一、業(yè)務(wù)場景

先說業(yè)務(wù)場景，根據(jù)用戶輸入的cron表達(dá)式進(jìn)行定時(shí)調(diào)度，舉個(gè)例子：如圖

根據(jù)用戶輸入的參數(shù)，生成表達(dá)式，然后定時(shí)去執(zhí)行相應(yīng)的業(yè)務(wù)邏輯。

二、Controller層（不是重點(diǎn)）

domain類

复制@TableName("sys_schedule")
@Data
public class Schedule {

    private static final long serialVersionUID = 1L;

    /**
     * 主鍵ID
     */
    @TableId(value = "id", type = IdType.AUTO)
    private Long id;

    /**
     * 類型: 時(shí)間， 周， 日
     */
    @TableField("type")
    private Integer type;

    /**
     * time 時(shí)間
     */
    @TableField("day_time")
    private String dayTime;

    /**
     * time 周
     */
    @TableField("weekday")
    private String weekday;

    /**
     * time 日
     */
    @TableField("monthday")
    private String monthday;

    /**
     * 選中狀態(tài)
     */
    @TableField("status")
    private Integer status;

    @TableField("cron")
    private String cron;

    @Override
    public String toString() {
        return "Schedule{" +
                "id=" + id +
                ", type=" + type +
                ", dayTime='" + dayTime + '\\'' +
                ", weekday='" + weekday + '\\'' +
                ", monthday='" + monthday + '\\'' +
                ", status=" + status +
                ", cron='" + cron + '\\'' +
                '}';
    }
}

controller方法

复制@Autowired
    private ScheduleService scheduleService;
 
  @PutMapping("/editItem")
    @ResponseBody
    public ResponseData editItem(Schedule schedule) {
        //ResponseData自己封裝的響應(yīng)結(jié)果
        //param是你前端傳的，包含你的數(shù)據(jù)，如cron表達(dá)式
        this.scheduleService.update(schedule);
        return ResponseData.success();
    }

三、Service層

接口層

复制public interface ScheduleService {

    /**
     * 更新
     * @Date 2020-12-25
     */
    void update(Schedule param);

    /**
     * 業(yè)務(wù)處理
     * @Date 2020-12-25
     */
    void work();

}

實(shí)現(xiàn)層

复制@Service
public class ScheduleServiceImpl implements ScheduleService {
    
 @Override
    public void update(Schedule param) {
  //這里簡化了我自己的業(yè)務(wù)邏輯代碼，根據(jù)公司自己需要來寫即可
        //業(yè)務(wù)邏輯代碼
        
        //思路就是：更新數(shù)據(jù)庫的cron，類型等值，然后交給下面的定時(shí)工具類走定時(shí)方法
        this.scheduleMapper.updateById(param);
        String cron = param.getCron();
        //this就是你的業(yè)務(wù)執(zhí)行service, 這里就是scheduleService
        ScheduleUtil.reset(new ScheduleTask(param.getId().toString(), this, null), cron);
    }
    
    @Override
    public void work() {
        //抓取數(shù)據(jù)的代碼
        System.out.println("業(yè)務(wù)代碼執(zhí)行。。。");
    }

    
}

四、定時(shí)工具類

复制import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;
import org.springframework.scheduling.support.CronTrigger;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ScheduledFuture;

public class ScheduleUtil {

    private static ThreadPoolTaskScheduler threadPoolTaskScheduler = new    ThreadPoolTaskScheduler();
    private static Map<String, ScheduledFuture?> scheduledFutureMap = new HashMap<>();

    static {
        threadPoolTaskScheduler.initialize();
        System.out.println("定時(shí)任務(wù)線程池啟動(dòng)");
    }

    /**
     * 啟動(dòng)
     *
     * @param scheduleTask 定時(shí)任務(wù)
     * @param corn         執(zhí)行時(shí)間表達(dá)式
     */
    public static boolean start(ScheduleTask scheduleTask, String corn) {
        System.out.println("啟動(dòng)定時(shí)任務(wù)線程 taskId " + scheduleTask.getId());
        ScheduledFuture? scheduledFuture = threadPoolTaskScheduler
                .schedule(scheduleTask, new CronTrigger(corn));
        scheduledFutureMap.put(scheduleTask.getId(), scheduledFuture);
        return true;
    }

    /**
     * 取消
     *
     * @param scheduleTask 定時(shí)任務(wù)
     */
    public static boolean cancel(ScheduleTask scheduleTask) {
        System.out.println("關(guān)閉定時(shí)任務(wù)線程 taskId " + scheduleTask.getId());
        ScheduledFuture? scheduledFuture =       scheduledFutureMap.get(scheduleTask.getId());
        if (scheduledFuture != null && !scheduledFuture.isCancelled()) {
            scheduledFuture.cancel(false);
        }
        scheduledFutureMap.remove(scheduleTask.getId());
        return true;
    }

    /**
     * 修改
     *
     * @param scheduleTask 定時(shí)任務(wù)
     * @param corn         執(zhí)行時(shí)間表達(dá)式
     */
    public static boolean reset(ScheduleTask scheduleTask, String corn) {
        //先取消定時(shí)任務(wù)
        cancel(scheduleTask);
        //然后啟動(dòng)新的定時(shí)任務(wù)
        start(scheduleTask, corn);
        return true;
    }
}

五、工作線程

复制public class ScheduleTask implements Runnable {

    private static final int TIMEOUT = 30000;

    private String id;
    private ScheduleService service;

    public String getId() {
        return id;
    }

    /**
     * @param id      任務(wù)ID
     * @param service 業(yè)務(wù)類
     * @param keyword 關(guān)鍵字參數(shù)
     */
    public ScheduleTask(String id, ScheduleService service) {
        this.id = id;
        this.service = service;
    }

    @Override
    public void run() {
        //你自己的業(yè)務(wù)邏輯
        service.work();
    }
}

到這里結(jié)束了，這里主要是根據(jù)前臺傳的時(shí)間，進(jìn)行生成cron，入庫，執(zhí)行定時(shí)任務(wù)。但是有一個(gè)問題，就是如果項(xiàng)目重啟了的話，那么定時(shí)類那是無法加載到cron表達(dá)式的。那么接下來，加一個(gè)項(xiàng)目啟動(dòng)時(shí)，把數(shù)據(jù)庫里的cron表達(dá)式重新灌入到定時(shí)類就可以。代碼如下：

复制import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

/**
 * 項(xiàng)目啟動(dòng)時(shí)，加載
 * @Date: 2020/12/25:16:00
 **/
@Component
@Order(1)
public class initLineRunner implements CommandLineRunner {

    @Autowired
    private ScheduleService scheduleService;

    @Override
    public void run(String... args) throws Exception {
        System.out.println("init ........... ");
        //這里就是獲取你數(shù)據(jù)庫里的那個(gè)cron表達(dá)式
        Schedule param = scheduleService.get();
        String cron = param.getCron();
        ScheduleUtil.reset(new ScheduleTask(param.getId().toString(), scheduleService, null), cron);
    }
}

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本文鏈接：

https://blog.csdn.net/bbscz007/article/details/111695289