作业 -07- 性能优化

package com.example.demo;
import org.apache.commons.lang3.StringUtils;
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.Arrays;
import java.util.concurrent.CountDownLatch;
/**
 * 压力测试
 */
public class StressTest {
    public static void main(String[] arg) {
        int requestCount = 100;//请求次数
        int parallelCount = 10;//并发次数
        long[] responseTimes = new long[requestCount];
        for (int i = 0; i < requestCount; i++) {
            responseTimes[i] = parallelTesk(parallelCount, new Runnable() {
                @Override
                public void run() {
                    CloseableHttpClient httpClient = HttpClients.createDefault();
                    HttpGet httpGet = new HttpGet("http://www.baidu.com");
                    CloseableHttpResponse response = null;
                    try {
                        response = httpClient.execute(httpGet);
                        if (response.getStatusLine().getStatusCode() == 200) {
                        }
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            });
        }
        //排序
        Arrays.sort(responseTimes);
        long sum = 0;
        for (long time : responseTimes) {
            sum += time;
        }
        System.out.println("所有时间："+ StringUtils.join(responseTimes,','));
        System.out.println("平均响应时间：" + sum / responseTimes.length);
        System.out.println("95%响应时间：" + responseTimes[94]);
    }
    /**
     * 高并发测试
     *
     * @param threadNum
     * @param task
     */
    public static long parallelTesk(int threadNum, Runnable task) {
        // 1. 定义闭锁来拦截线程
        final CountDownLatch startGate = new CountDownLatch(1);
        final CountDownLatch endGate = new CountDownLatch(threadNum);
        // 2. 创建指定数量的线程
        for (int i = 0; i < threadNum; i++) {
            Thread t = new Thread(() -> {
                try {
                    startGate.await();
                    try {
                        task.run();
                    } finally {
                        endGate.countDown();
                    }
                } catch (InterruptedException e) {
                }
            });
            t.start();
        }
        // 3. 线程统一放行，并记录时间！
        long start = System.currentTimeMillis();
        startGate.countDown();
        try {
            endGate.await();
        } catch (InterruptedException e) {
        }
        long end = System.currentTimeMillis();
        return end - start;
    }
}