java Connection reset error

Question

I am quite a newbie to Java. Please excuse me if you find this as a very basic question.There are many answers available already in stack overflow about this and I went through almost all the possible helps i can get in Stack overflow and also in some other forums. Unfortunately none of them helped me.

I have client/server program in which the client send a string to server and server just attaches another string to the string sent by client and sends it back to the client.

Server program looks like this.

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class server {

    public static void main(String[] args) {

        try
        {
            ServerSocket server = new ServerSocket(7300);
            Socket s = server.accept();
            DataInputStream inp = new DataInputStream(s.getInputStream());
            DataOutputStream out = new DataOutputStream(s.getOutputStream());
            String str =inp.readUTF();
            str = str+"  buddy!";
            out.writeUTF(str);



        }
        catch(Exception e)
        {
            e.printStackTrace();
        }

    }

}

Client looks like This.

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.net.*;

public class client {

    public static void main(String[] args) {
        try
        {
            Socket s = new Socket("192.168.1.3",7300);
            DataInputStream inp = new DataInputStream(s.getInputStream());
            DataOutputStream out = new DataOutputStream(s.getOutputStream());

            out.writeUTF("hi");
            System.out.println(inp.readUTF());
            Thread.sleep(2000);
            out.writeUTF("hello");
            System.out.println(inp.readUTF());


        }

        catch(Exception e)
        {
            e.printStackTrace();
        }
    }

}

Everything works fine while client writes "hi" and when client starts sending "hello" i am getting Connection reset error. I am not getting what mistake am i doing please help me in resolving this.

The output with the error i am getting looks like this.

hi  buddy!
java.net.SocketException: Connection reset by peer: socket write error
    at java.net.SocketOutputStream.socketWrite0(Native Method)
    at java.net.SocketOutputStream.socketWrite(Unknown Source)
    at java.net.SocketOutputStream.write(Unknown Source)
    at java.io.DataOutputStream.write(Unknown Source)
    at java.io.DataOutputStream.writeUTF(Unknown Source)
    at java.io.DataOutputStream.writeUTF(Unknown Source)
    at sokry.client.main(client.java:18)

Answer 1

In your server example, readUTF is only called once on the DataInputStream, even though the client wrote to the DataOutputStream twice. Thus, simply adding

str = inp.readUTF();
str = str + "  buddy!";
out.writeUTF(str);

to your server example, after the last out.writeUTF(str), will solve your problem.