Unable to use #ConfigurationProperties in #Scheduled annotation - spring

Question

I'm using a #ConfigurationProperties to define the property my.delay.
#ConfigurationProperties( "my" )
public class MyProperties {
private long delay = 1000L;
public long getDelay() {
return delay;
}
public void setDelay(long delay) {
this.delay = delay;
}
}
In the scheduler method I try to use my.delay:
#SpringBootApplication
#EnableScheduling
#EnableConfigurationProperties( { MyProperties.class } )
public class TestSprPropApplication {
public static void main(String[] args) {
SpringApplication.run(TestSprPropApplication.class, args);
}
#Scheduled( fixedDelayString = "${my.delay}" )
public void schedule() {
System.out.println( "scheduled" );
}
}
Then the following error arises:
Caused by: java.lang.IllegalStateException: Encountered invalid #Scheduled method 'schedule': Could not resolve placeholder 'my.delay' in string value "${my.delay}"
at org.springframework.scheduling.annotation.ScheduledAnnotationBeanPostProcessor.processScheduled(ScheduledAnnotationBeanPostProcessor.java:454) ~[spring-context-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.scheduling.annotation.ScheduledAnnotationBeanPostProcessor.postProcessAfterInitialization(ScheduledAnnotationBeanPostProcessor.java:324) ~[spring-context-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:423) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1633) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]

Answer 1

You can solve it using a SpEL expression that references a bean using #beanName.
You would use it that way:
#Scheduled(fixedDelayString = "#{#myProperties.delay}")
Notice that #{} is used (SpEL expression) instead of ${} (property placeholder).

Answer 2

Im not sure if there is a solution for your approach. But to simplify your code and also have a default value you can go like that:
No need to have MyProperty file at all. You can delete it.
Update your #Scheduled annotation with this default value:
#Scheduled( fixedDelayString = "${my.delay:1000}" )
This means if Spring does not find a property of my.delay it uses the default value after the :. In your case its 1000.
And if you like to override the default value just add the property in your application.properties file:
my.delay=5000