Client和Server双端通信

import java.net.*;
import java.io.*;
import java.util.Scanner;

class server {
    public static void main(String[] args) {
        try {
            ServerSocket ss = new ServerSocket(4321);
            System.out.println("Server OK");
            while(true) {
                Socket s = ss.accept();
                InputStreamReader ins  = new InputStreamReader(s.getInputStream());
                BufferedReader in = new BufferedReader(ins);
                String x = in.readLine();
                System.out.println("Info from client: " + x);
                PrintStream out = new PrintStream(s.getOutputStream());
                out.println("hello client");
                in.close();
                out.close();
                s.close();
            }
        } catch(IOException E) {}
    }
}

class client {
    public static void main(String[] args) {
        try {
            Socket s = new Socket("127.0.0.1",4321);
            PrintStream out = new PrintStream(s.getOutputStream());
            String c = "ACM";
            out.println(c);
            InputStreamReader ins = new InputStreamReader(s.getInputStream());
            BufferedReader in = new BufferedReader(ins);
            String x = in.readLine();
            System.out.println("Info from Server: " + x);
            out.close();
            in.close();
            s.close();
        } catch(IOException e) {}
    }
}