由图10-1~10-3可以看出,@Component注解在注册Bean的流程中涉及到ComponentTest类、AnnotationConfigApplicationContext类、AbstractApplicationContext类、PostProcessorRegistrationDelegate类、ConfigurationClassPostProcessor类、ConfigurationClassParser类、SourceClass类、ComponentScanAnnotationParser类、ClassPathBeanDefinitionScanner...
@component . however, other areas of spring look specifically for spring’s specialized annotations to provide additional automation benefits. so, we should probably stick with using the established specializations most of the time. let’s assume we have an example of each of these cases in our ...
1.4. @Controller annotation @Controllerannotation marks a class as a Spring Web MVC controller. It too is a@Componentspecialization, so beans marked with it are automatically imported into the DI container. When we add the@Controllerannotation to a class, we can use another annotation i.e.@Req...
@Component:组件,表示此写上了此注解的bean,作为一个组件存在于容器中。这样的话别的地方就可以使用@Resource这个注解来把这个组件作为一个资源来使用了。初始化bean的名字为类名首字母小写 与@Component注解功能相同的注解有:@Repository,@Service,@Controller,@Component ,默认情况下Spring认为这4个注解会被认为是一...
源码详见:org.springframework.context.annotation.ComponentScans,如下所示。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 /*** * @author Juergen Hoeller * @since 4.3 * @see ComponentScan */@Retention(RetentionPolicy.RUNTIME)@Target(ElementType.TYPE)@Documentedpublic@interfaceComponentScans{Componen...
import javax.annotation.Resource; import org.springframework.stereotype.Component; import com.yusj.dao.IUserDAO; import com.yusj.model.User; /** * 使用@Component实现把普通类实例化到spring容器中,相当于配置文件中的<bean id="" class=""/> ...
从源码可以看出,@Component注解是从Spring2.5版本开始提供的注解,并且@Component注解只能标注到类上。其中只含有一个String类型的value属性,具体含义如下所示。 value:用于指定注入容器时Bean的id。如果没有指定Bean的id,默认值为当前类的名称。 @Component注解提供了三个衍生注解:分别是:@Repository、@Service和@Controlle...
<mvc:annotation-driven/>和<context:component-scan> 那么<context:annotation-config/>呢? 首先看一下三个注解各自定义: ①<context:annotation-config/> 1.如果你想使用@Autowired注解,那么就必须事先在 spring 容器中声明 AutowiredAnnotationBeanPostProcessor Bean。
@Resource是JSR250的注解,它被spring支持。 JSR是Java Specification Requests的缩写,意思是Java 规范提案,是Java界的一个重要标准。关于JSR250可以参见The Java Community Process(SM) Program 【Resource-常用】 Resource表示在此处使用了一个资源,它默认是byName方式,找不到则会变为byType。存在于javax.annotation包中...
For this, Spring provides PersistenceExceptionTranslationPostProcessor, which we are required to add in our application context (already included if we’re using Spring Boot): <bean class= "org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor"/> This bean post processor adds ...