Every time I use Spring Security, I have to copy and paste a lot of boilerplate code. What if I made the boilerplate code configurable? I decided to venture into this idea.
At first, I extracted only the method body which configures HttpSecurity. So I got myself something like a utility library. But this meant there was still some boilerplate code outside of the library. This approach required consumers to define their own configuration classes (annotated with @Configuration).
I was unable to write an annotation to guide the creation of such configuration classes. It’s because there are restrictions on the types of annotation members.
Giving so much “freedom” to the client offers more room for misunderstanding. As such, I looked into whether I could extract more code into the library. I then stumbled upon Spring Boot Auto-configuration.
Auto-configuration sounded just like the thing I needed - not a library but a custom starter. Consumers only need to specify their configurations in the application.yml file. There is little room for misunderstanding.
First, I annotated my configuration classes with @Configuration and @ConfigurationProperties("someKey"). Then, I created src/main/resources/META-INF/spring.factories. Afterwards, I wrote something like the following into spring.factories:
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
yourTLD.yourOrg.yourProject.somePackage.SomeConfigClass,\
yourTLD.yourOrg.yourProject.somePackage.SomeConfigClass2
I was more or less done, but there were some things I haven’t / won’t solve:
No qualifying bean of type String. I didn’t venture into where I should be placing@Bean,@Qualifieror@Value. It’s because I didn’t want to overwrite my Lombok getters or setters.- Including a controller (i.e. annotated with
@RestController) in the custom starter. - Upon the consumer’s trigger / API call, interact with the client’s database through the controller.