别的不说，singleton 没答好，有点儿说不过去。

In Java, the latest Singleton pattern, use enum instead of a regular class. It's that simple.

The reasoning based on Joshua's is that serialization can cause issues. If a class implements Serializable, then after serialized and deserialized, a new instance can be created if the instance variables are not transient.

If you can answer the above, you will be guaranteed to pass the Singleton question.

Good luck.

所有跟帖： 

• 谢师祖教诲。 -吴用先生- ♂ (0 bytes) () 03/04/2009 postreply 22:09:19

• 回复：别的不说，singleton 没答好，有点儿说不过去。 -ncpga- ♂ (158 bytes) () 03/05/2009 postreply 09:26:00

• It was a C++ interview, -吴用先生- ♂ (467 bytes) () 03/05/2009 postreply 10:44:10

• why it needs a copy ctor? why make copy constructor "protected" -戏雨飞鹰- ♀ (356 bytes) () 03/05/2009 postreply 11:50:35

• the interviewer said -吴用先生- ♂ (186 bytes) () 03/05/2009 postreply 12:31:48

• ok. -戏雨飞鹰- ♀ (0 bytes) () 03/05/2009 postreply 12:40:14

• 师祖爷呀，你的singleton说得也忒深奥了。够俺回味好几年得了。。 ~~~ -戏雨飞鹰- ♀ (26 bytes) () 03/05/2009 postreply 12:18:58

• 是啊是啊，也很高兴飞鹰姐姐亲临指导，没想到 -吴用先生- ♂ (48 bytes) () 03/05/2009 postreply 12:34:56

• 看似容易，其实还是有点学问的。 -mdq100- ♂ (170 bytes) () 03/05/2009 postreply 20:21:33

• 噢，谢谢。我还真没用过serialization /deserialization -戏雨飞鹰- ♀ (762 bytes) () 03/05/2009 postreply 20:43:54

• basiaclly yes. -mdq100- ♂ (237 bytes) () 03/05/2009 postreply 20:55:48

• Thanks, 100... -戏雨飞鹰- ♀ (0 bytes) () 03/05/2009 postreply 20:58:13

• nonsense, 又不用你发明singleton. 知道singleton是什么意思,会COPY$PASTE 就行. -bluemont- ♂ (0 bytes) () 03/05/2009 postreply 19:28:02

• 这么复杂？那COPY$PASTE是８是很难？哈哈。。 -戏雨飞鹰- ♀ (69 bytes) () 03/05/2009 postreply 20:00:33

• 只要不谩骂，欢迎交流。换马甲也没关系。 -mdq100- ♂ (0 bytes) () 03/05/2009 postreply 20:17:12