【Spring源码解析】组件注册-@ComponentScan注册bean

前言

接上一篇 Spring源码解析之注解注册bean

实现

1. 按照平时的开发, 我们创建几个类

@Controller
public class BookController {
}

@Service
public class BookService {
}

@Repository
public class BookDao {
}

2. 配置

@Configuration
@ComponentScan(value = "cn.idea360")
public class BeanConfig {

    @Bean
    public Person person() {
        return new Person("config", 18);
    }
}

3. 引入单元测试

<dependency>
    <groupId>org.junit.jupiter</groupId>
    <artifactId>junit-jupiter</artifactId>
    <version>RELEASE</version>
    <scope>test</scope>
</dependency>

4. 测试

class IocTest {

    @Test
    public void test01() {
        AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(BeanConfig.class);
        String[] beanDefinitionNames = applicationContext.getBeanDefinitionNames();
        for (String name: beanDefinitionNames) {
            System.out.println(name);
        }
    }
}

输出结果

org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
beanConfig
bookController
bookDao
bookService
person

可以看出我们添加了注解并在指定包下的bean全部被注册进了容器

5. 如果我们想按注解排除一部分

@Configuration
@ComponentScan(value = "cn.idea360", excludeFilters = {
        @ComponentScan.Filter(type = FilterType.ANNOTATION, value = {Controller.class})
})
public class BeanConfig {

    @Bean
    public Person person() {
        return new Person("config", 18);
    }
}

最后

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