题目

想要服务器不停止，能接收很多客户上传的图片？我们知道是使用循环加多线程的方案来解决，但是如果频繁的创建和销毁线程，是非常浪费系统资源的，那应该怎么办呢？

解决方案

采用线程池，来管理线程

代码实战

客户端代码

package com.heima;import java.io.*;
import java.net.Socket;public class Client {public static void main(String[] args) throws IOException {Socket socket = new Socket("127.0.0.1",10000);//读取本地文件中的数据，并写到服务器中BufferedInputStream bis = new BufferedInputStream(new FileInputStream("G:\\wjkwk\\clientdir\\123.jpg"));BufferedOutputStream bos = new BufferedOutputStream(socket.getOutputStream());byte[] bytes = new byte[1024];int len;while ((len = bis.read(bytes)) != -1){bos.write(bytes,0,len);}//往服务器写结束标记socket.shutdownOutput();//接收服务器返回的数据BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));String line = br.readLine();System.out.println(line);socket.close();}
}

服务端代码

package com.heima;import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;public class Server {public static void main(String[] args) throws IOException {ThreadPoolExecutor pool = new ThreadPoolExecutor(3,16,60,TimeUnit.SECONDS,new ArrayBlockingQueue<>(2),//Executors.defaultThreadFactory(),//线程工厂，让线程池如何创建线程对象new ThreadPoolExecutor.AbortPolicy()//阻塞队列);ServerSocket serverSocket = new ServerSocket(10000);while (true){//等待客户端来连接Socket socket = serverSocket.accept();//开启一个线程//一个用户就对应服务端的一条线程
//            new Thread(new MyRunnable(socket)).start();//使用线程池pool.submit(new MyRunnable(socket));}}
}

package com.heima;import java.io.*;
import java.net.Socket;
import java.util.UUID;public class MyRunnable implements Runnable {Socket socket;public MyRunnable(Socket socket){this.socket = socket;}@Overridepublic void run() {try {//读取客户端上传的文件并保存到本地BufferedInputStream bis = new BufferedInputStream(socket.getInputStream());String name = UUID.randomUUID().toString().replace("-", "");BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream("G:\\wjkwk\\serverdir\\"+name+".jpg"));int len;byte[] bytes = new byte[1024];while ((len = bis.read(bytes)) != -1){bos.write(bytes,0,len);}//回写数据BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));bw.write("上传成功");bw.newLine();bw.flush();} catch (IOException e) {e.printStackTrace();} finally {//释放资源try {socket.close();} catch (IOException e) {e.printStackTrace();}}}
}