Java for Programmers: Lab 15

This is the client implementation for Lab 15. The server implementation, which you don't need to create, is here.

The Lab Instructions are:

1. Create a ChatClient Class. Chat Client will:

• Have a main method
• Set a username variable based on a program argument
• Create a new Socket
• Create and start two new Threads: ReaderThread and WriterThread

2. Create a WriterThread class. It will:

• Supply a contructor that will take a name [String] and a Socket
• Create a BufferedReader to read from System.in
• Create a PrintWriter to write to the Socket.
• Supply a while loop that reads from Standard Input and writes to the Socket. The message received from Standard Input should prepend the username to itself, plus a >, so that the message sent to the Socket takes the form: username> Message Typed.

3. Create a ThreadReader class that:

• Supplies a Constructor which takes a Socket.
• Creates a continuous loop that reads from the Socket and prints out the value written [System.out.println]

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

public class ChatClient {

  public static void main(String[] args) {
     String name = "Anonymous";

     if (args.length > 0) {
        name = args[0];
      }
  
   try {
     Socket sock = new Socket("204.49.73.220", 2424);
     Thread t = new Thread(new ReadThread(sock));
     Thread t2 = new Thread(new WriteThread(sock, name));
     t.start();
     t2.start();
   }

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

class WriteThread implements Runnable {

  Socket sock;
  String name;

  public void run() {
    try {
 
      PrintWriter out = new PrintWriter(new OutputStreamWriter(sock.getOutputStream()));
      BufferedReader inStream = new BufferedReader(new InputStreamReader(System.in));
      
     while (true) {
       String lineVal;

        if ((lineVal = inStream.readLine()) != null) {
          out.println(name+"> "+lineVal);
          out.flush();
         }
      }
    }

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

  }

  WriteThread(Socket sock, String name) {
    this.sock = sock;
    this.name = name;
  }
}
                  
class ReadThread implements Runnable {
   Socket sock;
 
 public void run() {
  try {
    while (true) {
       BufferedReader br = new BufferedReader(new InputStreamReader(sock.getInputStream()));
       String s = br.readLine();
       System.out.println(s);
     }
   }
   catch(Exception e) {
     e.printStackTrace();
    }
  }
 ReadThread(Socket sock) {
   this.sock = sock;
  }
}