1. import java.io.BufferedReader;
2. import java.io.BufferedWriter;
3. import java.io.IOException;
4. import java.io.InputStreamReader;
5. import java.io.OutputStreamWriter;
6. import java.net.Socket;
7. import java.util.Scanner;
8.  
9. public class Client {
10.     private BufferedReader in;
11.     private BufferedWriter out;
12.     private Socket socket;
13.     String userName;
14.     public Client(Socket socket, String username) {
15.         try {
16.             this.socket = socket;
17.             this.in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
18.             this.out = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
19.             this.userName = username;
20.         } catch (IOException e) {
21.             closeEveryThing(in, out, socket);
22.         }
23.     }
24.     public void closeEveryThing(BufferedReader in, BufferedWriter out, Socket socket) {
25.         try {
26.             if (in != null) in.close();
27.             if (out != null) out.close();
28.             if (socket != null) socket.close();
29.         } catch (IOException e) {
30.             e.printStackTrace();
31.         }
32.     }
33.     public void sendMessage() {
34.         try {
35.             out.write(userName);
36.             out.newLine();
37.             out.flush();
38.             Scanner sc = new Scanner(System.in);
39.             while (socket.isConnected()) {
40.                 System.out.print("> ");
41.                 String messageToSend = sc.nextLine();
42.                 out.write(userName + ": "  + messageToSend);
43.                 out.newLine();
44.                 out.flush();
45.             }
46.             sc.close();
47.         } catch (IOException e) {
48.             closeEveryThing(in, out, socket);
49.         }
50.     }
51.     public void listenForMessage() {
52.         Thread thread = new Thread(new Runnable() {
53.             @Override
54.             public void run() {
55.                 String msgFromGroupChat;
56.                 while (socket.isConnected()) {
57.                     try {
58.                         msgFromGroupChat = in.readLine();
59.                         System.out.println(msgFromGroupChat);
60.                     } catch (IOException e) {
61.                         closeEveryThing(in, out, socket);
62.                     }
63.  
64.                 }
65.             }
66.         });
67.         thread.start();
68.     }
69.     public static void main(String[] args) throws IOException {
70.         Scanner sc = new Scanner(System.in);
71.         System.out.print("Enter your username: ");
72.         String username = sc.nextLine();
73.         Socket socket = new Socket("localhost" ,8512);
74.         Client client = new Client(socket, username);
75.         client.sendMessage();
76.         client.listenForMessage();
77.         sc.close();
78.     }
79. }
80.