java代码实现 构建下载线程池及队列 ，接收用户请求存mysql同时放入队列

好的，下面是Java代码实现：

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.LinkedBlockingQueue;

public class DownloadThreadPool {
    private ExecutorService executorService;
    private LinkedBlockingQueue<DownloadTask> downloadQueue;

    public DownloadThreadPool(int threadPoolSize) {
        executorService = Executors.newFixedThreadPool(threadPoolSize);
        downloadQueue = new LinkedBlockingQueue<>();
    }

    public void addDownloadTask(DownloadTask task) {
        // 存储到 MySQL 数据库
        saveToMysql(task);
        // 将任务添加到队列中
        downloadQueue.offer(task);
        // 提交任务到线程池执行
        executorService.submit(new DownloadRunnable(downloadQueue));
    }

    private void saveToMysql(DownloadTask task) {
        // 存储到 MySQL 数据库的代码
        // ...
    }
}

class DownloadTask {
    private String url;
    private String filename;

    public DownloadTask(String url, String filename) {
        this.url = url;
        this.filename = filename;
    }

    public String getUrl() {
        return url;
    }

    public String getFilename() {
        return filename;
    }
}

class DownloadRunnable implements Runnable {
    private LinkedBlockingQueue<DownloadTask> downloadQueue;

    public DownloadRunnable(LinkedBlockingQueue<DownloadTask> downloadQueue) {
        this.downloadQueue = downloadQueue;
    }

    @Override
    public void run() {
        while (!Thread.currentThread().isInterrupted()) {
            try {
                DownloadTask task = downloadQueue.take();
                // 下载任务的代码
                // ...
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
        }
    }
}

以上代码实现了一个下载线程池及队列，其中`DownloadTask`表示下载任务，包含要下载的URL和文件名；`DownloadRunnable`表示下载线程，从队列中取出任务并执行下载操作；`DownloadThreadPool`表示下载线程池，负责接收用户请求，存储到MySQL数据库，将任务添加到队列中并提交到线程池执行。