如何在Spring中使用EnableScheduling注释在运行时重新启动计划任务？

Question

我一直在研究如何使用Java 8和spring在运行时更改作业的频率.这个问题非常有用,但并没有完全解决我的问题.

我现在可以配置下次执行作业的日期.但是如果将延迟设置为1年,那么我需要在考虑新配置之前等待1年.

我的想法是在配置值发生变化时停止计划任务(所以从另一个类开始).然后在下次执行任务时重新计算.也许有一种更简单的方法可以做到这一点.

这是我到目前为止的代码.

@Configuration
@EnableScheduling
public class RequestSchedulerConfig implements SchedulingConfigurer {

    @Autowired
    SchedulerConfigService schedulerConfigService;

    @Bean
    public RequestScheduler myBean() {
        return new RequestScheduler();
    }

    @Bean(destroyMethod = "shutdown")
    public Executor taskExecutor() {
        return Executors.newScheduledThreadPool(100);
    }

    @Override
    public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
        taskRegistrar.setScheduler(taskExecutor());
        taskRegistrar.addTriggerTask(
                new Runnable() {
                    @Override public void run() {
                        myBean().startReplenishmentComputation();
                    }
                },
                new Trigger() {
                    @Override public Date nextExecutionTime(TriggerContext triggerContext) {
                        Duration d = schedulerConfigService.getIntervalFromDB();
                        return DateTime.now().plus(d).toDate();
                    }
                }
        );
    }
}

这就是我想做的事情.

@RestController
@RequestMapping("/api/config/scheduler")
public class RequestSchedulerController {

    @Autowired
    ApplicationConfigWrapper applicationConfigWrapper;

    @RequestMapping("/set/")
    @ResponseBody
    public String setRequestSchedulerConfig(@RequestParam(value = "frequency", defaultValue = "") final String frequencyInSeconds){
        changeValueInDb(frequencyInSeconds);
        myJob.restart();
        return "Yeah";
    }

}

Answer 1

1. 创建一个注入的单例bean TaskScheduler.这将持有的状态变量的所有ScheduledFutures ^,如private ScheduledFuture job1;
2. 在部署时,从数据库加载所有计划数据并启动作业,填写所有状态变量,如job1.
3. 在调度数据的改变时,取消相应的Future(例如job1),然后用新的调度数据再次启动它.

这里的关键思想是在Future创建s时控制它们,以便将它们保存在某些状态变量中,这样当调度数据中的某些内容发生变化时,您可以取消它们.

这是工作代码:

applicationContext.xml中

<task:annotation-driven />
<task:scheduler id="infScheduler" pool-size="10"/>

单身豆,持有Futures

@Component
public class SchedulerServiceImpl implements SchedulerService {

        private static final Logger logger = LoggerFactory.getLogger(SchedulerServiceImpl.class);

        @Autowired
        @Qualifier(value="infScheduler")
        private TaskScheduler taskScheduler;

        @Autowired
        private MyService myService;

        private ScheduledFuture job1;//for other jobs you can add new private state variables

        //Call this on deployment from the ScheduleDataRepository and everytime when schedule data changes.
        @Override
        public synchronized void scheduleJob(int jobNr, long newRate) {//you are free to change/add new scheduling data, but suppose for now you only want to change the rate
                if (jobNr == 1) {//instead of if/else you could use a map with all job data
                        if (job1 != null) {//job was already scheduled, we have to cancel it
                                job1.cancel(true);
                        }
                        //reschedule the same method with a new rate
                        job1 = taskScheduler.scheduleAtFixedRate(new ScheduledMethodRunnable(myService, "methodInMyServiceToReschedule"), newRate);
                }
        }
}