Injecting externalized value into Spring annotation

Question

I\'ve been thinking around the Java feature that evaluates annotation values in compile-time and it seems to really make difficult externalizing annotation values.

H

Answer 1

If you want to make this work with annotation rather than bean configuration xml, you can use the following annotations: @Component, @PropertySource with PropertySourcesPlaceholderConfigurer Bean itself, like this:

@Component
@PropertySource({ "classpath:scheduling.properties" })
public class SomeClass {

    @Scheduled(fixedDelay = "${delay}")
    public void someMethod(){
        // perform something
    }

    @Bean
    public static PropertySourcesPlaceholderConfigurer placeHolderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
    }   
}