Is it possible to create more than 1 consumers on InputStream and OutputStream?

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 Strings, ints etc. I am attempting to use DataInputStream and DataOutputStream for Strings,ints and ObjectInputStream, ObjectOutputStream for objects. My program goes into an infinite loop. So should I use ObjectStream's for passingStrings,ints as well and completely omitDataStream`s or is there a workaround available which will allow both Streams to be used on the same socket?

score 0 · Answer 1 · answered Sep 11 '18 at 19:19

0

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

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?

answered Sep 11 '18 at 19:19

Alexandre Dupriez

3,026
20
25

For some functions, I need to transfer `strings` and for some other functions, I need to transfer `objects` via the socket. That's why I am using both DataStream and ObjectStream – Edmund Fitzgerald Sep 12 '18 at 17:20

Is it possible to create more than 1 consumers on InputStream and OutputStream?

1 Answers1