Question: What Is @Qualifier In Spring?

What is the difference between @qualifier and @primary?

@Primary is also good if e.g.

95% of @Autowired wants a particular bean.

That way, only the @Autowired that wants the other bean(s) need to specify @Qualifier .

That way, you have primary beans that all autowired wants, and @Qualifier is only used to request an “alternate” bean..

What is use of @repository in spring?

@Repository is a Spring annotation that indicates that the decorated class is a repository. A repository is a mechanism for encapsulating storage, retrieval, and search behavior which emulates a collection of objects.

What is spring bean life cycle?

A “Spring bean” is just a Spring managed instantiation of a Java class. The Spring IoC container is responsible for instantiating, initializing, and wiring beans. The container also manages the life cycle of beans. Spring provides several ways through which you can tap into the bean lifecycle.

What is a bean in spring?

In Spring, the objects that form the backbone of your application and that are managed by the Spring IoC container are called beans. A bean is an object that is instantiated, assembled, and otherwise managed by a Spring IoC container. Otherwise, a bean is simply one of many objects in your application.

What is @controller in spring?

Controller – A controller contains the business logic of an application. Here, the @Controller annotation is used to mark the class as the controller. … Front Controller – In Spring Web MVC, the DispatcherServlet class works as the front controller. It is responsible to manage the flow of the Spring MVC application.

What is the use of qualifier?

A qualifier is a word that limits or enhances another word’s meaning. Qualifiers affect the certainty and specificity of a statement. Overusing certain types of qualifiers (for example, very or really) can make a piece of writing sound lazily constructed.

What is the difference between @configuration and @component in Spring?

@Component Indicates that an annotated class is a “component”. Such classes are considered as candidates for auto-detection when using annotation-based configuration and classpath scanning. A @Configuration is also a @Component, but a @Component cannot act like a @Configuration.

What is difference between @controller and @RestController in spring?

Difference between @RestController and @Controller in Spring. … The @Controller is a common annotation that is used to mark a class as Spring MVC Controller while @RestController is a special controller used in RESTFul web services and the equivalent of @Controller + @ResponseBody.

What is the purpose of @qualifier in spring?

There may be a situation when you create more than one bean of the same type and want to wire only one of them with a property. In such cases, you can use the @Qualifier annotation along with @Autowired to remove the confusion by specifying which exact bean will be wired.

What is @service annotation in spring?

Spring @Service annotation is used with classes that provide some business functionalities. Spring context will autodetect these classes when annotation-based configuration and classpath scanning is used.

What is the difference between @service and @component in Spring?

Difference between @Component, @Service, @Controller, and @Repository in Spring. … @Component is a generic stereotype for any Spring-managed component or bean. @Repository is a stereotype for the persistence layer. @Service is a stereotype for the service layer.

What are the modules in spring?

The Spring Framework consists of features organized into about 20 modules. These modules are grouped into Core Container, Data Access/Integration, Web, AOP (Aspect Oriented Programming), Instrumentation, and Test, as shown in the following diagram.

What is difference between @bean and @component?

Both approaches aim to register target type in Spring container. The difference is that @Bean is applicable to methods, whereas @Component is applicable to types. Therefore when you use @Bean annotation you control instance creation logic in method’s body (see example above). With @Component annotation you cannot.

What is a component in spring?

Spring Component annotation is used to denote a class as Component. It means that Spring framework will autodetect these classes for dependency injection when annotation-based configuration and classpath scanning is used. 1 Spring Component.

Can we have two beans with same name in spring?

Spring would not let you define multiple bean definitions of same bean with same name in the same spring configuration file.

What is difference between @inject and @autowired?

The @Autowired annotation is used for auto-wiring in Spring framework. … The @Inject annotation also serves the same purpose, but the main difference between them is that @Inject is a standard annotation for dependency injection and @Autowired is spring specific.