java学习之网络编程之echo程序

服务端的实现

 package com.gh.echo;
 import java.io.*;
 import java.net.*;
 /**
  * echo服务器程序
  * 实现 不断接收字符串 ，然后返回一个echo+字符串
  * 服务程序写成多线程
  * @author ganhang
  *
  */
 public class EchoServerDemo {
     public static void main(String[] args) {
         try {
             ServerSocket ss = new ServerSocket(8000);
             System.out.println("服务器已启动。");
             int i=1;
             while (true) {
                 System.out.println("服务器正在等待连接...");
                 Socket s = ss.accept();
                 new Thread(new UserThread(s),"用户"+i++).start();//来一个用户启动一个线程
             }
         } catch (IOException e) {
             e.printStackTrace();
         }
     }
 }
 /**
  * 用户线程
  * @author ganhang
  */
 class UserThread implements Runnable{
     private Socket s;
     public UserThread(Socket s) {
         this.s=s;
     }
     @Override
     public void run() {
         System.out.println(Thread.currentThread().getName()+"-已连接");
         try{
         BufferedReader br=new BufferedReader(new InputStreamReader(s.getInputStream()));
         BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
         while(true){//循环读入知道读入bye
             String info=br.readLine();//因为是读一行所以客服端发送过来的字符串必须有"\n"换行符
             System.out.println(info);
             if("".equals(info)||"bye".equals(info)){
                 break;
             }else{
                 bw.write("echo:你好"+Thread.currentThread().getName()+"\n");//客服端用的读一行所以这边末尾加换行符
                 bw.flush();//缓存流必须刷新
             }
         }
         br.close();
         bw.close();
         }catch(IOException e){
             e.printStackTrace();
         }
     }

 }

客户端的实现

 package com.gh.echo;

 import java.io.BufferedReader;
 import java.io.BufferedWriter;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.OutputStreamWriter;
 import java.net.Socket;
 import java.util.Scanner;
 /**
  * echo客户端
  * 实现从控制台写字符串发送给服务器，接收服务器发回来的字符串
  * @author ganhang
  *
  */
 public class EchoClientDemo {

     public static void main(String[] args) {
         try {
             Socket sk=new Socket("",8000);
             System.out.println("与服务器连接成功。");
             Scanner sc=new Scanner(System.in);
             BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(sk.getOutputStream()));
             BufferedReader br=new BufferedReader(new InputStreamReader(sk.getInputStream()));
             while(true){
                 System.out.println("请输入文字：");
                 String info=sc.next();
                 if("bye".equals(info)){
                     break;
                 }else{
                     bw.write(info+"\n");
                     bw.flush();
                     System.out.println(br.readLine());
                 }
             }
             bw.close();
             br.close();
         } catch (IOException e) {
             e.printStackTrace();
         }

     }
 }