1 public class Student { 2  3     public static void main(String[] args) { 4         Faculty f= new Math(); 5         f.SetCourse(new BasisOfComputerEngineering()); 6         f.urriculum(); 7     } 8 } 9 10 //选课11 interface CurriculaVariable{12     //所有课程的抽象方法13     void urriculum();14 }15 //各门课程16 class BasisOfComputerEngineering implements CurriculaVariable{17 18     @Override19     public void urriculum() {20         System.out.println("选择了计算机基础");21     }22 }23 24 //系25 abstract class Faculty implements CurriculaVariable{26     //系中聚合选课27     protected CurriculaVariable cv;28     public void SetCourse(CurriculaVariable cv) {29         this.cv = cv;30     }31 }32 //数学系33 class Math extends Faculty{34 35     @Override36     public void urriculum() {37         System.out.println("数学系选课");38         ((CurriculaVariable) cv).urriculum();39     }40     41 }

输出为：