What are the differences between Java annotations and interfaces?

What are the differences between Java annotations and interfaces?

Java annotations are metadata that provide information about the program but do not affect its execution. Interfaces, on the other hand, define a contract that classes must follow, specifying methods that must be implemented.

Can you give me examples of when to use annotations?

Sure! Annotations are often used for configuration in frameworks like Spring, for marking methods with @Override, or for defining custom behaviors in libraries.

What about interfaces? When should I use them?

Use interfaces when you want to define a common behavior for different classes. They allow for polymorphism and can help in designing flexible systems.

Are there any performance differences between using annotations and interfaces?

Generally, annotations have minimal performance impact since they are processed at compile-time or runtime. Interfaces may have a slight overhead due to method calls, but this is usually negligible.

Can I use annotations in interfaces?

Yes, you can use annotations in interfaces to provide metadata about the interface itself or its methods.