1. Introduction
In this quick tutorial, we’ll show how to use an @EnableConfigurationProperties annotation with @ConfigurationProperties annotated classes.
2. Purpose of @EnableConfigurationProperties Annotation
@EnableConfigurationProperties annotation is strictly connected to @ConfiguratonProperties.
It enables support for @ConfigurationProperties annotated classes in our application. However, it’s worth to point out that the Spring Boot documentation says, every project automatically includes @EnableConfigurationProperties. Therefore, @ConfiguratonProperties support is implicitly turned on in every Spring Boot application.
In order to use a configuration class in our project, we need to register it as a regular Spring bean.
First of all, we can annotate such a class with @Component. Alternatively, we can use a @Bean factory method.
However, in certain situations, we may prefer to keep a @ConfigurationProperties class as a simple POJO. This is when @EnableConfigurationProperties comes in handy. We can specify all configuration beans directly on this annotation.
This is a convenient way to quickly register @ConfigurationProperties annotated beans.
3. Using @EnableConfigurationProperties
Now, let’s see how to use @EnableConfigurationProperties in practice.
First, we need to define our example configuration class:
@ConfigurationProperties(prefix = "additional")
public class AdditionalProperties {
private String unit;
private int max;
// standard getters and setters
}
Note that we annotated the AdditionalProperties only with @ConfigurationProperties. It’s still a simple POJO!
Finally, let’s register our configuration bean using @EnableConfigurationProperties:
@Configuration
@EnableConfigurationProperties(AdditionalProperties.class)
public class AdditionalConfiguration {
@Autowired
private AdditionalProperties additionalProperties;
// make use of the bound properties
}
That’s all! We can now use AdditionalProperties like any other Spring bean.
4. Conclusion
In this quick tutorial, we presented a convenient way to quickly register a @ConfigurationProperties annotated class in Spring.
As usual, all the examples used in this article are available over on GitHub.
