Java线程池如何实现精准控制每秒API请求

    <!-- Apache HttpClient -->
    <dependency>
        <groupId>org.apache.httpcomponents.client5</groupId>
        <artifactId>httpclient5</artifactId>
        <version>5.2</version>
    </dependency>

import org.apache.hc.client5.http.classic.methods.HttpGet;
import org.apache.hc.client5.http.classic.methods.HttpUriRequestBase;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.core5.http.ParseException;
import org.apache.hc.core5.http.io.entity.EntityUtils;

import java.io.IOException;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicInteger;

public class ApiRequestScheduler {

    // 定义线程池，用于并发发送API请求
    private final ExecutorService requestExecutor;

    // 定义调度线程池，用于定时调度请求任务
    private final ScheduledExecutorService scheduler;

    // 记录已发送的请求数量
    private final AtomicInteger requestCounter;

    // 每秒发送的请求数量
    private final int requestsPerSecond;

    // Apache HttpClient 实例
    private final CloseableHttpClient httpClient;

    // API 请求的目标URL
    private final String apiUrl;

    // 构造函数，初始化线程池和调度器
    public ApiRequestScheduler(int requestsPerSecond, String apiUrl) {
        this.requestsPerSecond = requestsPerSecond;
        this.requestExecutor = Executors.newFixedThreadPool(requestsPerSecond);
        this.scheduler = Executors.newScheduledThreadPool(1);
        this.requestCounter = new AtomicInteger(0);
        this.httpClient = HttpClients.createDefault();
        this.apiUrl = apiUrl;
    }

    // 开始调度API请求任务
    public void start() {
        // 每秒调度任务，按照每秒发送的请求数量来执行
        scheduler.scheduleAtFixedRate(() -> {
            for (int i = 0; i < requestsPerSecond; i++) {
                requestExecutor.submit(this::sendApiRequest);
            }
        }, 0, 1, TimeUnit.SECONDS);
    }

    // 停止调度和关闭线程池及HttpClient
    public void stop() {
        scheduler.shutdown();
        requestExecutor.shutdown();
        try {
            if (!scheduler.awaitTermination(1, TimeUnit.SECONDS)) {
                scheduler.shutdownNow();
            }
            if (!requestExecutor.awaitTermination(1, TimeUnit.SECONDS)) {
                requestExecutor.shutdownNow();
            }
            httpClient.close();
        } catch (InterruptedException | IOException e) {
            scheduler.shutdownNow();
            requestExecutor.shutdownNow();
            try {
                httpClient.close();
            } catch (IOException ioException) {
                ioException.printStackTrace();
            }
        }
    }

    // 使用Apache HttpClient发送API请求
    private void sendApiRequest() {
        int requestId = requestCounter.incrementAndGet();
        HttpUriRequestBase request = new HttpGet(apiUrl);
        System.out.println("Sending API request #" + requestId);

        try (CloseableHttpResponse response = httpClient.execute(request)) {
            String responseBody = EntityUtils.toString(response.getEntity());
            System.out.println("Request #" + requestId + " completed with status: " + response.getCode() +
                    ", response: " + responseBody);
        } catch (IOException | ParseException e) {
            System.err.println("Request #" + requestId + " failed: " + e.getMessage());
        }
    }

    public static void main(String[] args) {
        // 每秒发送5个API请求，目标URL为http://example.com/api
        ApiRequestScheduler scheduler = new ApiRequestScheduler(5, "http://www.dzy.com/api");

        // 启动调度器
        scheduler.start();

        // 运行10秒后停止调度器
        try {
            Thread.sleep(10000);
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }

        // 停止调度器
        scheduler.stop();
    }
}