What Is Difference Between @Component And @Configuration?

What is difference between @component and @bean?

@Component is a class level annotation whereas @Bean is a method level annotation and name of the method serves as the bean name.

@Component need not to be used with the @Configuration annotation where as @Bean annotation has to be used within the class which is annotated with @Configuration..

Is @component a singleton?

2 Answers. Yes, that is correct, @Component is a Spring bean and a Singleton. About singletons – spring beans are all in singleton scope by default. The only thing you have to have in mind is that you should not store state in field variables (they should only hold dependencies).

What is @bean used for?

@Bean is a method-level annotation and a direct analog of the XML element. The annotation supports most of the attributes offered by , such as: init-method , destroy-method , autowiring , lazy-init , dependency-check , depends-on and scope .

Can we replace @service with @component?

According to documentaion @Repository , @Service , @Controller are all synonyms. They all just specializations of @Component annotation. So, generally, they can be used one istead of other. But … you should not do this.

What is the use of @controller annotation?

The basic purpose of the @Controller annotation is to act as a stereotype for the annotated class, indicating its role. The dispatcher will scan such annotated classes for mapped methods, detecting @RequestMapping annotations (see the next section).

Can we use @component instead of @controller?

“@Component serves as a generic stereotype for any Spring-managed component; whereas, @Repository, @Service, and @Controller serve as specializations of @Component for more specific use cases (e.g., in the persistence, service, and presentation layers, respectively).

What is difference between @component and @controller?

@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).

What is @controller in spring boot?

@Controller annotation indicates that the annotated class is a controller. It is a specialization of @Component and is autodetected through classpath scanning. It is typically used in combination with annotated handler methods based on the @RequestMapping annotation.

What is the use of @component?

@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 the use of @repository?

@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 use of @autowired in spring?

Advertisements. The @Autowired annotation provides more fine-grained control over where and how autowiring should be accomplished. The @Autowired annotation can be used to autowire bean on the setter method just like @Required annotation, constructor, a property or methods with arbitrary names and/or multiple arguments …

What is use of @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.

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 @component and @autowired?

The @Autowired annotation allows the container to automatically inject the message property from the application-context. xml file. … The @Component tells that Message is a component, a bean whose object has to be created. The “msgObject” is the name of the created object.

What does @repository annotation do?

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.

What is @ComponentScan?

The @ComponentScan annotation is used with the @Configuration annotation to tell Spring the packages to scan for annotated components. @ComponentScan also used to specify base packages and base package classes using thebasePackageClasses or basePackages attributes of @ComponentScan.

What is the use of @component annotation?

@Component This annotation is used on classes to indicate a Spring component. The @Component annotation marks the Java class as a bean or component so that the component-scanning mechanism of Spring can add it into the application context.

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.