a.java

Java 程序设计源码 只提供了部分

class A
{
	void fn1()
	{
	        System.out.println("A");
	}
}

abstract class B
{
	abstract void fn2();
}

class C extends A
{
        B getB()
        {
                return new B()
                {
                        public void fn2()
                        {
                                System.out.println("B");
                        }
                };
        }
}

class main
{
        static void Method1(A a)
        {
                a.fn1();
        }
        
        static void Method2(B b)
        {
                b.fn2();
        }
        public static void main(String[] args)
        {
                C c = new C();
                Method1(c);
                Method2(c.getB());
                
        }
}