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From: "javax.swing.JSnarker" <gharriman@boojum.mit.edu>
Newsgroups: comp.lang.java.programmer
Subject: Re: e==null?  really?
Date: Fri, 13 Jul 2012 17:01:49 -0400
Organization: media lab?
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On 13/07/2012 4:55 PM, Joerg Meier wrote:
> On Fri, 13 Jul 2012 13:11:18 -0700 (PDT), Lew wrote:
>
>>> 	try {
>>> 	    throw null;
>>> 	} catch (Exception e) {
>>> 	    // e is null here!
>>> 	}
>
>>> ... but according to the JLS that shouldn&#39;t have happened.  Bug?
>> It's no more a bug than that you might get a 'ClassCastException' when you cast
>> a value to another type. The compiler allows what the runtime sometimes
>> doesn't.
>
> And there's really no way around that - Exception e = null; if
> (externalCondition()) e = new Exception(); throw e; - can't very well
> complain about that at compile time for arbitrary definitions of
> externalCondition().

Well, there is one; "throw e;" *could* have been specified to compile 
into what you presently get by compiling:

if (e == null)
     throw new NullPointerException();
else
     throw e;

-- 
public final class JSnarker
extends JComponent
A JSnarker is an NNTP-aware component that asynchronously provides 
snarky output when the Ego.needsPuncturing() event is fired in cljp.