Quick Answer: What Is Difference Between @Component And @Bean?

Are all spring beans singletons?

Spring’s default scope is singleton.

Here is how the Spring documentation defines singleton scope: Only one shared instance of a singleton bean is managed, and all requests for beans with an id or ids matching that bean definition result in that one specific bean instance being returned by the Spring container..

What is difference between @component and @configuration?

@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.

Can we use @component instead of @repository?

The difference between them is, @component is used to annotate compound classes, @Repository is a marker for automatic exception translation in the persistence layer, for service layer we need to use @service. You can refer Spring Documentation to know more.

Can we replace @service with @component?

You can use @Service over @Component in service-layer classes as it specifies intent in a better way. @Repository: This annotation is a specialization of the @Component annotation with similar use and functionality. It provides additional benefits specifically for DAOs.

Can we replace @controller with @component?

2 Answers. @Controller is a @Component (just like @Service , @Repository , @Endpoint etc.). The @Component is used as a meta-annotation here so that it can be picked-up using component-scanning. Next to that the @Controller is a special component which will have some added functionality (Spring MVC takes care of that).

Is @component a singleton?

Yes, that is correct, @Component is a Spring bean and a Singleton. About singletons – spring beans are all in singleton scope by default.

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.

Is Spring beans are thread safe?

So eventually thread safety depends on the code and the code only. And this is the reason why Spring beans are not thread safe per se. Spring singleton beans are NOT thread-safe just because Spring instantiates them. … Spring just manage the life cycle of singleton bean and maintains single instance of object.

What is the use of @component annotation?

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.

What is spring bean life cycle?

Advertisements. The life cycle of a Spring bean is easy to understand. When a bean is instantiated, it may be required to perform some initialization to get it into a usable state. Similarly, when the bean is no longer required and is removed from the container, some cleanup may be required.

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 bean in spring with example?

A bean is an object that is instantiated, assembled, and otherwise managed by a Spring IoC container. These beans are created with the configuration metadata that you supply to the container. For example, in the form of XML definitions which you have already seen in the previous chapters.

What is use of @component in Spring?

@Component is the most generic Spring annotation. A Java class decorated with @Component is found during classpath scanning and registered in the context as a Spring bean. @Service , @Repository , and @Controller are specializations of @Component , which are used for more specific cases.

What is difference between @component and @service 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. @Controller is a stereotype for the presentation layer (spring-MVC).

How many ways can you make a bean in spring?

Spring Framework provides three ways to configure beans to be used in the application. Annotation Based Configuration – By using @Service or @Component annotations. Scope details can be provided with @Scope annotation. XML Based Configuration – By creating Spring Configuration XML file to configure the beans.

What does the Spring bean lifecycle look like?

Bean life cycle is managed by the spring container. When we run the program then, first of all, the spring container gets started. After that, the container creates the instance of a bean as per the request and then dependencies are injected. And finally, the bean is destroyed when the spring container is closed.

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.

How do you kill spring beans?

To do this initialization and destroy routine you can use the init-method and destroy-method attribute when declaring a bean in spring configuration using the element. By defining the init-method and destroy-method it will allow the Spring Container to call the initialization method right after the bean created.