Spring Framework FAQ: Top Questions

Dependency Injection (DI) is a design pattern in which objects receive their dependencies from an external source rather than creating them internally. Spring implements DI to achieve loose coupling and greater testability.

📘 Types of Injection:

• Constructor Injection
• Setter Injection
• Field Injection (not recommended)

📥 Example:

public class Car {
  private Engine engine;

  @Autowired
  public Car(Engine engine) {
    this.engine = engine;
  }
}

🏆 Expected Output:

Spring injects the Engine bean into Car via constructor.

🛠️ Use Cases:

• Promotes cleaner and more testable code.
• Allows decoupling of components.