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"
"换行符
            System.out.println(info);
            if("".equals(info)||"bye".equals(info)){
                break;
            }else{
                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
                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+"
");
                    bw.flush();
                    System.out.println(br.readLine());
                }
            }
            bw.close();
            br.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        
    }
}