java学习之网络编程之echo程序

服务端的实现

 1 package com.gh.echo;
 2 import java.io.*;
 3 import java.net.*;
 4 /**
 5  * echo服务器程序
 6  * 实现 不断接收字符串 ，然后返回一个echo+字符串
 7  * 服务程序写成多线程
 8  * @author ganhang
 9  * 
10  */
11 public class EchoServerDemo {
12     public static void main(String[] args) {
13         try {
14             ServerSocket ss = new ServerSocket(8000);
15             System.out.println("服务器已启动。");
16             int i=1;
17             while (true) {
18                 System.out.println("服务器正在等待连接...");
19                 Socket s = ss.accept();
20                 new Thread(new UserThread(s),"用户"+i++).start();//来一个用户启动一个线程
21             }
22         } catch (IOException e) {
23             e.printStackTrace();
24         }
25     }
26 }
27 /**
28  * 用户线程
29  * @author ganhang
30  */
31 class UserThread implements Runnable{
32     private Socket s;
33     public UserThread(Socket s) {
34         this.s=s;
35     }
36     @Override
37     public void run() {
38         System.out.println(Thread.currentThread().getName()+"-已连接");
39         try{
40         BufferedReader br=new BufferedReader(new InputStreamReader(s.getInputStream()));
41         BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
42         while(true){//循环读入知道读入bye
43             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"
"换行符
44             System.out.println(info);
45             if("".equals(info)||"bye".equals(info)){
46                 break;
47             }else{
48                 bw.write("echo:你好"+Thread.currentThread().getName()+"
");//客服端用的读一行所以这边末尾加换行符
49                 bw.flush();//缓存流必须刷新
50             }
51         }
52         br.close();
53         bw.close();
54         }catch(IOException e){
55             e.printStackTrace();
56         }
57     }
58     
59 }

客户端的实现

 1 package com.gh.echo;
 2 
 3 import java.io.BufferedReader;
 4 import java.io.BufferedWriter;
 5 import java.io.IOException;
 6 import java.io.InputStreamReader;
 7 import java.io.OutputStreamWriter;
 8 import java.net.Socket;
 9 import java.util.Scanner;
10 /**
11  * echo客户端
12  * 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
13  * @author ganhang
14  *
15  */
16 public class EchoClientDemo {
17     
18     public static void main(String[] args) {
19         try {
20             Socket sk=new Socket("",8000);
21             System.out.println("与服务器连接成功。");
22             Scanner sc=new Scanner(System.in);
23             BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(sk.getOutputStream()));
24             BufferedReader br=new BufferedReader(new InputStreamReader(sk.getInputStream()));
25             while(true){
26                 System.out.println("请输入文字：");
27                 String info=sc.next();
28                 if("bye".equals(info)){
29                     break;
30                 }else{
31                     bw.write(info+"
");
32                     bw.flush();
33                     System.out.println(br.readLine());
34                 }
35             }
36             bw.close();
37             br.close();
38         } catch (IOException e) {
39             e.printStackTrace();
40         }
41         
42     }
43 }