单片机通过TCP⼀IP向计算机传输数据。我用java怎么写一个接受的小程序！

package com.cep.usercenter.sys;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Date;

public class RunUserCenterSystem {

public static void main(String[] args) {

try {
ServerSocket ss = new ServerSocket(51818);
while (true) {
Socket socket = ss.accept();
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));

String line = in.readLine();
if("stop".trim().equalsIgnoreCase(line)){
if(ctx != null){
ctx.stop();
ctx.close();
System.exit(0);
}
}else{
System.out.println("接收的数据为: "+line);
}
in.close();
socket.close();
}
} catch (Exception e) {
}
}
}