根据official doc：

Annotation Type Configuration

Indicates that a class declares one or more @Bean methods and may be
processed by the Spring container to generate bean definitions…

@Configuration classes may be composed using the @Import annotation,
not unlike the way that works in Spring XML. Because
@Configuration objects are managed as Spring beans within the
container..

但我也可以在没有@Import的情况下使用@Configuration注释.我已经测试了下面列出的代码,它按预期工作.那么使用@Import的目的是什么？

DispatcherServletInitializer

public class ApplicationInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
    @Override
    protected Class

@Configuration
@EnableWebMvc
@ComponentScan(basePackages = { "package.name" })
// @Import(OptionalConfig.class) 
public class WebConfig extends WebMvcConfigurerAdapter {
    // ...
}

@Configuration
public class OptionalConfig {
    @Bean(name = "myClass")
    public MyClass myClass() {
        return new MyClass();
    }
}

@Service
public class MyServiceImpl implements MyService {
    @Autowired
    private MyClass myClass;    // yes,it works
    // ...
}