Server Client Multi Thread dengan Java

Pada postingan kali ini saya akan membagikan program java Server client multi thread. Pada server dapat terkoneksi beberapa client sekaligus dalam 1 waktu.
Source Codenya di bawah ini :

Alur Data

Server.java

package server;
import java.io.*;
import java.net.*;
import java.util.Scanner;
public class Server {       private static ServerSocket serverSocket;      private static final int PORT = 1234;     
public static void main(String[] args) throws IOException {          try {              serverSocket = new ServerSocket(PORT);
System.out.println("Server berjalan, menunggu client...");
} catch (IOException ioEx) {              System.out.println("\nTidak dapat mensetup port!");            
System.exit(1);
}          do {
//Menunggu koneksi dari client...
Socket client = serverSocket.accept();
System.out.println("\nClient baru diterima.\n");
//Buat thread untuk menangani komunikasi dengan client ini
//lewatkan socket yang relevan ke contructor dari  thread ini
ClientHandler handler = new ClientHandler(client);            
handler.start();  
//menjalankan thread yang telah dibuat          } while (true);      }
}   class ClientHandler extends Thread {       private Socket client;
private Scanner input;
private PrintWriter output;
public ClientHandler(Socket socket) {
//Set up referensi ke socket yang beraosiasi...
client = socket;        
try {              input = new Scanner(client.getInputStream());
output = new PrintWriter(client.getOutputStream(), true);
} catch (IOException ioEx) {              //ioEx.printStackTrace();          }
}       public void run() {          String received;
do {              //Terima pesan dari client pada input stream socket...              received = input.nextLine();              System.out.println(received);
//Echo-kan pesan kembali ke client pada stream output socket...            
output.println("[" + received + "]");             
//Ulangi sampai client mengirimkan pesan 'QUIT'...          } while (!received.equals("QUIT"));                   try {              if (client != null) {                  System.out.println("Menutup koneksi...");
client.close();            
}        
} catch (IOException ioEx) {              System.out.println("Penutupan koneksi gagal!");        
}
}
}

Sedangkan untuk client-nya di bawah ini :

Client.java

package client;
    import java.io.*;
    import java.net.*;
    import java.util.Scanner;
    public class Client {

        private static InetAddress host;
        private static final int PORT = 1234;
        public static void main(String[] args) {
            try {
                host = InetAddress.getLocalHost();
            } catch (UnknownHostException uhEx) {
                System.out.println("\nHost ID tidak ditemukan!\n");
                System.exit(1);
            }
            sendMessages();
        }
        private static void sendMessages() {
            Socket socket = null;
            try {
                socket = new Socket(host, PORT);
                Scanner networkInput = new Scanner(socket.getInputStream());
                PrintWriter networkOutput = new PrintWriter(socket.getOutputStream(), true);
                //Set up stream untuk masukan dari keyboard...
                Scanner userEntry = new Scanner(System.in);
                String message, response;
                do {
                    System.out.print("Masukkan pesan ('QUIT' untuk keluar): ");
                    message = userEntry.nextLine();
                    //Kirim pesan (message)ke server pada output stream socket...
                    //Terima respon dari server pada stream input socket...
                    networkOutput.println(message);
                    response = networkInput.nextLine();
                    //Tampilkan respon dari server...
                    System.out.println("\nSERVER> " + response);
                } while (!message.equals("QUIT"));
            } catch (IOException ioEx) {
                //ioEx.printStackTrace();
            } finally {
                try {
                    System.out.println("\nMenutup koneksi...");
                    socket.close();
                } catch (IOException ioEx) {
                    System.out.println("Gagal menutup koneksi!");
                    System.exit(1);
                }
            }
        }
    }

Selamat Mencoba!!