模拟分店向总店上传下载文件的压力测试

[zhaozhi815]

服务器：FTP

目的：利用java多线程机制，在同一时间从服务器段下载不同文件的压力测试。

欢迎各位提供思路。主要是这个架子怎么搭上去。

[daimojingdeyu]

模拟程序应该不复杂，不需要过多的设计。

可将连接、下载相关的代码抽取出来，指定获取文件名的操作在各个线程中设置。
各个下载线程的可先在一个CountDownLatch的变量上等待，等时间一到，由主线程
将此CountDownLatch放开，则可基本上保证下载线程同一时间开始启动

[宁静-夏天]

感觉没有设计的必要，线程之间没有通信的必要，

写好一个线程下载文件。

那么就起多个这样的线程就好了。

如果是多线程同时下载，还有些线程之间通信存在，稍微要难点。

[zhaozhi815]

package com.suzhou.jackey;
import java.io.BufferedInputStream;
import java.io.RandomAccessFile;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.concurrent.CountDownLatch;

public class FileDownloadTest2 {
    private static final int THREAD_COUNT = 10;
    private CountDownLatch latch = new CountDownLatch(THREAD_COUNT);
    private long completeLength = 0;
    private long fileLength;
   
    //进行下载的线程
    class DownloadThread extends Thread {
        private URL url;
        private RandomAccessFile file;
        private long from;
        private long end;

        /**
         * @param url 下载的URL
         * @param file 下载完成之后存储的文件
         * @param from 当前线程对应文件的起始位置
         * @param end 当前线程对应文件的结束位置
         */
        DownloadThread(URL url, RandomAccessFile file, long from, long end) {
            this.url = url;
            this.file = file;
            this.from = from;
            this.end = end;
            
        }

        public void run() {
            try {
            	
            	Long file_request_time = System.currentTimeMillis();
            	
                long pos = from;
                byte[] buf = new byte[1024];

                HttpURLConnection cn = (HttpURLConnection) url.openConnection();
               
                //因为有些网站根据它判断是否是盗链接
                cn.setRequestProperty("Referer", "http://172.28.131.208:8080");
               
                //设置请求的起始和结束位置。
                cn.setRequestProperty("Range", "bytes=" + from + "-" + end);
               
                //如果请求错误，重试。
                if(cn.getResponseCode() != 200 && cn.getResponseCode() != 206){
                    System.out.println("Responce Code: " + cn.getResponseCode());
                    run();
                    return;
                }
                
                
                
                BufferedInputStream bis = new BufferedInputStream(cn.getInputStream());
                int len;
                while ((len = bis.read(buf)) > 0) {
                    synchronized (file) {
                        file.seek(pos);
                        file.write(buf, 0, len);
                    }
                    pos += len;
                    completeLength += len;
                    if(completeLength * 100 / fileLength % 10 == 0){
                    	//System.out.println(Thread.currentThread().getName() + ":" + completeLength * 100 / fileLength + "%");
                    }
                    
                }
                cn.disconnect();
                
                
                
                long transfer_time = System.currentTimeMillis();
				
                
                long downLoadTime = transfer_time - file_request_time;
				System.out
				.println(Thread.currentThread().getName() + "--------StartTime--------------- :"
						+ milltoString2(file_request_time));
				
				System.out
				.println(Thread.currentThread().getName() + "--------End Time--------------- :"
						+ milltoString2(transfer_time));
				
				System.out
				.println(Thread.currentThread().getName() + "--------DownLoad Time----------------- :"
						+ milltoString(downLoadTime));

            } catch (Exception e) {
                e.printStackTrace();
            }
            latch.countDown();
        }
    }

	public static String milltoString(long millseconds) { // convert millionseconds
		// into string
		DateFormat formatter = new SimpleDateFormat("mm分ss.SSS秒");
		Calendar calendar = Calendar.getInstance();
		calendar.setTimeInMillis(millseconds); // connection sum time ;
		return formatter.format(calendar.getTime());
	}
	
	public static String milltoString2(long millseconds) { // convert millionseconds
		// into string
		DateFormat formatter = new SimpleDateFormat("HH时mm分ss.SSS秒");
		Calendar calendar = Calendar.getInstance();
		calendar.setTimeInMillis(millseconds); // connection sum time ;
		return formatter.format(calendar.getTime());
	}
	
    public void download(String address) throws Exception {
        URL url = new URL(address);
        URLConnection cn = url.openConnection();
        cn.setRequestProperty("Referer", "http://172.28.131.208:8080");
        fileLength = cn.getContentLength();
       
        //RandomAccessFile file = new RandomAccessFile("Example2.rar", "rw");
       
        System.out.println("file size:" + (float)fileLength/1024/1024 + "M");
        //计算每个线程请求的起始位置和结束位置。
        long pos = 0;
        for (int i = 0; i < THREAD_COUNT; i++) {
            RandomAccessFile file = new RandomAccessFile("Example"+ i + ".rar", "rw");
            new DownloadThread(url, file, pos, fileLength).start();
        }
        latch.await();
    }

    public static void main(String[] args) throws Exception {
        long time = System.currentTimeMillis();
        new FileDownloadTest2()
                .download("http://172.28.131.208:8080/Example.rar");
        System.out.println("共用时："+milltoString(System.currentTimeMillis() - time));
    }

}

[zhaozhi815]

结合网上的例子，写了一个压力测试的例子，有改进的地方吗。