/* * Java(TM) SE 6 version. * Code is the same as 1.0. */import java.net.*;import java.io.*;class TalkServer {    TalkServerThread[] tstList = new TalkServerThread[2];    boolean DEBUG = false;    public static void main(String[] args) {        new TalkServer().start();    }    public void start() {        ServerSocket serverRSocket = null;        int numConnected = 0;        try {            serverRSocket = new ServerSocket(0);            System.out.println("TalkServer listening on rendezvous port: "                               + serverRSocket.getLocalPort());        } catch (IOException e) {            System.err.println("Server could not create server socket for rendezvous.");            return;        }        while (true) {            //Connect to two clients.            while (numConnected < 2) {                TalkServerThread tst;                tst = connectToClient(serverRSocket);                if (tst != null) {                    numConnected++;                    if (tstList[0] == null) {                        tstList[0] = tst;                    } else {                        tstList[1] = tst;                    }                }            } //end while (numConnected < 2) loop            if (DEBUG) {                try {                    System.out.println("tst #0 = " + tstList[0]);                } catch (Exception e) {}                try {                    System.out.println("tst #1 = " + tstList[1]);                } catch (Exception e) {}            }            //If they're really OK, tell them to start writing.            if (everythingIsOK(0) & everythingIsOK(1)) {                for (int i = 0; i < 2; i++) {                    writeToStream("START WRITING!\n----------------------"                                  + "-------------", tstList[i].os);                }            } else {                System.err.println("2 server threads created, but "                                   + "not everything is OK");            }            while (numConnected == 2) {                if (!everythingIsOK(0)) {                    if (DEBUG) {                        System.out.println("Applet #0 is hosed; disconnecting.");                    }                    numConnected--;                    cleanup(tstList[0]);                    tstList[0] = null;                }                if (!everythingIsOK(1)) {                    if (DEBUG) {                        System.out.println("Applet #1 is hosed; disconnecting.");                    }                    numConnected--;                    cleanup(tstList[1]);                    tstList[1] = null;                }                       try {                    Thread.sleep(1000);                } catch (InterruptedException e) {                }             } //end while(numConnected==2) loop            if (DEBUG) {                try {                    System.out.println("Number of connections = " + numConnected);                    System.out.println("tst #0 = " + tstList[0]);                    System.out.println("tst #1 = " + tstList[1]);                } catch (Exception e) {}            }        } //end while (true) loop    }    protected TalkServerThread connectToClient(ServerSocket serverRSocket) {        DataOutputStream os = null;        Socket rendezvousSocket = null;        TalkServerThread tst = null;        //Listen for client connection on the rendezvous socket.        try {            rendezvousSocket = serverRSocket.accept();        } catch (IOException e) {            System.err.println("Accept failed.");            e.printStackTrace();            return null;        }        //Create a thread to handle this connection.        try {            tst = new TalkServerThread(rendezvousSocket, this);            tst.start();        } catch (Exception e) {             System.err.println("Couldn't create TalkServerThread:");            e.printStackTrace();            return null;        }        writeToStream("Successful connection. "                      + "Please wait for second applet to connect...",                      tst.os);        return tst;    }    boolean everythingIsOK(int tstNum) {        TalkServerThread tst = tstList[tstNum];        if (tst == null) {            if (DEBUG) {                System.out.println("TalkServerThread #" + tstNum                                   + " is null");            }            return false;        } else {            if (tst.os == null) {                if (DEBUG) {                    System.out.println("TalkServerThread #" + tstNum                                       + " output stream is null.");                }                return false;            }            if (tst.is == null) {                if (DEBUG) {                    System.out.println("TalkServerThread #" + tstNum                                       + " input stream is null.");                }                return false;            }            if (tst.socket == null) {                if (DEBUG) {                    System.out.println("TalkServerThread #" + tstNum                                       + " socket is null.");                }                return false;            }        }        //try {            //if ((tst.os == null) |                //(tst.is == null) |                //(tst.socket == null)) {                //return false;            //}        //} catch (Exception e) {            //return false;        //}        return true;    }    void cleanup(TalkServerThread tst) {        if (tst != null) {            try {                if (tst.os != null) {                    tst.os.close();                    tst.os = null;                }            } catch (Exception e) {} //Ignore errors            try {                if (tst.is != null) {                    tst.is.close();                    tst.is = null;                }            } catch (Exception e) {} //Ignore errors            try {                if (tst.socket != null) {                    tst.socket.close();                    tst.socket = null;                }            } catch (Exception e) {} //Ignore errors        }    }    public void forwardString(String string, TalkServerThread requestor) {        DataOutputStream clientStream = null;        if (tstList[0] == requestor) {            if (tstList[1] != null) {                clientStream = tstList[1].os;            } else {                if (DEBUG) {                    System.out.println("Applet #0 has a string to forward, "                                       + "but Applet #1 is gone...");                }                //cleanup();                return;            }        } else {            if (tstList[0] != null) {                clientStream = tstList[0].os;            } else {                if (DEBUG) {                    System.out.println("Applet #1 has a string to forward, "                                       + "but Applet #0 is gone...");                }                //cleanup();                return;            }        }        if (clientStream != null) {            writeToStream(string, clientStream);           } else if (DEBUG) {            System.out.println("Can't forward string -- no output stream.");        }    }    public void writeToStream(String string, DataOutputStream stream) {        if (DEBUG) {            System.out.println("TalkServer about to forward data: "                               + string);        }        try {             stream.writeUTF(string);            stream.flush();            if (DEBUG) {                System.out.println("TalkServer forwarded string.");            }        } catch (IOException e) {            System.err.println("TalkServer failed to forward string:");            e.printStackTrace();            //cleanup();            return;        } catch (NullPointerException e) {            System.err.println("TalkServer can't forward string "                               + "since output stream is null.");            //cleanup();            return;        }    }}