小贝子编程

以编程方式使用 Spring 调度作业(动态设置 fixedRate)



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取的值，以便无需重新部署应用程序即可更改计划。最好的方法是什么？我意识到使用注释可能是不可能的...

使用Trigger可以动态计算下一次执行时间。

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();
                    }
                }
        );
    }
}

您也可以使用 Spring 表达式语言 （SpEL） 来实现此目的。

初始化此值

后，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";
    }
}

要创建和管理多个动态计划任务，

调度程序配置和 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 Scheduler..." + 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;
    }
}

调度程序服务代码：

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);

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。

您可以使用 TaskScheduler 和 ScheduledFuture 来管理重新启动调度：

@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();
    }
}

启停接口：

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调度程序对象接口进行调度

简单的 Spring 引导示例，限制为秒、分钟和小时间隔。 此示例的目的是演示两个属性（TimeUnit 和间隔）的条件处理。

性能：

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

计划方法：

@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());
    }
}

看看我们如何在MySchedularService类中调用"#{@getIntervalTime}"，并从注释类中获取下一次计划调用的时间间隔@Bean

主类

package com;
import java.util.Calendar;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.scheduling.annotation.EnableScheduling;
@SpringBootApplication
@EnableScheduling
public class SbootSchedularApplication {
    public static void main(String[] args) {
        SpringApplication.run(SbootSchedularApplication.class, args);
    }
    
    @Value("${schedular3Timing}")
    String schedular3Timing;
    
    @Bean
    public String getIntervalTime() 
    {
        long startSchedulerAfterMiliSec = setSchedule(schedular3Timing);
        return ""+startSchedulerAfterMiliSec;
    }
    
    public long setSchedule(String key) 
    {
        int hour = Integer.parseInt(key.substring(0, key.indexOf(":")));
        int min = Integer.parseInt(key.substring(key.indexOf(":") + 1));
        Calendar schedulerCal = Calendar.getInstance();
        schedulerCal.set(Calendar.HOUR, hour);
        schedulerCal.set(Calendar.MINUTE, min);
        schedulerCal.set(Calendar.SECOND, 0);
        
        Calendar localCal = Calendar.getInstance();
        Long currentTimeInMilliSec = localCal.getTime().getTime();
        String currentDayTime = localCal.getTime().toString();
        if (schedulerCal.getTime().getTime() < currentTimeInMilliSec) {         // Means calculating time reference from time 00:00, if current time is 1000 mili-sec and scheduled time is 800 mili-sec -> then that time is already happened, so better add one more day in that same timing.
            schedulerCal.add(Calendar.DATE, 1);         // add 1 day more in the Schedular, if scheduled-MiliSec is less than the current-MiliSec.
        }
        long scheduledTimeInMilliSec = schedulerCal.getTime().getTime();
        String scheduledTime = schedulerCal.getTime().toString();
        System.out.println("** Scheduled start time for the task    : " + scheduledTime + " *** " + scheduledTimeInMilliSec);
        System.out.println("** Current time of the day      : " + currentDayTime + " *** " + currentTimeInMilliSec);
        long startScheduler = scheduledTimeInMilliSec - currentTimeInMilliSec;      // eg: scheduledTime(5pm) - currentTime(3pm) = (2hr)startSchedulerAfter
        return startScheduler;
    }
}
<小时 />

MySchedularService 类 ： 参见 JOB-3

package com.service;
import java.util.Date;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;
@Service
public class MySchedularService {
    private static final Logger logger = LoggerFactory.getLogger(MySchedularService.class);
//  @Scheduled(fixedRate = 2000, initialDelay = 5000L)
    @Scheduled(fixedRateString = "${schedular1.fixedRateInMS}", initialDelay = 1000L)
    public void job() {
        logger.info("Job1 Run Time : " + new Date());
    }
    
//  @Scheduled(fixedRateString = "${schedular2.fixedRateInMS}", initialDelay = 5000L)
//  public void job2() {
//      logger.info("Job2 Run Time : " + new Date());
//  }
    @Scheduled(fixedRate = 10000 , initialDelayString = "#{@getIntervalTime}")      // we can change the fixedRate = 86400000L miliseconds (i.e, one day interval)    
    public void job3() {
        logger.info("**Job2 Run Time : " + new Date());
    }
    
    
}
<小时 />

应用程序属性文件

spring.task.scheduling.pool.size=10
schedular1.fixedRateInMS=3000
schedular2.fixedRateInMS=10000
schedular3Timing=01:07
<小时 />

我从org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler中使用ThreadPoolTaskScheduler创建了动态任务和 scheduleWithFixedDelay 方法。我还添加了一个 Redisson 锁，以防止分布式环境中的重复作业，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;
    }

配置类为：

    @Configuration
    public class AppConfig {
    
        @Bean
        ThreadPoolTaskScheduler taskScheduler(){
            ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler();
            scheduler.setThreadNamePrefix("ThreadPoolTaskScheduler");
            scheduler.setPoolSize(2);
            scheduler.initialize();
            return scheduler;
        }
    
    }

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