Java examples for Network:ServerSocket
Knock Knock client and server
import java.net.*; import java.io.*; public class KKMultiServer { public static void main(String[] args) throws IOException { if (args.length != 1) { System.err.println("Usage: java KKMultiServer <port number>"); System.exit(1); } int portNumber = Integer.parseInt(args[0]); boolean listening = true; try (ServerSocket serverSocket = new ServerSocket(portNumber)) { while (listening) { new KKMultiServerThread(serverSocket.accept()).start(); } } catch (IOException e) { System.err.println("Could not listen on port " + portNumber); System.exit(-1); } } } class KKMultiServerThread extends Thread { private Socket socket = null; public KKMultiServerThread(Socket socket) { super("KKMultiServerThread"); this.socket = socket; } public void run() { try (PrintWriter out = new PrintWriter(socket.getOutputStream(), true); BufferedReader in = new BufferedReader( new InputStreamReader(socket.getInputStream()));) { String inputLine, outputLine; KnockKnockProtocol kkp = new KnockKnockProtocol(); outputLine = kkp.processInput(null); out.println(outputLine); while ((inputLine = in.readLine()) != null) { outputLine = kkp.processInput(inputLine); out.println(outputLine); if (outputLine.equals("Bye")) break; } socket.close(); } catch (IOException e) { e.printStackTrace(); } } } /* * Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of Oracle or the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ --- HTML <p>KnockKnockClient.java</p> --- Code import java.io.*; import java.net.*; public class KnockKnockClient { public static void main(String[] args) throws IOException { if (args.length != 2) { System.err .println("Usage: java EchoClient <host name> <port number>"); System.exit(1); } String hostName = args[0]; int portNumber = Integer.parseInt(args[1]); try (Socket kkSocket = new Socket(hostName, portNumber); PrintWriter out = new PrintWriter( kkSocket.getOutputStream(), true); BufferedReader in = new BufferedReader( new InputStreamReader(kkSocket.getInputStream()));) { BufferedReader stdIn = new BufferedReader( new InputStreamReader(System.in)); String fromServer; String fromUser; while ((fromServer = in.readLine()) != null) { System.out.println("Server: " + fromServer); if (fromServer.equals("Bye.")) break; fromUser = stdIn.readLine(); if (fromUser != null) { System.out.println("Client: " + fromUser); out.println(fromUser); } } } catch (UnknownHostException e) { System.err.println("Don't know about host " + hostName); System.exit(1); } catch (IOException e) { System.err.println("Couldn't get I/O for the connection to " + hostName); System.exit(1); } } } /* * Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of Oracle or the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ --- HTML <p>KnockKnockProtocol.java</p> --- Code import java.net.*; import java.io.*; public class KnockKnockProtocol { private static final int WAITING = 0; private static final int SENTKNOCKKNOCK = 1; private static final int SENTCLUE = 2; private static final int ANOTHER = 3; private static final int NUMJOKES = 5; private int state = WAITING; private int currentJoke = 0; private String[] clues = { "Turnip", "Little Old Lady", "Atch", "Who", "Who" }; private String[] answers = { "Turnip the heat, it's cold in here!", "I didn't know you could yodel!", "Bless you!", "Is there an owl in here?", "Is there an echo in here?" }; public String processInput(String theInput) { String theOutput = null; if (state == WAITING) { theOutput = "Knock! Knock!"; state = SENTKNOCKKNOCK; } else if (state == SENTKNOCKKNOCK) { if (theInput.equalsIgnoreCase("Who's there?")) { theOutput = clues[currentJoke]; state = SENTCLUE; } else { theOutput = "You're supposed to say \"Who's there?\"! " + "Try again. Knock! Knock!"; } } else if (state == SENTCLUE) { if (theInput.equalsIgnoreCase(clues[currentJoke] + " who?")) { theOutput = answers[currentJoke] + " Want another? (y/n)"; state = ANOTHER; } else { theOutput = "You're supposed to say \"" + clues[currentJoke] + " who?\"" + "! Try again. Knock! Knock!"; state = SENTKNOCKKNOCK; } } else if (state == ANOTHER) { if (theInput.equalsIgnoreCase("y")) { theOutput = "Knock! Knock!"; if (currentJoke == (NUMJOKES - 1)) currentJoke = 0; else currentJoke++; state = SENTKNOCKKNOCK; } else { theOutput = "Bye."; state = WAITING; } } return theOutput; } } /* * Copyright (c) 1995, 2008, Oracle and/or its affiliates. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of Oracle or the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ --- HTML <p>KnockKnockServer.java</p> --- Code import java.net.*; import java.io.*; public class KnockKnockServer { public static void main(String[] args) throws IOException { if (args.length != 1) { System.err .println("Usage: java KnockKnockServer <port number>"); System.exit(1); } int portNumber = Integer.parseInt(args[0]); try (ServerSocket serverSocket = new ServerSocket(portNumber); Socket clientSocket = serverSocket.accept(); PrintWriter out = new PrintWriter( clientSocket.getOutputStream(), true); BufferedReader in = new BufferedReader( new InputStreamReader(clientSocket.getInputStream()));) { String inputLine, outputLine; // Initiate conversation with client KnockKnockProtocol kkp = new KnockKnockProtocol(); outputLine = kkp.processInput(null); out.println(outputLine); while ((inputLine = in.readLine()) != null) { outputLine = kkp.processInput(inputLine); out.println(outputLine); if (outputLine.equals("Bye.")) break; } } catch (IOException e) { System.out .println("Exception caught when trying to listen on port " + portNumber + " or listening for a connection"); System.out.println(e.getMessage()); } } } /* * Copyright (c) 1995, 2014, Oracle and/or its affiliates. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of Oracle or the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */