Learn why the @Bean annotation is essential in Spring Boot. Discover when to use @Bean, how it differs from @Component, and how it helps define Spring-managed beans manually.

Ramesh Fadatare

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4 min read

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Mar 9, 2025

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🚀 Introduction

In Spring Boot, the @Bean annotation is used to manually define and manage Spring beans. While Spring automatically detects components using annotations like @Component, @Service, and @Repository, sometimes we need more control over bean creation.

So, when should you use @Bean instead of @Component? This guide will explain why, when, and how to use the @Bean annotation effectively.

What is the @Bean Annotation?

The @Bean annotation in Spring Boot defines a Spring-managed bean inside a configuration class.

✔ It is used inside a class annotated with @Configuration.
✔ The method annotated with @Bean returns an object that Spring registers as a bean.
✔ Unlike @Component, @Bean gives full control over bean creation.

When to Use @Bean in Spring Boot?

You should use @Bean in the following cases:

✅ 1. When You Need to Configure a Third-Party Library

If you need to integrate a library that does not have Spring annotations, you must manually define its bean.

✅ 2. When You Need to Customize Bean Creation

You may need to pass custom parameters while creating a bean, which is not possible with @Component.

✅ 3. When Using Java-Based Configuration Instead of Component Scanning

If you prefer explicit Java-based configuration, @Bean helps define beans programmatically instead of relying on automatic scanning.

How to Use @Bean in Spring Boot?

✅ Example 1: Defining a Simple Bean

@Configuration
public class AppConfig {

    @Bean
    public String sampleBean() {
        return "Hello, Spring Boot!";
    }
}