Use of @PostConstruct in Spring Boot
====================================
In Spring Boot, @PostConstruct
is used to annotate a method that should be executed after dependency injection is complete and before the bean is put into service.
Example:
Suppose we have a class UserService
that requires some initialization logic after its dependencies are injected. We can use @PostConstruct
to annotate a method for this purpose.
import javax.annotation.PostConstruct;
import org.springframework.stereotype.Service;
@Service
public class UserService {
@PostConstruct
public void init() {
// Initialization logic, e.g., loading configuration, setting up resources, etc.
System.out.println("UserService initialized!");
}
// Other methods of UserService
}
In this example:
- The
UserService
class is annotated with@Service
to indicate it as a Spring-managed bean. - The
init
method is annotated with@PostConstruct
, ensuring it runs automatically after all dependencies ofUserService
are injected by Spring. - Any initialization logic needed for
UserService
can be placed within theinit
method.
Conclusion:
@PostConstruct
in Spring Boot provides a convenient way to perform initialization tasks for a bean after its dependencies are injected. It ensures that the initialization logic is executed exactly once before the bean is used, contributing to the robustness and reliability of the application.