Java interfaces are different from classes, and it’s important to know how to use their special properties in your Java programs. This tutorial introduces the difference between classes and ...

In Java, we can implement the functional interface with a lambda expression and pass it to a method, then execute the function after an operation is finished. Here’s how that looks in code: ...

In Java, there are many, many places in which a piece of code needs a single method implementation. And there are many interfaces in the Java API where only a single method needs to be implemented.

There is a reason why Java method modifiers exist. If you call public methods internally and don't understand why, ... And an implementation public class CreateOrderServiceImpl implements ...