网络编程模型

多线程回声（Echo）模型:

import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;

public class EchoSrever {
    private static class MyThread implements Runnable{
        private Socket client;
        public MyThread(Socket client){
            this.client=client;
        }
        @Override
        public void run() {
            try{
            Scanner scan = new Scanner(client.getInputStream());
            scan.useDelimiter("\n");
            PrintStream out = new PrintStream(client.getOutputStream());
            boolean flag = true;
            while (flag) {
                if (scan.hasNext()) {
                    String str = scan.next().trim();
                    if ("byebye".equalsIgnoreCase(str)) {
                        out.println("BYEBYE!!!");
                        flag = false;
                        break;
                    }
                    out.println("Echo:" + str);
                }
            }
            out.close();
            scan.close();
            }catch(Exception e){
                
            }
        }
        
    }
    public static void main(String[] args) throws Exception {
        ServerSocket server = new ServerSocket(8888);
    boolean flag = true;
        while (flag) {
            Socket client = server.accept();
            new Thread(new MyThread(client)).start();
        }
        server.close();
    }
}

import java.io.IOException;
import java.io.PrintStream;
import java.net.Socket;
import java.util.Scanner;

public class EchoSocket {
    public static void main(String[] args) throws Exception, IOException {
        Socket client = new Socket("localhost",8888);
        Scanner keyScan = new Scanner (System.in);
        keyScan.useDelimiter("\n");
        Scanner netScan = new Scanner (client.getInputStream());
        netScan.useDelimiter("\n");
        PrintStream out = new PrintStream(client.getOutputStream());
        boolean flag = true;
        while(flag){
            System.out.println("输入要发送的内容：");
            String str =null;
            if(keyScan.hasNext()){
                str = keyScan.next().trim();
                out.println(str);
                if (netScan.hasNext()) {
                    System.out.println(netScan.next());
                }
            }
            if("byebye".equalsIgnoreCase(str)){
                flag=false;
            }
        }
        out.close();
        netScan.close();
        keyScan.close();
    }
}