Socket网络编程练习题五：客户端多用户上传文件（多线程版）并使用线程池管理线程

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();
    }
}

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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));
        }
    }
}

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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;
    }
    @Override
    public 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();
            }
        }
    }
}

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