Unable to use @ConfigurationProperties in @Scheduled annotation

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