第七章作业

import com.alibaba.fastjson.JSON;
import com.google.common.collect.Lists;
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 org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.stream.Collectors;

public class StressTest {
    public static void main(String[] args) {
        //并发10，请求1000次
        pressTest("http://www.baidu.com", 10, 1000);
        //并发100，请求1000次
        pressTest("http://www.baidu.com", 100, 1000);
    }

    private static void pressTest(String uri, int concurrentCount, int reqCount) {
        ExecutorService executor = Executors.newFixedThreadPool(concurrentCount);
        List<Long> responseTimeStats = Collections.synchronizedList(Lists.newLinkedList());
        int i = 0;
        PoolingHttpClientConnectionManager connManager = new PoolingHttpClientConnectionManager();
        connManager.setMaxTotal(concurrentCount);
        connManager.setDefaultMaxPerRoute(concurrentCount);
        CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(connManager).build();
        CountDownLatch latch = new CountDownLatch(reqCount);
        while (i++ < reqCount) {
            executor.submit(() -> {
                HttpGet method = new HttpGet(uri);
                CloseableHttpResponse httpResponse = null;
                try {
                    long start = System.currentTimeMillis();
                    httpResponse = httpClient.execute(method);
                    long responseTime = System.currentTimeMillis() - start;
                    responseTimeStats.add(responseTime);
                } catch (IOException e) {
                    e.printStackTrace();
                } finally {
                    if (httpResponse != null) {
                        try {
                            EntityUtils.consume(httpResponse.getEntity());
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
                latch.countDown();
            });
        }
        try {
            latch.await();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        int responseCount = responseTimeStats.size();
        long average = responseTimeStats.stream().mapToLong(Long::longValue).sum() / responseCount;
        List<Long> reversedSortedResponseTimeStats = responseTimeStats.stream().sorted(Comparator.comparing(Long::longValue).reversed()).collect(Collectors.toList());
        List<Long> responseTimeStats95 = reversedSortedResponseTimeStats.subList((int) (responseCount * 0.05), responseCount - 1);
        System.out.println("并发数:" + concurrentCount + ",请求次数:" + reqCount + ",平均响应时间:" + average + ",95%响应时间:" + responseTimeStats95.get(0));
//        System.out.println("响应时间明细:" + JSON.toJSONString(reversedSortedResponseTimeStats));
    }
}