@Component vs. @Bean in Spring: When to Use Which Annotation?

Bean Management in Spring: @Component and @Bean

In Spring, bean management has evolved over the years, with the introduction of @Component and @Bean annotations. While their purpose both revolves around bean creation, there are distinct differences in their usage.

@Component

The @Component annotation, introduced in Spring 2.5, enables component scanning. This means that Spring automatically discovers and registers beans based on annotations such as @Service, @Repository, and @Controller. It is commonly used for automatically creating and wiring beans in simple applications.

@Bean

The @Bean annotation, introduced in Spring 3.0, is used in conjunction with @Configuration. It allows developers to define beans explicitly within a Java configuration class. This provides more control over bean definition and initialization, especially when working with third-party libraries that cannot be annotated with @Component.

Could @Component Have Sufficed Instead of @Bean?

While @Component and @Bean both create beans, it would not have been appropriate to reuse the @Component annotation for the following reasons:

• Explicit Bean Definition: @Bean allows for more explicit bean definition, including method-based initialization logic. This is essential when working with third-party libraries or creating complex beans.
• Declarative vs. Imperative: @Component supports declarative bean definition through annotations, while @Bean provides imperative bean definition through methods. This distinction enables greater flexibility and control over bean creation.

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