How to Organize Spring Boot Projects for Seamless Component Scanning

Typical Example

Spring Boot does not impose a specific project layout, but following a recommended package structure helps avoid configuration pitfalls, especially with Spring's component scanning.

com
+-example
   +-myproject
      +-Application.java
      |
      +-domain
         +-Customer.java
         +-CustomerRepository.java
      |
      +-service
         +-CustomerService.java
      |
      +-web
         +-CustomerController.java

The root package (e.g., com.example.myproject) contains all other packages.

The main application class resides in the root package, allowing Spring Boot to automatically scan it and its sub‑packages.

If classes are placed outside the root package, they will not be discovered by default.

Initializing Non‑Typical Structures

When you must load beans from packages outside the root package, you can explicitly specify the packages to scan.

Method 1 – @ComponentScan

@SpringBootApplication
@ComponentScan(basePackages = "com.example")
public class Bootstrap {
    public static void main(String[] args) {
        SpringApplication.run(Bootstrap.class, args);
    }
}

This directly tells Spring which packages to scan, but the conventional structure is still recommended.

Method 2 – @Bean

@SpringBootApplication
public class Bootstrap {
    public static void main(String[] args) {
        SpringApplication.run(Bootstrap.class, args);
    }

    @Bean
    public CustomerController customerController() {
        return new CustomerController();
    }
}

Using @Bean to create beans manually is less common in typical business development and is more suitable for framework extensions.