Udpserver不向客户端发送答案

Question

服务器接受来自客户端的请求但客户端没有从服务器获得答案，在服务器上它接受客户端身份验证，但客户端应用程序显示错误消息。

服务器和客户端位于同一个LAN上。

这是服务器的代码：

public class UdpServer extends BaseServer {

public static final int UDP_BUFFER = 10 * 1024; // 10Kb

private static final int NUMBER_USER_INFO_REQUEST_RETRIES = 5;
private static final int SECONDS_TO_CHECK_USER_INFO = 15;

DatagramSocket inSocket = null;
DatagramSocket outSocket = null;

BlockingQueue<DatagramPacket> incomingRequests = null;
BlockingQueue<DatagramPacket> outgoingRequests = null;

HandleIncomingPackets handleIncomingPackets = null;
HandleRequests handleRequests = null;
HandleOutgoingPackets handleOutgoingPackets = null;
HandleUserInfoUpdates handleUserInfoUpdates = null;


public UdpServer() throws IOException {
    this(4445);
}


public UdpServer(int port) throws IOException {
    super();
    inSocket = new DatagramSocket(port);
    outSocket = new DatagramSocket();

    try {
        serverUserInfo = new UserInfo(UserInfo.SERVER_USERNAME, inSocket.getLocalAddress().getHostAddress(), inSocket.getLocalPort());
    } catch (InvalidDataException e) {
        if (DEBUG)
            System.out.println("oops... initialising serverUserInfo");
    }

    incomingRequests = new LinkedBlockingQueue<>();
    outgoingRequests = new LinkedBlockingQueue<>();
}

public void run() {         
    handleIncomingPackets = new HandleIncomingPackets();
    handleRequests = new HandleRequests();
    handleOutgoingPackets = new HandleOutgoingPackets();
    handleUserInfoUpdates = new HandleUserInfoUpdates();


    handleIncomingPackets.start();
    handleRequests.start();
    handleOutgoingPackets.start();
    handleUserInfoUpdates.start();

    System.out.println("Server Started");
}


private class HandleIncomingPackets extends Thread {
    private boolean canRun = true;
    private byte[] buf;
    private DatagramPacket packet;

    @Override
    public void run() {
        while (canRun) {

            buf = new byte[UDP_BUFFER];
            packet = new DatagramPacket(buf, buf.length);

            try {
                inSocket.receive(packet);
            } catch (IOException e2) {
                if (DEBUG)
                    System.out.println("ops... receiving a packet from socket");
                continue;
            }

            incomingRequests.add(packet);
        }
    }

    public void stopHandleMessages() {
        canRun = false;
    }
}

private class HandleOutgoingPackets extends Thread {
    private boolean canRun = true;

    @Override
    public void run() {
        while (canRun) {
            DatagramPacket dp = null;

            try {
                dp = outgoingRequests.take();
            } catch (InterruptedException e1) { }


            if (dp == null)
                continue;

            try {
                outSocket.send(dp);
            } catch (IOException e) {
                if (DEBUG)
                    System.out.println("could not send a message: " + dp.toString());
            }
        }
    }

    public void stopHandleMessages() {
        canRun = false;
    }

}

private class HandleRequests extends Thread {
    private boolean canRun = true;

    @Override
    public void run() {
        while (canRun) {
            DatagramPacket dp = null;

            try {
                dp = incomingRequests.take();
            } catch (InterruptedException e1) { }

            if (dp == null)
                continue;

            String the_msg = new String(dp.getData(), 0, dp.getLength());
            the_msg = the_msg.trim();

            String message_type = null;
            try {
                message_type = Procedures.getMessageType(the_msg);
            } catch (XmlMessageReprException e) {
                if (DEBUG)
                    System.out.println("Cannot get the message type :( " + e.getMessage());
                continue;
            }

            if (message_type == null) {
                if (DEBUG)
                    System.out.println("message type is null");
                continue;
            }

            if (Procedures.isLoginMessage(message_type)) {
                manageLoginRequest(dp);
            } else if (Procedures.isRegisterMessage(message_type)) {
                manageRegisterRequest(dp);
            } else if (Procedures.isLogoutMessage(message_type)) {                  
                manageLogoutRequest(dp);
            } else if (Procedures.isUserInfoAnswerMessage(message_type)) {                  
                manageUserInfoAnswer(dp);
            }

            // do stuff
        }
    }

    public void stopHandleMessages() {
        canRun = false;
    }
}

private class HandleUserInfoUpdates extends Thread {
    boolean canRun = true;

    @Override
    public void run() {

        while (canRun) {

            Calendar c = Calendar.getInstance();
            Date now = c.getTime();

            for (SimpleIMUser simu : registeredUsers) {
                // now - last >= Seconds to check
                // now >= last + seconds to check

                if (!simu.getUser().isOnline())
                    continue;

                c.setTime(simu.last_update);
                c.add(Calendar.SECOND, SECONDS_TO_CHECK_USER_INFO * NUMBER_USER_INFO_REQUEST_RETRIES);
                if (now.after(c.getTime())) {

                    simu.getUser().setOffline();

                    if (DEBUG)
                        System.out.println("HandlerUserInfoUpdates - set "+  simu.getUser() + " offline...");

                    continue;
                }

                c.setTime(simu.last_update);
                c.add(Calendar.SECOND, SECONDS_TO_CHECK_USER_INFO);
                if (now.after(c.getTime())) {

                    sendUserInfoRequest(simu);

                    if (DEBUG)
                        System.out.println("HandlerUserInfoUpdates - send a userInfoRequest... to: " + simu.getUser());
                }
            }

            try {
                Thread.sleep(SECONDS_TO_CHECK_USER_INFO * 1000);
            } catch (InterruptedException e) { }
        }
    }

    public void stopHandleMessages() {
        canRun = false;
    }


}

/* 
 * various requests/messages managers 
 * 
 */
private void sendUserInfoRequest(SimpleIMUser simu) {
    UserInfoRequestMessage uirm = new UserInfoRequestMessage(serverUserInfo);

    String uirmXml = null;
    try {
        uirmXml = uirm.toXML();
    } catch (ParserConfigurationException | TransformerException e1) {
        //unlikely to be here
    }

    DatagramPacket p;
    try {
        p = new DatagramPacket(uirmXml.getBytes(), uirmXml.getBytes().length, 
                                            InetAddress.getByName(simu.getUser().getIp()),
                                            simu.getUser().getPort());
    } catch (UnknownHostException e) {
        /* if there's error... nothing to do */
        return;
    }

    outgoingRequests.add(p);
}

private void manageUserInfoAnswer(DatagramPacket dp) {
    String msg = new String(dp.getData(), 0, dp.getLength());
    UserInfoAnswerMessage uiam;

    try {
        uiam = UserInfoAnswerMessage.fromXML(msg);
    } catch (XmlMessageReprException e) {
        //nothing to do...
        return;
    }

    UserInfo source = uiam.getSource();

    SimpleIMUser simu = getTheUserFromRegistered(source);

    if (simu == null)
        return;

    simu.getUser().locationData(source.hasLocationData());
    simu.getUser().setAltitude(source.getAltitude());
    simu.getUser().setLatitude(source.getLatitude());
    simu.getUser().setLongitude(source.getLongitude());
    simu.getUser().setIP(source.getIp());
    simu.getUser().setPort(source.getPort());
    simu.getUser().setOnline();
    simu.last_update = Calendar.getInstance().getTime();

}

private void manageLogoutRequest(DatagramPacket dp) {
    String request = new String(dp.getData(), 0, dp.getLength());
    LogoutMessage lm = null;

    try {
        lm = LogoutMessage.fromXML(request);
    } catch (XmlMessageReprException e) {
        return;
    }

    UserInfo source = lm.getSource();

    SimpleIMUser s = getTheUserFromRegistered(source);

    if (s == null)
        return;

    s.getUser().setOffline();
    s.last_update = Calendar.getInstance().getTime();

}

private void manageLoginRequest(DatagramPacket packet) {
    String request = new String(packet.getData(), 0, packet.getLength());

    LoginMessage lm = null;
    UserInfo userOfMessage = null;
    String password = null;
    SimpleIMUser s;
    String answer = null;

    InetAddress address;
    int port;

    try {
        lm = LoginMessage.fromXML(request);
    } catch (XmlMessageReprException e1) {
        if (DEBUG) 
            System.out.println("Login message cannot be serialized :(");
    }

    userOfMessage = lm.getUser();
    password = lm.getPassword();

    if (DEBUG) 
        System.out.println("Login message recieved from \"" + userOfMessage.getUsername() +"\"");

    s = getTheUserFromRegistered(userOfMessage);

    if (s == null || (s != null && !s.samePassword(password))) {
        if (DEBUG) 
            System.out.println("Sending REFUSE login to \"" + userOfMessage.getUsername() +"\"");

        try {
            answer = new LoginMessageAnswer(userOfMessage).toXML();
        } catch (ParserConfigurationException | TransformerException e) {
            if (DEBUG) 
                System.out.println("ops... should not be here :(");
        }

        address = packet.getAddress();
        port = packet.getPort();

        outgoingRequests.add(new DatagramPacket(answer.getBytes(), answer.getBytes().length, address, port));
    } else {
        if (DEBUG) 
            System.out.println("Sending ACCEPT login to \"" + userOfMessage.getUsername() +"\"");

        address = packet.getAddress();
        port = packet.getPort();

        s.getUser().locationData(userOfMessage.hasLocationData());
        s.getUser().setAltitude(userOfMessage.getAltitude());
        s.getUser().setLatitude(userOfMessage.getLatitude());
        s.getUser().setLongitude(userOfMessage.getLongitude());
        s.getUser().setIP(address.getHostAddress());
        s.getUser().setPort(port);
        s.getUser().setOnline();
        s.last_update = Calendar.getInstance().getTime();

        try {
            answer = new LoginMessageAnswer(s.getUser(), String.valueOf(s.getUser().hashCode())).toXML();
        } catch (ParserConfigurationException | TransformerException e) { 
            if (DEBUG) 
                System.out.println("ops... making a loginAnswer message");
        }

        outgoingRequests.add(new DatagramPacket(answer.getBytes(), answer.getBytes().length, address, port));

        ListMessage listMessage = new ListMessage();
        fillListMessage(listMessage, s);

        try {
            answer = listMessage.toXML();
        } catch (ParserConfigurationException | TransformerException e) { }

        outgoingRequests.add(new DatagramPacket(answer.getBytes(),  answer.getBytes().length, address, port));

    }
}

private void manageRegisterRequest(DatagramPacket dp) {
    String request = new String(dp.getData(), 0, dp.getLength());
    RegisterMessage rm = null;
    String answer = null;

    try {
        rm = RegisterMessage.fromXML(request);
    } catch (XmlMessageReprException e) {
        if (DEBUG) 
            System.out.println("Register message cannot be serialized :(");                     
    }

    if (DEBUG) 
        System.out.println("Register message recieved from \"" + rm.getUser().getUsername() +"\"");


    if (registeredUsers.contains(new SimpleIMUser(rm.getUser(), "DUMMY")) || rm.getUser().equals(serverUserInfo)) {
        if (DEBUG) 
            System.out.println("Sending REFUSE register to \"" + rm.getUser().getUsername() +"\"");

        try {
            answer = new RegisterMessageAnswer(rm.getUser(), RegisterMessageAnswer.REFUSED).toXML();
        } catch (ParserConfigurationException | TransformerException e) {
            if (DEBUG) 
                System.out.println("ops... should not be here :("); 
        } catch (InvalidDataException e) {
            if (DEBUG) 
                System.out.println("ops... should not be here :("); 
        }                       
    } else {
        if (DEBUG) 
            System.out.println("Sending ACCEPT register to \"" + rm.getUser().getUsername() +"\"");

        rm.getUser().setOffline();
        addUserToRegisteredUsers(new SimpleIMUser(rm.getUser(), rm.getPassword()));

        try {
            answer = new RegisterMessageAnswer(rm.getUser(),RegisterMessageAnswer.ACCEPTED).toXML();
        } catch (ParserConfigurationException | TransformerException e) {
            if (DEBUG) 
                System.out.println("ops... should not be here :("); 
        } catch (InvalidDataException e) {
            if (DEBUG) 
                System.out.println("ops... should not be here :("); 
        }
    }

    outgoingRequests.add(new DatagramPacket(answer.getBytes(), answer.getBytes().length, dp.getAddress(), dp.getPort()));
}

@Override
protected void finalize() throws Throwable {
    handleUserInfoUpdates.stopHandleMessages();
    handleRequests.stopHandleMessages();
    handleOutgoingPackets.stopHandleMessages();
    handleIncomingPackets.stopHandleMessages();

    inSocket.close();
    outSocket.close();
    super.finalize();
}
}

您可以采取任何措施来帮助或告诉我我做错了什么。