@Component, @Repository & 之间有什么区别?Spring 中的 @Service 注释? [英] What's the difference between @Component, @Repository & @Service annotations in Spring?
问题描述
可以@Component
, @Repository
和 @Service
注释在 Spring 中可以互换使用,还是除了充当注释设备之外还提供任何特定功能?
Can @Component
, @Repository
and @Service
annotations be used interchangeably in Spring or do they provide any particular functionality besides acting as a notation device?
换句话说,如果我有一个 Service 类并且我将注释从 @Service
更改为 @Component
,它的行为是否仍然相同?
In other words, if I have a Service class and I change the annotation from @Service
to @Component
, will it still behave the same way?
或者注解是否也会影响类的行为和功能?
Or does the annotation also influence the behavior and functionality of the class?
推荐答案
来自 Spring 文档:
@Repository
注释是任何满足存储库的角色或构造型(也称为数据访问对象或 DAO).此标记的用途之一是自动翻译异常,如 异常翻译.
The
@Repository
annotation is a marker for any class that fulfils the role or stereotype of a repository (also known as Data Access Object or DAO). Among the uses of this marker is the automatic translation of exceptions, as described in Exception Translation.
Spring 提供了更多的构造型注解:@Component
、@Service
、和 @Controller
.@Component
是任何的通用构造型Spring 管理的组件.@Repository
、@Service
和 @Controller
是@Component
的专门化,用于更具体的用例(在分别为持久层、服务层和表示层).因此,您可以使用 @Component
注释您的组件类,但是,通过使用 @Repository
、@Service
或 @Controller
注释它们相反,您的类更适合由工具处理或与方面相关联.
Spring provides further stereotype annotations: @Component
, @Service
,
and @Controller
. @Component
is a generic stereotype for any
Spring-managed component. @Repository
, @Service
, and @Controller
are
specializations of @Component
for more specific use cases (in the
persistence, service, and presentation layers, respectively).
Therefore, you can annotate your component classes with @Component
,
but, by annotating them with @Repository
, @Service
, or @Controller
instead, your classes are more properly suited for processing by tools
or associating with aspects.
比如这些构造型注释为切入点制作理想的目标.@Repository
、@Service
和@Controller
还可以在未来的版本中携带额外的语义弹簧框架.因此,如果您在使用之间进行选择@Component
或 @Service
对于您的服务层,@Service
显然是更好的选择.同样,如前所述,@Repository
已经是支持作为自动异常翻译的标记持久层.
For example, these stereotype annotations
make ideal targets for pointcuts. @Repository
, @Service
, and
@Controller
can also carry additional semantics in future releases of
the Spring Framework. Thus, if you are choosing between using
@Component
or @Service
for your service layer, @Service
is clearly the
better choice. Similarly, as stated earlier, @Repository
is already
supported as a marker for automatic exception translation in your
persistence layer.
注释 | 含义 |
---|---|
@Component | 任何 Spring 管理组件的通用构造型 |
@Repository | 持久层的原型 |
@Service | 服务层的原型 |
@Controller | 表示层的原型(spring-mvc) |
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