第七周作业

import org.apache.http.HttpStatus;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * Created by ANDY on 2020/7/17.
 *
 * 用你熟悉的编程语言写一个 web 性能压测工具，
 * 输入参数：URL，请求总次数，并发数。
 * 输出参数：平均响应时间，95% 响应时间。
 * 用这个测试工具以 10 并发、100 次请求压测 www.baidu.com。
 */
public class Test {


    public static void main(String[] args){
        new Test().test("http://www.baidu.com",2,5);
        System.exit(0);
    }


    public void test(final String url,int totalCount,int bfCount){
        ExecutorService threadPools = Executors.newFixedThreadPool(bfCount);
        final CountDownLatch countD = new CountDownLatch(totalCount);

        long startTime = System.currentTimeMillis();
        long endTime = 0l;
        final List<Long> times = new ArrayList<Long>(totalCount);

        for(int i = 0 ; i < totalCount ; i++){
            threadPools.execute(new Runnable() {

                public void run() {
                    try{
                        times.add(sendRequest(url));
//                        System.out.println(Thread.currentThread().getName());
                    }catch (Exception e){

                    }finally {
                        countD.countDown();
                    }

                }
            });
        }
        try{
            countD.await();
        }catch (Exception e){

        }finally {
            endTime = System.currentTimeMillis();
            System.out.println("it's ok !");
        }
        Collections.sort(times);
//        95%响应时间
        int no_95 =totalCount*95/100;
        long i = 1l;
        long tmp= 0l;
        for(long no:times){
            tmp+= no;
            //简单判定95%响应时间
            if(i/totalCount == no_95 || i== no_95){
                System.out.println("95%响应时间为："+no + "ms");
            }
            i++;
        }
        System.out.println("平均响应时间："+tmp/totalCount  +"ms");
    }
    /**
     *
     * @param url
     * @return 请求目标地址，并返回请求耗时time
     */
    public long sendRequest(String url){
    long startTime = System.currentTimeMillis();
    long endTime = 0l;
     CloseableHttpClient client = HttpClients.createDefault();
     // 发送get请求
     HttpGet request = new HttpGet(url);

        CloseableHttpResponse response = null;
        try {
            response = client.execute(request);
            // 请求发送成功，并得到响应
            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK)
            {
                //可以统计请求成功次数
            }
            else
            {
                System.out.println("get请求提交失败:" + url);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            request.releaseConnection();
            endTime = System.currentTimeMillis();
        }
        System.out.println("cost time" + (endTime-startTime));
        return endTime-startTime;
        }

}