How to change Spring's @Scheduled fixedDelay at runtime?
In spring boot, you can use an application property directly!
For example:
@Scheduled(fixedDelayString = "${my.property.fixed.delay.seconds}000")
private void process() {
// your impl here
}
Note that you can also have a default value in case the property isn't defined, eg to have a default of "60" (seconds):
@Scheduled(fixedDelayString = "${my.property.fixed.delay.seconds:60}000")
Other things I discovered:
- the method must be void
- the method must have no parameters
- the method may be
private
I found being able to use private
visibility handy and used it in this way:
@Service
public class MyService {
public void process() {
// do something
}
@Scheduled(fixedDelayString = "${my.poll.fixed.delay.seconds}000")
private void autoProcess() {
process();
}
}
Being private
, the scheduled method can be local to your service and not become part of your Service's API.
Also, this approach allows the process()
method to return a value, which a @Scheduled
method may not. For example, your process()
method can look like:
public ProcessResult process() {
// do something and collect information about what was done
return processResult;
}
to provide some information about what happened during processing.
You can use a Trigger
to dynamically set the next execution time.
See my answer to Scheduling a job with Spring programmatically for details.
create interface , something like that:
public abstract class DynamicSchedule{
/**
* Delays scheduler
* @param milliseconds - the time to delay scheduler.
*/
abstract void delay(Long milliseconds);
/**
* Decreases delay period
* @param milliseconds - the time to decrease delay period.
*/
abstract void decreaseDelayInterval(Long milliseconds);
/**
* Increases delay period
* @param milliseconds - the time to increase dela period
*/
abstract void increaseDelayInterval(Long milliseconds);
}
Next, lets implement Trigger interface that is located at org.springframework.scheduling in the spring-context project.
import org.springframework.scheduling.TaskScheduler;
import org.springframework.scheduling.Trigger;
import org.springframework.scheduling.TriggerContext;
import java.util.Date;
import java.util.concurrent.ScheduledFuture;
public class CustomDynamicSchedule extends DynamicSchedule implements Trigger {
private TaskScheduler taskScheduler;
private ScheduledFuture<?> schedulerFuture;
/**
* milliseconds
*/
private long delayInterval;
public CustomDynamicSchedule(TaskScheduler taskScheduler) {
this.taskScheduler = taskScheduler;
}
@Override
public void increaseDelayInterval(Long delay) {
if (schedulerFuture != null) {
schedulerFuture.cancel(true);
}
this.delayInterval += delay;
schedulerFuture = taskScheduler.schedule(() -> { }, this);
}
@Override
public void decreaseDelayInterval(Long delay) {
if (schedulerFuture != null) {
schedulerFuture.cancel(true);
}
this.delayInterval -= delay;
schedulerFuture = taskScheduler.schedule(() -> { }, this);
}
@Override
public void delay(Long delay) {
if (schedulerFuture != null) {
schedulerFuture.cancel(true);
}
this.delayInterval = delay;
schedulerFuture = taskScheduler.schedule(() -> { }, this);
}
@Override
public Date nextExecutionTime(TriggerContext triggerContext) {
Date lastTime = triggerContext.lastActualExecutionTime();
return (lastTime == null) ? new Date() : new Date(lastTime.getTime() + delayInterval);
}
}
now configuration:
@Configuration
public class DynamicSchedulerConfig {
@Bean
public CustomDynamicSchedule getDynamicScheduler() {
ThreadPoolTaskScheduler threadPoolTaskScheduler = new ThreadPoolTaskScheduler();
threadPoolTaskScheduler.initialize();
return new CustomDynamicSchedule(threadPoolTaskScheduler);
}
}
and usage:
@EnableScheduling
@Component
public class TestSchedulerComponent {
@Autowired
private CustomDynamicSchedule dynamicSchedule;
@Scheduled(fixedDelay = 5000)
public void testMethod() {
dynamicSchedule.delay(1000l);
dynamicSchedule.increaseDelayInterval(9000l);
dynamicSchedule.decreaseDelayInterval(5000l);
}
}
You can also use Spring Expression Language (SpEL) for this.
@Scheduled(fixedDelayString = "#{@applicationPropertyService.getApplicationProperty()}")
public void getSchedule(){
System.out.println("in scheduled job");
}
@Service
public class ApplicationPropertyService {
public String getApplicationProperty(){
//get your value here
return "5000";
}
}
AFAIK the Spring API won't let you access the internals you need to change the trigger. But you could instead configure manually the beans:
<bean id="simpleTrigger" class="org.springframework.scheduling.quartz.SimpleTriggerBean">
<property name="jobDetail" ref="jobDetail" />
<property name="startDelay" value="10000" />
<property name="repeatInterval" value="50000" />
</bean>
<bean class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
<property name="triggers">
<list>
<ref bean="simpleTrigger" />
</list>
</property>
</bean>
Then as documented in SchedulerFactoryBean:
For dynamic registration of jobs at runtime, use a bean reference to this SchedulerFactoryBean to get direct access to the Quartz Scheduler (
org.quartz.Scheduler
). This allows you to create new jobs and triggers, and also to control and monitor the entire Scheduler.