
 106     /**
 107      * Closes the server socket, accepting no new connection. Any call to acceptConnection() after this will fail.
 108      * @throws IOException If there was an underlying I/O exception
 109      */
 110     public void close() throws IOException {
 111         serverSocket.close();
 112     }
 113 }