Re: Cloneable type parameter?

From:
"Mike Schilling" <mscottschilling@hotmail.com>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 14 Aug 2006 00:07:33 GMT
Message-ID:
<99PDg.635$q63.78@newssvr13.news.prodigy.com>
"Daniel Dyer" <dan@dannospamformepleasedyer.co.uk> wrote in message
news:op.td8n7pqignpvuy@jack.local...

On Sun, 13 Aug 2006 20:41:22 +0100, Stefan Schmiedl <s@xss.de> wrote:

I should have seen this coming, since Cloneable is an empty interface,
and the docs state that

 * By _convention_, classes that implement this interface should override
 * Object.clone (which is protected) with a public method.

I guess nobody told javac about this _convention_ ... must be human
thing.

I would like to make the compiler ensure that RestorableObject is
only wrapped around objects providing a clone() method. I can do
this by introducing an interface


Cloning in Java was not very well thought-out. You could use reflection
to invoke the clone method.


Note, though, that clone() (by default, at least) is a shallow clone, so
changes made to objects that are fields of your working copy may not be
undone by reverting to your original. What might work better for you
(depending on your requirements, which are unstated) is to save the object
by writing it to a DataOutputStream, and restoring it by reading it back
from that stream. This will do the equivalent of a deep clone, and works
for many objects that do not implement Clonable.

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