同时将多线程连接到本地主机？

Question

I'm trying to make 2 or more threads write through an output stream to a server-side application at the same time through java sockets.

but instead they are writing in a sequential order..

This MVCE acts the same..

SERVER LISTENER

 public static void main(String[] args) {

            Socket socket=null;
            try{
                ServerSocket serverSocket = new ServerSocket(5050);
                while (true) {

                    logger.warn("listening");
                    socket = serverSocket.accept();

                    new TestingSession(socket).start();
                }
            }  catch(Exception e) {}
}

SERVER THREAD:

    class TestingSession extends Thread {
        private static final Logger logger = Logger.getLogger(Class.class.getName());
        private Socket socket;
        TestingSession(Socket socket) {
                    try {

               DataInputStream dataInputStream = new DataInputStream(socket.getInputStream());
                 this.socket = socket;

                while (!socket.isClosed()) {
                    System.out.println(dataInputStream.readUTF());
               }

        } catch (Exception e) {
        }
    }

}

CLIENT MAIN

public class Run {
    public static void main(String[] args) {

        UpdateTest t1 = new UpdateTest();
        UpdateTest t2 = new UpdateTest();
        t1.start();
        t2.start();
        System.out.println("finished creation");

    }
}

CLIENT THREAD

public class UpdateTest extends Thread {

    public void run() {


        try {

           Socket socket;
            socket = new Socket("127.0.0.1", 5050);
          DataOutputStream dataOutputStream = new DataOutputStream(socket.getOutputStream());
          for(int i=0; i <100;i++){
                Thread.sleep(50);
                dataOutputStream.writeUTF(""+i);
                System.out.println(i);
          }
        }catch(Exception e){
            System.out.println(e.getMessage());
        }

     }}

Client's output :

Finished creation

1 1 2 2 3 3 4 4 5 5

Servers output :

1 2 3 4 5 6 ... 97 99 100

-- exception socket closed.--

listening

1 2 3 4 5 6 .. 99 100

Answer 1

I think you may have just messed up the class definition. My IDE tells me that the instance variable socket in TestingSession is not used. Then I noticed that you wrote your entire server "thread" in the constructor, causing start() to do nothing, and making your server execute only in one single thread.

Change this:

class TestingSession extends Thread {
   private static final Logger logger = Logger.getLogger(Class.class.getName());

   private Socket socket;

   TestingSession( Socket socket ) {
      try {

         DataInputStream dataInputStream = new DataInputStream( socket.getInputStream() );
         this.socket = socket;

         while( !socket.isClosed() ) {
            System.out.println( dataInputStream.readUTF() );
         }

      } catch( Exception e ) {
      }
   }

}

To this:

class TestingSession extends Thread {
   private static final Logger logger = Logger.getLogger(Class.class.getName());

   private Socket socket;

   TestingSession( Socket socket ) {
         this.socket = socket;
   }

   @Override
   public void run() {
      try {
         DataInputStream dataInputStream = new DataInputStream( socket.getInputStream() );
         while( !socket.isClosed() ) {
            System.out.println( dataInputStream.readUTF() );
         }

      } catch( Exception e ) {
      }

   }

}