Register Spring Beans

Starting from 2.0, Spring provides an option to detect beans by scanning the classpath. Developers can use annotations (e.g. @Component) to register bean definitions in the Spring container and this removes the use of XML. We can use @Component which is a generic stereotype annotation or those specialized stereotype annotation: @Controller, @Service, or @Repository for presentation, service, persistence layer, respectively. These annotations work equally for registering beans but using specialized annotation makes your classes suited for processing by tools.

When you register a bean, its bean scope is a "singleton" by default if you don't specify it. Our service class is stateless so that it is suitable to be a singleton-scoped bean. For those beans used in composers, they should use scoped-proxy to ensure every time Spring will retrieve them when a composer uses them. (Please use scoped-proxy even for a singleton scoped bean, because scope of Spring beans doesn't match scope of composers. Scoped-proxy can ensure composers get the latest bean under their context. For furthermore explanation, please refer to Developer's Reference/Integration/Middleware Layer/Spring )

public class AuthenticationServiceImpl implements AuthenticationService,Serializable{
  • Line 1: You could specify bean's name in @Service or its bean is derived from class name with first character in lower case (e.g. authenticationServiceImpl in this case).
  • Line 2: If you want to specify a bean's scope, use @Scope. For those beans used in composers, you should use scoped-proxy to ensure every time you get the latest bean.