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继续问土问题# Java - 爪哇娇娃

r*w2003-05-12 07:05

1 楼

怎样能够得知一个object的class呢？
就是说我有一个object
我要on the fly new 一个deep copy of it...
so i have to call the related constructor...
but I want the implementation quite generic...
i know i can do
if obj instanceof Class1
then new_obj=new Class1(obj)
else if obj instanceof Class2
then new_obj=new Class2(obj)
etc...
any other more elegant solution?

m*t2003-05-12 07:05

2 楼

You can call obj.getClass() to get the Class object for obj.
(quite a tongue twister isn't it)
But you'll have to make sure each of the classes you need to copy
has a default constructor, otherwise you'll still end up checking
classes.

【在 r*******w 的大作中提到】

: 怎样能够得知一个object的class呢？
: 就是说我有一个object
: 我要on the fly new 一个deep copy of it...
: so i have to call the related constructor...
: but I want the implementation quite generic...
: i know i can do
: if obj instanceof Class1
: then new_obj=new Class1(obj)
: else if obj instanceof Class2
: then new_obj=new Class2(obj)

r*w2003-05-12 07:05

3 楼

then call newInstance of the Class object?
sounds good ah...
thanks~~~

【在 m******t 的大作中提到】

:
: You can call obj.getClass() to get the Class object for obj.
: (quite a tongue twister isn't it)
: But you'll have to make sure each of the classes you need to copy
: has a default constructor, otherwise you'll still end up checking
: classes.