内部接口(笔记)

java.util.Map接口，通过内部接口实现。

 interface  xx{

     ...

    interface yy{

       ...

    }

}

例子：

/** 
 * 接口与内部接口 工厂方法 
 * 
 * @author xiaofeng.zhouxf 
 */ 
interface InnerOne {

    Print getPrint();

    interface Print {

        void printOut(); 
    } 
} 
----------------------------------------------------

 

/** 
 * 内部类 实现内部接口 
 * 
 * @author xiaofeng.zhouxf 
 */

public class InnerOneImpl implements InnerOne {

    public static InnerOneImpl one;

    public static InnerOneImpl getInstance() { 
        if (one == null) one = new InnerOneImpl(); 
        return one; 
    }

    public Print getPrint() { 
        return new Print(); 
    }

    class Print implements InnerOne.Print {

        public void printOut() { 
              System.out.println("innerOne............"); 
        }

    } 
}

-------------------------------------------------

/** 
 * 匿名内部类 实现内部接口 
 * 
 * @author xiaofeng.zhouxf 
 */

public class InnerOneImpl2 implements InnerOne {

    public static InnerOneImpl2 one;

    public static InnerOneImpl2 getInstance() { 
        if (one == null) one = new InnerOneImpl2(); 
        return one; 
    }

    public Print getPrint() { 
        // TODO Auto-generated method stub 
        return new Print() {// 实现了Print内部接口的匿名内部类

            public void printOut() { 
                // TODO Auto-generated method stub 
                System.out.println("innerTwo............"); 
            } 
        }; 
    } 
}

-----------------------------------------------------

public class InnerMainTest {

    public static void main(String... strings) { 
        InnerOne one = InnerOneImpl.getInstance(); 
        InnerOne one2 = InnerOneImpl2.getInstance(); 
        one.getPrint().printOut(); 
        one2.getPrint().printOut(); 
    } 
}

----------------------------------------------------

打印结果：

innerOne............ 
innerTwo............