使用ScheduledExecutorService计划每月任务

import java.util.Calendar;
import java.util.Date;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class MonthlyTaskScheduler {
    private ScheduledExecutorService scheduler;

    public MonthlyTaskScheduler() {
        scheduler = Executors.newScheduledThreadPool(1);
    }

    public void scheduleMonthlyTask(Runnable task, int dayOfMonth, int hour, int minute) {
        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.DAY_OF_MONTH, dayOfMonth);
        calendar.set(Calendar.HOUR_OF_DAY, hour);
        calendar.set(Calendar.MINUTE, minute);
        calendar.set(Calendar.SECOND, 0);
        Date scheduledTime = calendar.getTime();

        Date currentTime = new Date();
        if (scheduledTime.before(currentTime)) {
            // 如果计划时间早于当前时间，则将计划时间设置为下个月的同一天
            calendar.add(Calendar.MONTH, 1);
            scheduledTime = calendar.getTime();
        }

        long initialDelay = scheduledTime.getTime() - currentTime.getTime();
        scheduler.scheduleAtFixedRate(task, initialDelay, 30, TimeUnit.DAYS);
    }

    public void shutdown() {
        scheduler.shutdown();
    }

    public static void main(String[] args) {
        MonthlyTaskScheduler taskScheduler = new MonthlyTaskScheduler();
        Runnable task = new Runnable() {
            @Override
            public void run() {
                // 执行每月任务的逻辑
                System.out.println("执行每月任务");
            }
        };
        taskScheduler.scheduleMonthlyTask(task, 1, 0, 0); // 每月1号的0点0分执行任务
    }
}