Java 多线程服务器客户端应用程序

Question

I need to make these code's multithreaded. I searched everywhere but i cant figure it out. Can you guys do it for me ?

Client.java's main method

Socket clientSocket = null;
PrintWriter out = null;
BufferedReader in = null;
String senddata;

try{
    clientSocket = new Socket("localhost",5555);
}catch(IOException e){
    System.out.println("Connection Error!");
}

out = new PrintWriter(clientSocket.getOutputStream(),true);

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

System.out.print("------------------------------------------------------------\nEnter The Data That Will Send The Server = ");

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

while(!(senddata = data.readLine()).equals("STOP")){
    out.println(senddata);
    System.out.println("Response The Client = " + in.readLine());
    System.out.print("------------------------------------------------------------\nEnter The Data That Will Send The Server = ");
}
out.close();
    in.close();
    data.close();
    clientSocket.close();

Answer 1

Server.java's main method

    ServerSocket serverSocket = null;
    Socket clientSocket = null;
    String receivedData;

    try{
        serverSocket = new ServerSocket(5555);
    }catch(IOException e){
        System.out.println("Port Error!");
    }

    clientSocket = serverSocket.accept(); // Bağlantıyı Sağlayan Kod Satırı. Bağlantı Sağlanmadan Bir Alt Satıra Geçilmez.

    PrintWriter out = new PrintWriter(clientSocket.getOutputStream(),true); // Clienta Veri Gönderimi İçin PrintWriter Nesnesi Oluşturuldu!

    BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream())); // Clientden Gelen Verileri Tutan BufferedReader Nesnesi Oluşturuldu!

    while(!(receivedData = in.readLine()).equals("STOP")){
        System.out.println("------------------------------------------------------------\nReceived Data From Client  = " + receivedData);
        System.out.println("Response = " + receivedData);
        out.println(receivedData);
    }
    out.close();
    in.close();
    serverSocket.close();
    clientSocket.close();