With concrete or abstract classes, inner classes are the only way to produce the effect of multiple implementation inheritance. : Nested Classes « Class Definition « Java Tutorial






class D {
}

abstract class E {
}

class Z extends D {
  E makeE() {
    return new E() {
    };
  }
}

public class MainClass {
  static void takesD(D d) {
  }

  static void takesE(E e) {
  }

  public static void main(String[] args) {
    Z z = new Z();
    takesD(z);
    takesE(z.makeE());
  }
}








5.14.Nested Classes
5.14.1.Creating instances of inner classes
5.14.2.Nested Classes
5.14.3.Creating a new nested object outside
5.14.4.Static Nested Classes
5.14.5.Creating inner classes
5.14.6.Defining references to inner classes
5.14.7.Nesting a class within a method
5.14.8.Nesting a class within a scope.
5.14.9.Nested classes (static inner classes)
5.14.10.An inner class cannot be overriden like a method
5.14.11.Two ways that a class can implement multiple interfaces
5.14.12.Nested classes can access all members of all levels of the classes they are nested within
5.14.13.Proper inheritance of an inner class.
5.14.14.Using inner classes for callbacks
5.14.15.Returning a reference to an inner class
5.14.16.Putting test code in a nested class
5.14.17.With concrete or abstract classes, inner classes are the only way to produce the effect of multiple implementation inheritance.
5.14.18.Local inner class can have a constructor