Difference between @Bean and @Component annotation in Spring.

SpringObject Oriented ProgrammingProgramming

 Spring supports multiple types annotations such as @Component,@Controller,@service @Repository and @Bean. All theses can be found under the org.springframework.stereotype package.

When classes in our application are annotated with any of the above mentioned annotation then during project startup spring scan(using @componentScan) each class and inject the instance of the classes to the IOC container. Another thing the @ComponentScan would do is running the methods with @Bean on it and restore the return object to the Ioc Container as a bean.

Sr. No.Key@Bean@Component
1
Auto detection
It is used to explicitly declare a single bean, rather than letting Spring do it automatically. 
If any class is annotated with @Component it will be automatically detect by using classpath scan.
2
Spring Container
Bean can be created even class is outside the spring container
We can’t create bean if class is outside spring container
3
Class/Method  Level Annotation
It is a method level annotation
It is a class level annotation
4
@Configuration
It works only when class is also annotated with @Configuration
It works without
@Configuration annotation
5
Use Case
We should use @bean, if you want specific implementation based on dynamic condition.
We can’t write specific implementation based on dynamic condition

Example of @Component

@Component
public class Pizza{

   ........


}

Example of @Bean

@Configuration
class AppConfiguration{

   @Bean
   public User getUse(){
      return new User();
   }
}
raja
Published on 09-Sep-2020 12:24:20
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