SpringBoot基于数据库实现定时任务过程解析

@Configuration
@EnableScheduling
public class SimpleScheduleTask {
 
  //10秒钟执行一次
  @Scheduled(cron = "0/10 * * * * ?")
  private void tasks() {
    System.out.println("【定时任务】 每10秒执行一次！");
  }
}

@Lazy(value = false)
@Component
public class ScheduleTask implements SchedulingConfigurer {
 
  protected static Logger logger = LoggerFactory.getLogger(ScheduleTask.class);
  private SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
 
  @Autowired
  private ScheduleTaskMapper scheduleTaskMapper;
 
  @Override
  public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
    List<ScheduleTask> tasks = getAllScheduleTasks();
    logger.info("【定时任务启动】 启动任务数："+tasks.size()+"; time="+sdf.format(new Date()));
 
    //校验数据
    checkDataList(tasks);
    //通过校验的数据执行定时任务
    int count = 0;
    if(tasks.size()>0) {
      for (int i = 0; i < tasks.size(); i++) {
        try {
          taskRegistrar.addTriggerTask(getRunnable(tasks.get(i)), getTrigger(tasks.get(i)));
          count++;
        } catch (Exception e) {
          logger.error("task start error:" + tasks.get(i).getClassName() + ";" + tasks.get(i).getMethodName() + ";" + e.getMessage());
        }
      }
    }
    logger.info("started task number="+count+"; time="+sdf.format(new Date()));
  };
 
 /**
 * 获取要执行的所有任务
 * @return
 */
  private List<ScheduleTask> getAllScheduleTasks() {
    ScheduleTaskExample example=new ScheduleTaskExample();
    example.createCriteria().andIsDeleteEqualTo((byte) 0);
    return scheduleTaskMapper.selectByExample(example);
  }
  
 /**
 * 获取Runnable
 *
 * @param task
 * @return
 */
  private Runnable getRunnable(ScheduleTask task){
    return new Runnable() {
      @Override
      public void run() {
        try {
          Object obj = SpringUtil.getBean(task.getClassName());
          Method method = obj.getClass().getMethod(task.getMethodName(),null);
          method.invoke(obj);
        } catch (InvocationTargetException e) {
          logger.error("refect exception:"+task.getClassName()+";"+task.getMethodName()+";"+ e.getMessage());
        } catch (Exception e) {
          logger.error(e.getMessage());
        }
      }
    };
  }
 
 /**
 * 获取Trigger
 *
 * @param task
 * @return
 */
  private Trigger getTrigger(ScheduleTask task){
    return new Trigger() {
      @Override
      public Date nextExecutionTime(TriggerContext triggerContext) {
        //将Cron 0/1 * * * * ?
        CronTrigger trigger = new CronTrigger(task.getCron());
        Date nextExec = trigger.nextExecutionTime(triggerContext);
        return nextExec;
      }
    };
  }
  
 /**
 * 校验数据
 *
 * @param list
 * @return
 */
  private List<ScheduleTask> checkDataList(List<ScheduleTask> list) {
    String msg="";
    for(int i=0;i<list.size();i++){
      if(!checkOneData(list.get(i)).equalsIgnoreCase("ok")){
        msg+=list.get(i).getTaskName()+";";
        list.remove(list.get(i));
        i--;
      };
    }
    if(!StringUtils.IsEmpty(msg)){
      msg="未启动的任务:"+msg;
      logger.error(msg);
    }
    return list;
  }
 
 /**
 * 按每一条校验数据
 *
 * @param task
 * @return
 */
  private String checkOneData(ScheduleTask task){
    String result="ok";
    Class cal= null;
    try {
      cal = Class.forName(task.getClassName());
      Object obj =SpringUtil.getBean(cal);
      Method method = obj.getClass().getMethod(task.getMethodName(),null);
      String cron=task.getCron();
      if(StringUtils.isBlank(cron)){
        result="no found the cron:"+task.getTaskName();
        logger.error(result);
      }
    } catch (ClassNotFoundException e) {
      result="not found the class:"+task.getClassName()+ e.getMessage();
      logger.error(result);
    } catch (NoSuchMethodException e) {
      result="not found the method:"+task.getClassName()+";"+task.getMethodName()+";"+ e.getMessage();
      logger.error(result);
    } catch (Exception e) {
     logger.error(e.getMessage());
     }
    return result;
  }
}