springboot 指定某个时间点执行定时任务

用到的组件：

• springboot的实现CommandLineRunner接口或者使用@PostContruct注解
• Timer、TimerTask
• LocalDateTime

具体实现：

• 一、实现CommandLineRunner

import org.springframework.boot.CommandLineRunner;
import org.springframework.stereotype.Component;

[@Component](https://my.oschina.net/u/3907912)
public class MyCommandLineRunner implements CommandLineRunner {

    [@Override](https://my.oschina.net/u/1162528)
    public void run(String... var1) throws Exception{
        System.out.println("This will be execute when the project was started!");
        new DemoController().demo();
    }
}

• DemoController

import java.time.LocalDateTime;
import java.time.temporal.ChronoField;
import java.util.Calendar;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;

/**
 * [@Author](https://my.oschina.net/arthor) he qing yu
 * [@Date](https://my.oschina.net/u/2504391) 2021/4/19 10:33
 * @Version 1.0
 */
public class DemoController {
    // 指定触发的时间
    LocalDateTime localDateTime = LocalDateTime.of(2021, 04, 19, 11, 00, 01);
    public void demo(){

        /**
         * localDateTime.get(ChronoField.YEAR); 获取年
         * localDateTime.get(ChronoField.MONTH_OF_YEAR); 获取月
         * localDateTime.get(ChronoField.DAY_OF_MONTH);  获取日
         * localDateTime.get(ChronoField.HOUR_OF_DAY); 获取小时
         * localDateTime.get(ChronoField.MINUTE_OF_HOUR); 获取分
         * localDateTime.get(ChronoField.SECOND_OF_MINUTE); 获取秒
         */

        System.out.println(
                localDateTime.get(ChronoField.YEAR)+":"
                +localDateTime.get(ChronoField.MONTH_OF_YEAR)+":"
                +localDateTime.get(ChronoField.DAY_OF_MONTH)+":"
                +localDateTime.get(ChronoField.HOUR_OF_DAY)+":"
                +localDateTime.get(ChronoField.MINUTE_OF_HOUR)+":"
                +localDateTime.get(ChronoField.SECOND_OF_MINUTE)
        );

        Calendar calendar = Calendar.getInstance();

        /**
         * 指定触发的时间
         * */
        calendar.set(Calendar.YEAR, localDateTime.get(ChronoField.YEAR)); // 设置年份
        calendar.set(Calendar.DAY_OF_MONTH, localDateTime.get(ChronoField.DAY_OF_MONTH));//设置日期
        calendar.set(Calendar.MONTH, localDateTime.get(ChronoField.MONTH_OF_YEAR)-1);//设置日期为月份   这里3表示4月份    4就表示5月份
        calendar.set(Calendar.HOUR_OF_DAY, localDateTime.get(ChronoField.HOUR_OF_DAY)); //设置触发时
        calendar.set(Calendar.MINUTE, localDateTime.get(ChronoField.MINUTE_OF_HOUR)); //设置触发分
        calendar.set(Calendar.SECOND, localDateTime.get(ChronoField.SECOND_OF_MINUTE)); //设置触发秒

        Date time = calendar.getTime();
        Timer timer = new Timer();
        timer.schedule(new RemindTask(), time);
    }

    class RemindTask extends TimerTask {
        public void run() {
            System.out.println("localDateTime:"+localDateTime);
        }
    }
}

上面参考： https://blog.csdn.net/xihulu_a/article/details/115860647

二、使用@PostContruct：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;
import java.time.LocalDateTime;
import java.time.temporal.ChronoField;
import java.util.*;

@Component
public class TermUpgradeService {

    List<LocalDateTime> localDateTimeList = new ArrayList<>();

    {
        // 指定触发的时间
        LocalDateTime localDateTime = LocalDateTime.of(2022, 07, 18, 18, 40, 30);
        localDateTimeList.add(localDateTime);
    }

    @PostConstruct
    public void init(){
        new DemoController().demo();
    }
}