86

目前我有这个：

@Scheduled(fixedRate=5000)
public void getSchedule(){
   System.out.println("in scheduled job");
}

我可以将其更改为使用对属性的引用

@Scheduled(fixedRateString="${myRate}")
public void getSchedule(){
   System.out.println("in scheduled job");
}

但是，我需要使用以编程方式获得的值，以便可以在不重新部署应用程序的情况下更改计划。什么是最好的方法？我意识到使用注释可能是不可能的......

4

7 回答 7

131

使用 aTrigger您可以即时计算下一个执行时间。

像这样的东西应该可以解决问题（改编自Javadoc for@EnableScheduling）：

@Configuration
@EnableScheduling
public class MyAppConfig implements SchedulingConfigurer {

    @Autowired
    Environment env;

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

    @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().getSchedule();
                    }
                },
                new Trigger() {
                    @Override public Date nextExecutionTime(TriggerContext triggerContext) {
                        Calendar nextExecutionTime =  new GregorianCalendar();
                        Date lastActualExecutionTime = triggerContext.lastActualExecutionTime();
                        nextExecutionTime.setTime(lastActualExecutionTime != null ? lastActualExecutionTime : new Date());
                        nextExecutionTime.add(Calendar.MILLISECOND, env.getProperty("myRate", Integer.class)); //you can get the value from wherever you want
                        return nextExecutionTime.getTime();
                    }
                }
        );
    }
}
于 2013-01-31T18:35:29.873 回答
21

您也可以为此使用 Spring 表达式语言 (SpEL)。

初始化此值后，您将无法更新此值。

@Scheduled(fixedRateString = "#{@applicationPropertyService.getApplicationProperty()}")
public void getSchedule(){
   System.out.println("in scheduled job");
}

@Service
public class ApplicationPropertyService {

    public String getApplicationProperty(){
        //get your value here
        return "5000";
    }
}
于 2019-12-06T08:52:30.993 回答
12

要创建和管理多个动态计划任务，

计划配置和bean：

import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.Trigger;
import org.springframework.scheduling.TriggerContext;
import org.springframework.scheduling.annotation.SchedulingConfigurer;
import org.springframework.scheduling.config.ScheduledTaskRegistrar;

import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

@Configuration
@EnableScheduling
public class SchedulingConfigs implements SchedulingConfigurer {

    @Override
    public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
        taskRegistrar.addTriggerTask(new Runnable() {
            @Override
            public void run() {
                // Do not put @Scheduled annotation above this method, we don't need it anymore.
                System.out.println("Running Schedular..." + Calendar.getInstance().getTime());
            }
        }, new Trigger() {
            @Override
            public Date nextExecutionTime(TriggerContext triggerContext) {
                Calendar nextExecutionTime = new GregorianCalendar();
                Date lastActualExecutionTime = triggerContext.lastActualExecutionTime();
                nextExecutionTime.setTime(lastActualExecutionTime != null ? lastActualExecutionTime : new Date());
                nextExecutionTime.add(Calendar.MILLISECOND, getNewExecutionTime());
                return nextExecutionTime.getTime();
            }
        });
    }

    private int getNewExecutionTime() {
        //Load Your execution time from database or property file
        return 1000;
    }

    @Bean
    public TaskScheduler poolScheduler() {
        ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler();
        scheduler.setThreadNamePrefix("ThreadPoolTaskScheduler");
        scheduler.setPoolSize(1);
        scheduler.initialize();
        return scheduler;
    }
}

调度服务代码：

package io.loadium.resource.service;

import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.context.event.EventListener;
import org.springframework.scheduling.TaskScheduler;
import org.springframework.stereotype.Service;

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

@Service
public class ScheduleTaskService {

    // Task Scheduler
    TaskScheduler scheduler;

    // A map for keeping scheduled tasks
    Map<Integer, ScheduledFuture<?>> jobsMap = new HashMap<>();

    public ScheduleTaskService(TaskScheduler scheduler) {
        this.scheduler = scheduler;
    }


    // Schedule Task to be executed every night at 00 or 12 am
    public void addTaskToScheduler(int id, Runnable task, Date runningDate) {
        ScheduledFuture<?> scheduledTask = scheduler.schedule(task, runningDate);
        jobsMap.put(id, scheduledTask);
    }

    // Remove scheduled task
    public void removeTaskFromScheduler(int id) {
        ScheduledFuture<?> scheduledTask = jobsMap.get(id);
        if (scheduledTask != null) {
            scheduledTask.cancel(true);
            jobsMap.put(id, null);
        }
    }

    // A context refresh event listener
    @EventListener({ContextRefreshedEvent.class})
    void contextRefreshedEvent() {
        // Get all tasks from DB and reschedule them in case of context restarted
    }
}

示例用法：

// Add a new task with runtime after 10 seconds
scheduleTaskService.addTaskToScheduler(1, () -> System.out.println("my task is running -> 1"), , Date.from(LocalDateTime.now().plusSeconds(10).atZone(ZoneId.systemDefault()).toInstant()));
// Remove scheduled task
scheduleTaskService.removeTaskFromScheduler(1);
于 2020-09-18T09:21:38.747 回答
9

您也可以使用这种简单的方法：

private int refreshTickNumber = 10;
private int tickNumber = 0; 

@Scheduled(fixedDelayString = "${some.rate}")
public void nextStep() {
    if (tickNumber < refreshTickNumber) {
        tickNumber++;
        return;
    }
    else {
        tickNumber = 0;
    }
    // some code
}

refreshTickNumber在运行时是完全可配置的，并且可以与@Value注释一起使用。

于 2017-03-05T08:52:31.460 回答
9

您可以使用 TaskScheduler 和 ScheduledFuture 管理重新启动计划：

@Configuration
@EnableScheduling
@Component
public class CronConfig implements SchedulingConfigurer , SchedulerObjectInterface{

    @Autowired
    private ScheduledFuture<?> future;

     @Autowired
        private TaskScheduler scheduler;

    @Bean
    public SchedulerController schedulerBean() {
        return new SchedulerController();
    }

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

        @Override
    public void start() {
        future = scheduler.schedule(new Runnable() {
            @Override
            public void run() {
                //System.out.println(JOB + "  Hello World! " + new Date());
                schedulerBean().schedulerJob();
            }
        }, new Trigger() {
            @Override public Date nextExecutionTime(TriggerContext triggerContext) {
                Calendar nextExecutionTime =  new GregorianCalendar();
                Date lastActualExecutionTime = triggerContext.lastActualExecutionTime(); 
           nextExecutionTime.setTime(convertExpresssiontoDate());//you can get the value from wherever you want
                return nextExecutionTime.getTime();
            }
        });

    }


    @Override
    public void stop() {
        future.cancel(true);

    }

    @Override
    public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
        // TODO Auto-generated method stub
        start();
    }

}

启停界面：

public interface SchedulerObjectInterface {    
    void start();
    void stop();
}

现在您可以停止并重新开始（重新启动）使用@Autowired SchedulerObjectInterface 进行调度

于 2017-10-25T06:54:39.953 回答
1

简单的 Spring Boot 示例限制为秒、分钟和每小时间隔。此示例的目的是演示两个属性 TimeUnit 和间隔的条件处理。

特性：

snapshot.time-unit=SECONDS
snapshot.interval=5

预定方法：

@Scheduled(cron = "*/1 * * * * *")
protected void customSnapshotScheduler()
{
    LocalDateTime now = LocalDateTime.now();
    TimeUnit timeUnit = TimeUnit.valueOf(snapshotProperties.getSnapshot().getTimeUnit());
    int interval = snapshotProperties.getSnapshot().getInterval();

    if (TimeUnit.SECONDS == timeUnit
            && now.getSecond() % interval == 0)
    {
        this.camService.writeSnapshot(webcam.getImage());
    }

    if (TimeUnit.MINUTES == timeUnit
            && now.getMinute() % interval == 0)
    {
        this.camService.writeSnapshot(webcam.getImage());
    }

    if (TimeUnit.HOURS == timeUnit
            && now.getHour() % interval == 0)
    {
        this.camService.writeSnapshot(webcam.getImage());
    }
}
于 2019-09-01T14:11:36.587 回答
0

我使用 ThreadPoolTask​​Scheduler fromorg.springframework.scheduling.concurrent.ThreadPoolTaskScheduler 和 scheduleWithFixedDelay 方法创建了动态任务。我还添加了一个 redisson 锁，以防止在分布式环境中重复作业这是我的代码：

public class TaskRunnerService {

    private final ThreadPoolTaskScheduler taskScheduler;
    private final RedissonClient redissonClient;


    public TaskRunnerService(ThreadPoolTaskScheduler taskScheduler, RedissonClient redissonClient) {
        this.taskScheduler = taskScheduler;
        this.redissonClient = redissonClient;
    }

    @PostConstruct
    public void runTasks() {
        List<TaskDTO> taskDTOS = TaskHolder.createTasks();
        for (TaskDTO taskDTO : taskDTOS) {
            RLock lock = this.redissonClient.getFairLock("LoadAndRunScheduleService-" + taskDTO.getId());

            if (lock.tryLock()) {
                try {
                    this.taskScheduler.scheduleWithFixedDelay(() -> {
                        System.out.println(" running task " + taskDTO.getId() + " with delay " + taskDTO.getDelay() + " at " + new Date());
                    }, taskDTO.getDelay() * 1000L);
                }finally {
                    lock.unlock();
                }
            }
        }
    }

}

我创建了一个 TaskDTO 类，以便能够在运行时获得延迟：

import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;

    @AllArgsConstructor
    @NoArgsConstructor
    @Getter
    @Setter
    public class TaskDTO {
    
        private int id;
        private int delay;
    }

和配置类是：

    @Configuration
    public class AppConfig {
    
        @Bean
        ThreadPoolTaskScheduler taskScheduler(){
            ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler();
            scheduler.setThreadNamePrefix("ThreadPoolTaskScheduler");
            scheduler.setPoolSize(2);
            scheduler.initialize();
            return scheduler;
        }
    
    }
于 2021-10-30T07:38:02.467 回答