网络编程+IO+多线程

随机产生结果（刚刚学完网络编程顺手做了一个小程序）

import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
import java.io.PrintStream;
class MyThread implements Runnable{
private Socket client;
public MyThread(Socket client){
this.client=client;
}
public void run(){
try{
Scanner in = new Scanner(this.client.getInputStream());
in.useDelimiter("\n");
PrintStream out = new PrintStream(this.client.getOutputStream());
boolean flag = true;
while(flag){
if(in.hasNext()){
String data = in.next().trim();
if(“exit”.equalsIgnoreCase(data)){
flag = false;
out.println(“程序结束，再见”);
}else{
out.println(“ECHO:”+data);
}
}
}
this.client.close();
}catch(Exception e){
e.printStackTrace();
}
}
}
public class EchoServer{
public static void main(String[] args) throws Exception {
ServerSocket server = new ServerSocket(9999);
System.out.println(“服务端开启…”);
boolean flag =true;
while(flag){
Socket client = server.accept();
new Thread(new MyThread(client)).start();
}
server.close();
}
}
import java.net.ServerSocket;
import java.net.Socket;
import java.io.PrintStream;
import java.util.Random;
public class EchoClient{
public static void main(String[] args) throws Exception{
Socket client = new Socket(“localhost”,9999);
Scanner in = new Scanner (client.getInputStream());
in.useDelimiter("\n");
PrintStream out = new PrintStream(client.getOutputStream());
Random r=new Random();
int num=r.nextInt(5);
switch(num){
case 1:
System.out.println(“麻辣烫”);
break;
case 2:
System.out.println(“披萨”);
break;
case 3:
System.out.println(“奶茶”);
break;
case 4:
System.out.println(“火锅”);
break;
case 5:
System.out.println(“冰激凌”);
break;
default:
System.out.println(“error”);
break;
}
client.close();
}
}