Learning Java Program

import java.io.*; 

import java.net.*; 

class ChatClient extends Thread 

{ 

    Socket s; 

    static PrintWriter out; 

    static BufferedReader read,in; 

    Thread t;

    ChatClient() throws Exception 

    { 

        s = new Socket("127.0.0.1",5000); 

        System.out.println("client connected to server");  

        read = new BufferedReader(new InputStreamReader(System.in)); 

        in=new BufferedReader(new InputStreamReader(s.getInputStream())); 

        out=new PrintWriter(s.getOutputStream()); 

        t=new Thread(this); 

        t.start(); 

    } 

     

    public void run() 

    { 

        String str1; 

        while(true) 

        { 

            try 

            { 

                      str1=in.readLine(); 

                      System.out.println("\n"+"From server: "+str1); 

                } 

                catch(Exception e) 

                { 

                       System.out.println(e); 

            } 

        } 

    }

    public static void main(String args[]) throws Exception 

    { 

        String str2; 

        new ChatClient(); 

        while(true) 

        { 

            str2=read.readLine(); 

            out.println(str2); 

            out.flush();   

           } 

    } 

}

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

class ChatServerTCP extends Thread
{
    ServerSocket server;
    Socket s;
    static PrintWriter out;
    static BufferedReader read,in;
    Thread t;

ChatServerTCP() throws Exception
{
    server = new ServerSocket(5000);
    System.out.println("Server is waiting for client");
    s=server.accept();
    System.out.println("connection is established "+s.getInetAddress());
    read = new BufferedReader(new InputStreamReader(System.in));
    in=new BufferedReader(new InputStreamReader(s.getInputStream()));
    out=new PrintWriter(s.getOutputStream());
    t=new Thread(this);
    t.start();
}

public void run()
{
    String str1;
    while(true)
    {
        try
            {
                  str1=in.readLine();
                  System.out.println("\n"+"From client: "+str1);
            }
            catch(Exception e)
            {
                   System.out.println(e);
            }
      }
}

public static void main(String args[]) throws Exception
{
    ChatServerTCP cs = new ChatServerTCP();
    String str2;
    while(true)
    {
             str2=read.readLine();
             out.println(str2);
             out.flush(); 
       }
}
}

client connected to server
hi

From server: hi da

how r u?

From server: fine

Server is waiting for client 

connection is established /127.0.0.1 

From client: hi 

hi da

From client:

From client: how r u? 

fine