What is the role of a proxy in Spring and what tasks is it used for?

In Spring, proxies are used to implement aspect-oriented programming (AOP), manage transactions, lazy initialization, and other cross-cutting concerns.

Role of proxies:

• Wrap the original object (Spring beans) and intercept method calls.
• Allow injecting additional behavior (e.g., logging, security checks, transaction management) without modifying the source code.

In Spring, proxies are created automatically when using annotations like @Transactional or during aspect configuration.

Example:

@Service
public class UserService {
    @Transactional
    public void createUser() {
        // business logic
    }
}

When createUser is called, Spring creates a proxy that begins a transaction before executing the method and commits or rolls it back afterward depending on the result.

Thus, proxies in Spring enable injecting additional logic around methods without changing their code.