Java Garage

How to Write an Interface

The Java API is full of terrific interface definitions. One commonly used interface is java.lang.Runnable, which can be implemented to create a thread. To write an interface, you can look at the many good examples in the Java API.

When writing your own, you just use the keyword interface instead of class, and then don't include the method implementations. Like this:

public interface MyInterface {
      public void someMethod(long someParam);
}

As you can see, you just use the interface keyword in place of class. And then you substitute a semi-colon for the curly braces holding the method implementation. That's all you have to do in a nutshell. In the following sections, we'll see the many twisting, cavernous corridors that ...