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From: supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com>
Newsgroups: comp.lang.java.programmer
Subject: Re: Why "lock" functionality is introduced for all the objects?
Date: Wed, 29 Jun 2011 01:12:13 -0400
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On 28/06/2011 4:43 PM, BGB wrote:
> yeah...
>
> they made every object lockable but not every object cloneable, where
> one would think cloning would be generally a higher priority.

If they'd been smarter about managing mutability to begin with (e.g. 
fields immutable by default, objects normally immutable) cloning would 
not be a priority at all.

Sure, the boxed primitives and Strings are immutable, and that's about 
it. We've got mutable stuff out the wazoo, most of which probably 
shouldn't be -- java.util.Date, anyone? Not to mention java.awt.Point 
and friends. All those conundrums about whether Square should be a 
subclass of Rectangle, or Circle of Ellipse, go away if they aren't 
mutable. Then they clearly are subclasses. Mutable collections and 
arrays also make type reasoning more complicated and don't allow casting 
a List<Sub> to a List<Super> as then you might add a non-Sub Super to 
the list. If the list wasn't mutable there'd be no problem casting a 
List<Sub> to a List<Super>.

I could go on...but I won't.