What is difference between @ImportAutoConfiguration and @Import

Question

Is it true that org.springframework.boot.autoconfigure.ImportAutoConfiguration is improved replacement for org.springframework.context.annotation.Import because does the same and additionally respects

@AutoConfigureBefore, @AutoConfigureAfter and @AutoConfigureOrder ?

Answer 1

Is it true that org.springframework.boot.autoconfigure.ImportAutoConfiguration is improved replacement for org.springframework.context.annotation.Import?

No it is not a replacement since @ImportAutoConfiguration is a Spring Boot specific annotation, I might call it an enhancement. But eventhough it seems that you can use them interchangeably when using Spring Boot, I wouldn't suggest it. Use them as they were intended to be used.

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You would use @ImportAutoConfiguration when you don't want to enable the default autoconfiguration with @EnableAutoConfiguration. As you probably know, @EnableAutoConfiguration attemps to configure beans that are located on your classpath eg tomcat-embedded.jar. Whereas @ImportAutoConfiguration only runs the configuration classes that you provided in the annotation.

This is an example of an Spring Boot application main method with @ImportAutoConfiguration:

@ComponentScan("path.to.your.controllers")
@ImportAutoConfiguration({WebMvcAutoConfiguration.class
    , DispatcherServletAutoConfiguration.class
    , EmbeddedServletContainerAutoConfiguration.class
    , ServerPropertiesAutoConfiguration.class
    , HttpMessageConvertersAutoConfiguration.class})
public class App {
  public static void main(String[] args) {
    SpringApplication.run(App.class, args);
  }
}

You might say that it is an alternative to using @EnableAutoConfiguration. And in this case to configure barebone embedded Tomcat and Spring WebMVC.

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@Import is used to import a bean configuration class marked with @Configuration which contains your custom bean configurations.