是否可以在 InputStream 和 OutputStream 上创建 1 个以上的消费者？

Question

I am implementing a Java project using client-server architecture. My client goes into an infinite loop when connected via socket.

EDIT1: I have changed my client and server programs to minimal, complete and verifiable codes. The issue arises due to having multiple consumers on the same input and output streams (as pointed by the answer below).

Here is my server code:

import java.net.*;
import java.io.*;

class Demo {
    int a;
    String b;

    Demo() {
        a = 10;
        b = "Sample";
    }
}

class Streamsample {
    private ServerSocket serverSocket = null;
    DataInputStream dis = null;
    DataOutputStream dos = null;
    ObjectInputStream ois = null;
    ObjectOutputStream oos = null;

    Streamsample() {
        try{
            serverSocket = new ServerSocket(3000);
            Socket s = serverSocket.accept();
            dis = new DataInputStream(s.getInputStream());
            dos = new DataOutputStream(s.getOutputStream());
            ois = new ObjectInputStream(s.getInputStream());
            oos = new ObjectOutputStream(s.getOutputStream());
            System.out.println(dis.readUTF());

            Demo d = (Demo)ois.readObject();
            System.out.print(d.a + " " + d.b);  
            dis.close();
            dos.close();
            ois.close();
            oos.close();
        }
        catch(Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        Streamsample ss = new Streamsample();
    }
}

Here is my client code:

import java.net.*;
import java.io.*;

class Demo {
    int a;
    String b;

    Demo() {
        a = 10;
        b = "Sample";
    }
}

class Streamclient {
    private Socket s = null;
    DataInputStream dis = null;
    DataOutputStream dos = null;
    ObjectInputStream ois = null;
    ObjectOutputStream oos = null;

    Streamclient() {
        try{
            s = new Socket("localhost",3000);
            dis = new DataInputStream(s.getInputStream());
            dos = new DataOutputStream(s.getOutputStream());
            ois = new ObjectInputStream(s.getInputStream());
            oos = new ObjectOutputStream(s.getOutputStream());

            dos.writeUTF("Hello");
            Demo d = new Demo();
            oos.writeObject(d);

            dis.close();
            dos.close();
            ois.close();
            oos.close();
        }
        catch(Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        Streamclient ss = new Streamclient();
    }
}

The system I am implementing requires my client to send and receive objects as well as String s, int s etc. I am attempting to use DataInputStream and DataOutputStream for String s, int s and ObjectInputStream , ObjectOutputStream for object s. My program goes into an infinite loop. So should I use ObjectStream's for passing String s, int s as well and completely omit DataStream`s or is there a workaround available which will allow both Streams to be used on the same socket?

Answer 1

You are consuming the same streams twice - it cannot work by design. You should only have one consumer for each of your streams, eg:

TicketBooking.oos = new ObjectOutputStream(s.getOutputStream());
TicketBooking.ois = new ObjectInputStream(s.getInputStream());

Why do you need two consumers for each of your input and output streams?