socketは2台のコンピュータを接続してjavaを通信します

ネットで見て、テストに成功して、書きます
サーバ側

import java.net.*;
import java.io.*;
 
public class Server {
 
    private ServerSocket server;
    private Socket client;
 
    public Server() {
        boolean flag = true;
        try {
            server = new ServerSocket(8888);    //  
            System.out.println("            ......");
            while (flag) {
                client = server.accept();   //  
                new ServerThread(client).start();
            }
            server.close();
        } catch (Exception e) {
        }
    }
 
    public static void main(String[] args) {
        new Server();
    }
 
    private class ServerThread extends Thread {
 
        private Socket clientThread;
        private PrintStream out;
        private BufferedReader in;
        private boolean flag = true;
 
        public ServerThread(Socket client) {
            this.clientThread = client;
            System.out.println("            ，    ！！");
        }
 
        public void run() {
            try {
                /*
                 *     ：      300 ，      300               
                 *                ，              ，        
                 */
                clientThread.setSoTimeout(300000);
                out = new PrintStream(client.getOutputStream());
                in = new BufferedReader(new InputStreamReader(client.getInputStream()));
                while (flag) {
                    String str = in.readLine(); //  
                    System.out.println("   ：" + str);
                    out.println("           ！！");
                }
                client.close();
            } catch (Exception e) {
                //         ，       
                if (e.getMessage() == "Connection reset") {
                    System.out.println("        ！！");
                }
            }
        }
    }
}

クライアント

import java.net.*;
import java.io.*;
 
public class Client {
 
    private Socket client;
 
    public Client() {
        try {
            System.out.println("       ......");
 
            client = new Socket("192.168.218.168", 8888);    //  
            BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
            BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
            PrintStream out = new PrintStream(client.getOutputStream());;
            boolean flag = true;
 
            System.out.println("       ，    ！！");
 
            while (flag) {
                System.out.printf("     ：");
                out.println(input.readLine());  //  
                //         
                if (isConnected()) {
                    System.out.println("    ！！");
                    System.out.println("  ：" + in.readLine());
                } else {
                    System.out.println("    ！！");
                    System.out.println("        ！！");
                    client.close();
                    break;
                }
            }
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }
 
    //            ，
    //  OutputStream        ，                 
    //          ，   sendUrgenData
    public boolean isConnected() {
        try {
            client.sendUrgentData(0xFF);
            return true;
        } catch (Exception e) {
            e.printStackTrack();
            return false;
        }
    }
 
    public static void main(String[] args) {
        new Client();
    }
}