interface Interface {
int INT_CONSTANT = 0; // it's a constant, the same as public static final int INT_FIELD = 0
void instanceMethod1();
void instanceMethod2();
static void staticMethod() {
System.out.println("Interface: static method");
}
default void defaultMethod() {
System.out.println("Interface: default method. It can be overridden");
}
private void privateMethod() {
System.out.println("Interface: private methods in interfaces are acceptable but should have a body");
}
}
Static, default, and private methods should have an implementation in the interface!