The use of spring annotation @Service annotation

 To illustrate the use of the @Service annotation, we have to say that we often see the configuration in the following figure in the spring configuration file applicationContext.xml:

<!-- Using scanning + annotation for development can improve development efficiency, later maintenance becomes difficult, and readability deteriorates -->
<context:component-scan base-package="com.study.persistent" />

 After adding this line to the applicationContext.xml configuration file, the package under the specified path will be automatically scanned. If a class is annotated with @Service, it will be automatically registered to the Spring container, and there is no need to define beans in the applicationContext.xml configuration file. Yes, and similar ones include @Component, @Repository, and @Controller.

Such as this class:

@Service("courseDAO")
@Scope("prototype")
public class CourseDAOImpl extends HibernateDaoSupport implements CourseDAO{
......
}

 Its role is equivalent to configuring the following information in the applicationContext.xml configuration file:

<bean id="courseDAO"
      class="com.study.persistent.CourseDAOImpl" scope="prototype">
      ......    
</bean>

 The @Service("serviceName") annotation is equivalent to the <bean id="serviceName"> configured in the applicationContext.xml configuration file, indicating that the current class is named an alias, which is convenient for injection into other classes that need to be used. The @Service annotation can also not specify serviceName. If you do not specify it is equivalent to <bean id="com.study.service.serviceName">, com.study.service.ServiceName is the fully qualified name of this class. If it is not added, the default alias It is the current class name, but the first letter is lowercase.