Week7 作业

public class PerformanceTest {
    private static OkHttpClient client = new OkHttpClient();
    public static void main(String[] args) throws InterruptedException {
//        String url = "https://www.baidu.com"; // avg 3.6, 95% 32
//        String url = "https://u.geekbang.org/"; // avg 5.99 95% 56
//        String url = "https://www.google.com/"; // avg 29.42 95% 255
        String url = "https://www.taobao.com/"; // avg 43 95% 556
        int concurrent = 10;
        int count = 100;
        CountDownLatch countDownLatch = new CountDownLatch(concurrent);
        CopyOnWriteArrayList<Long> result = new CopyOnWriteArrayList<>();
        for (int i = 0; i < concurrent; i++) {
            new Thread(() -> {
                List<Long> statistics = new ArrayList<>();
                Supplier<Boolean> test = () -> testUrl(url);
                for (int j = 0; j < count; j++) {
                    statistics.add(recordTest(test));
                }
                result.addAll(statistics);
                countDownLatch.countDown();
            }).start();
        }
        countDownLatch.await();
        long sum = 0;
        long time95 = -1;
        int time95index = (int) (result.size() * 0.95);
        for (int i = 0; i < result.size(); i++) {
            sum += result.get(i);
            if (i == time95index) {
                time95 = result.get(i);
            }
        }
        System.out.println("avg: " + (0.1 * sum / result.size()));
        System.out.println("95%: " + time95);
    }
    private static Long recordTest(Supplier<Boolean> test) {
        long start = System.currentTimeMillis();
        Boolean isSuccess = test.get();
        long end = System.currentTimeMillis();
        return end - start;
    }
    private static boolean testUrl(String url) {
        Request request = new Request.Builder().get().url(url).build();
        try (Response response = client.newCall(request).execute()) {
//            System.out.println(response);
            return true;
        } catch (IOException e) {
            e.printStackTrace();
            return false;
        }
    }
}