@Import注解作用

理解springboot自动装配时，发现@SpringBootApplication注解下的@EnableAutoConfiguration注解头上有一个@Import注解。

关于这个注解的作用，上网查找后发现理解的不是很明白，于是写了下面的Demo去理解。

两个pojo类：

public class Person {
}public class Student {
}

测试类

@Configuration
@Import({Student.class})
public class ImportConfig {@Beanpublic Person person(){return new Person();}public static void main(String[] args) {AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(ImportConfig.class,ApplicationTestConfig.class);String[] names = context.getBeanDefinitionNames();Student student = ApplicationTestConfig.getApplication(Student.class);System.out.println("===="+student);for (String name : names) {System.out.println(name);}}}

ApplicationTestConfig类如下：

@Configuration
public class ApplicationTestConfig implements ApplicationContextAware {private static ApplicationContext applicationContext;@Overridepublic void setApplicationContext(ApplicationContext applicationContext) throws BeansException {this.applicationContext = applicationContext;}public static <T> T getApplication(Class<T> clazz){return applicationContext.getBean(clazz);}}

测试结果

====com.yjh.pojo.Student@649bec2e
org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.annotation.internalCommonAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
importConfig
applicationTestConfig
com.yjh.pojo.Student
person