@ConditionalOnProperty conditionally works

Question

I have code like the following:

@Scheduled(cron = "${cron.foo.bar}")
@ConditionalOnProperty(name="cron.foo.bar.enabled", relaxedNames = false)
public void parseFooBar() {
... blah blah blah ...
}

In my properties file, I have:

cron.foo.bar=1 * * * * ?
cron.foo.bar.enabled=false

This does not work, and parseFooBar gets executed every minute on the 1st second.

However, if I add the field:

@Value("${cron.foo.bar.enabled}")
private String enabledProp;

so that I can do a log and see what it is, parseFooBar does NOT get executed. Removing the injected String once again sees parseFooBar execute. What am I doing wrong?

Edit: This is using Spring 4.1.5, Spring Boot 1.2.1, and JDK 8

Edit 2: moving the annotation to the type also works. (without having to force the @Value). But the annotation is both a Method and a Type annotation? It gives me a little more flexibility to do it on the method...

Answer 1

A condition in Spring Framework is used to control whether or not a component is registered in the application context. From the javadoc of @Conditional:

The @Conditional annotation may be used in any of the following ways:

• as a type-level annotation on any class directly or indirectly annotated with @Component, including @Configuration classes
• as a meta-annotation, for the purpose of composing custom stereotype annotations
• as a method-level annotation on any @Bean method

When the condition is declared on parseFooBar it has no effect as it's not a @Bean method. It works as you expect when you declare it on the type as it then makes the component conditional such that it's not registered in the application context when the property doesn't match.