perftest.url=https://www.baidu.com
perftest.total_request=100
perftest.concurrent_count=10
perftest.interval_per_request=100

@Slf4j
public class PerfTestExecutor {
  private final OkHttpClient okHttpClient;
  private final PerfTestConf perfTestConf;
  private final Request perfTestRequest;
  private final int loopCount;
  private final Map<String, List<Long>> requestTimesMap = new ConcurrentHashMap<>();
  private final CountDownLatch startSignal;
  private final CountDownLatch doneSignal;
  public PerfTestExecutor(OkHttpClient okHttpClient, PerfTestConf perfTestConf) {
    assert perfTestConf.getConcurrentCount() > 0;
    assert perfTestConf.getTotalRequest() >= perfTestConf.getConcurrentCount();
    this.okHttpClient = okHttpClient;
    this.perfTestConf = perfTestConf;
    perfTestRequest = new Request.Builder().url(perfTestConf.getUrl()).build();
    loopCount = (int) Math.ceil((double) perfTestConf.getTotalRequest() / perfTestConf.getConcurrentCount());
    System.out.println("loopCount: " + loopCount);
    this.startSignal = new CountDownLatch(1);
    this.doneSignal = new CountDownLatch(perfTestConf.getConcurrentCount());
    init();
  }
  private void init() {
    for (int j = 0; j < perfTestConf.getConcurrentCount(); j++) {
      final String threadName = "Thread-" + j;
      new Thread(() -> {
        try {
          startSignal.await();
        } catch (InterruptedException e) {
          e.printStackTrace();
        }
        long requestTime;
        for (int i = 0; i < loopCount; i++) {
          long startTimeInMilli = System.currentTimeMillis();
          try (Response response = okHttpClient.newCall(perfTestRequest).execute()) {
            log.info("Response " + i + " from " + perfTestConf.getUrl());
            requestTime = System.currentTimeMillis() - startTimeInMilli;
            requestTimesMap.computeIfAbsent(threadName, k -> new ArrayList<>()).add(requestTime);
            if (perfTestConf.getIntervalPerRequest() > 0 && requestTime < perfTestConf.getIntervalPerRequest()) {
              Thread.sleep(perfTestConf.getIntervalPerRequest() - requestTime);
            }
          } catch (InterruptedException | IOException e) {
            log.warn("Exception", e);
          }
        }
        doneSignal.countDown();
      }).start();
    }
  }
  public void start() {
    startSignal.countDown();
  }
  public void await() throws InterruptedException {
    doneSignal.await();
  }
  public List<Long> getRequestTimeList() {
    return requestTimesMap.values().stream().flatMap(Collection::stream).sorted().collect(Collectors.toList());
  }
}

@SpringBootApplication
public class PerfTestApplication implements ApplicationRunner {
  @Autowired
  private OkHttpClient okHttpClient;
  @Autowired
  private PerfTestConf perfTestConf;
  public static void main(String[] args) {
    SpringApplication.run(PerfTestApplication.class, args);
  }
  @Override
  public void run(ApplicationArguments args) throws Exception {
    System.out.println(perfTestConf);
    PerfTestExecutor testExecutor = new PerfTestExecutor(okHttpClient, perfTestConf);
    testExecutor.start();
    testExecutor.await();
    generateStatistics(testExecutor.getRequestTimeList());
  }
  public void generateStatistics(List<Long> longList) {
    // longList.forEach(System.out::println);
    double average = longList.stream().mapToLong(l -> l).average().getAsDouble();
    int p95Count = (int) Math.floor(perfTestConf.getTotalRequest() * 0.95);
    long p95 = longList.stream().mapToLong(l -> l).skip(p95Count - 1).findFirst().getAsLong();
    System.out.println("Average: " + average);
    System.out.println("95%: " + p95);
  }
}

Average: 35.41
95%: 206
// 下面是所有的 100 个请求时间
10
11
11
11
11
11
11
11
11
11
11
11
12
12
12
12
12
12
12
12
12
12
12
12
12
12
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
14
14
14
14
14
14
14
14
14
14
14
14
14
15
15
15
15
15
15
15
15
15
16
17
17
17
17
17
17
17
18
18
18
18
18
18
18
22
36
42
56
57
62
69
206
206
206
206
206
206
206
206
206
206