DefaultMethode

DefaultMethod is a feature introduced in Java 8 that allows interfaces to have methods with an implementation. Prior to Java 8, interfaces could only contain abstract methods, which meant that any class implementing the interface had to provide concrete implementations for all the methods declared in the interface. This limitation could lead to code duplication and made it difficult to evolve interfaces without breaking existing implementations.

With the introduction of DefaultMethod, interfaces can now include methods with a default implementation. These methods are defined using the default keyword and can provide a default behavior that can be inherited by any class implementing the interface. This allows for more flexible and evolvable interfaces, as new methods can be added to an interface without requiring changes to all implementing classes.

DefaultMethod can be particularly useful in scenarios where multiple interfaces might define methods with the same signature, and a class needs to implement both interfaces. Without DefaultMethod, this would result in a diamond problem, where the class would have to provide its own implementation for the conflicting methods. With DefaultMethod, one of the interfaces can provide a default implementation, resolving the conflict.

However, it's important to note that DefaultMethod should be used judiciously. Overuse of DefaultMethod can lead to complex and hard-to-maintain code, as it can make it difficult to understand where a particular method implementation is coming from. Additionally, DefaultMethod can lead to issues if a class inherits conflicting default methods from multiple interfaces. In such cases, the class must provide its own implementation for the conflicting methods.