Java: Writing the same object with new parameters in output stream several times

Question

In a client-server program I have this object:

class MyTestingObject implements Serializable {
    int number;
    void updateParams() {
        number++;
    }
    @Override
    public String toString() {
        return String.format("has value %03d", number);
    }
}

Server makes a new instance of MyTestingObject one time but in an infinite loop it calls updateParams() , prints it and sends it to client (Using ObjectOutputStream ). Client has an infinite loop too which prints received object(Using ObjectInputStream ).

What i expect is :

server:
Sent "has value 1"
Sent "has value 2"
Sent "has value 3"
Sent "has value 4"

client:
Got "has value 1"
Got "has value 2"
Got "has value 3"
Got "has value 4"

But what i get is:

server:
Sent "has value 1"
Sent "has value 2"
Sent "has value 3"
Sent "has value 4"

client:
Got "has value 1"
Got "has value 1"
Got "has value 1"
Got "has value 1"

Why this happens and more important question how should i change it to make it work as i expect?

If it helps tester code is: (I know it's not clean and is not written in best way):

public static void main(String[] args) {
    (new Thread() {
        MyTestingObject serverInstance = new MyTestingObject();

        {
            serverInstance.number = 0;
        }

        @Override
        public void run() {
            try {
                ServerSocket ss = new ServerSocket(8775);
                Socket s = ss.accept();
                Client cl = new Client();
                cl.setSocket(s);
                while (true) {
                    serverInstance.updateParams();
                    cl.sendObject(serverInstance);
                    System.out.printf("Sent \"%s\"\n", serverInstance);
                }
            } catch (IOException ex) {
                Logger.getLogger(NetworkSendSameObjectWithNewValuesSeveralTimes.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    }).start();
    try {
        Client cl = new Client("127.0.0.1", 8775);
        cl.connect();
        while (true) {
            try {
                System.out.printf("Got \"%s\"\n", cl.readObject());
            } catch (IOException | ClassNotFoundException ex) {
                Logger.getLogger(NetworkSendSameObjectWithNewValuesSeveralTimes.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    } catch (IOException ex) {
        Logger.getLogger(NetworkSendSameObjectWithNewValuesSeveralTimes.class.getName()).log(Level.SEVERE, null, ex);
    }
}

Answer 1

Without seeing your Client and Server code I can't be sure, but I suspect the problem is with how you use ObjectOutputStream .

This question is similar to yours with a good answer.