JDK 9 pre-review of JDK-6850612: Deprecate Class.newInstance since it violates the checked exception language contract

[Roger Riggs]

Hi Joe,

Wouldn't it be less make work to introduce the new method, replace the 
current one where appropriate
and then deprecate the existing method?  As it is, you/someone is going 
to make a second pass
over all the same files.

Roger


On 4/21/2016 12:25 PM, joe darcy wrote:
> Hello,
>
> After a generally positive reception, please review the webrev to 
> implement the deprecation of Class.newInstance and the suppression of 
> the resulting warnings:
>
>     http://cr.openjdk.java.net/~darcy/6850612.0/
>
> There are also some changes in the langtools repo; I'll send a 
> separate review request for those changes to compiler-dev.
>
> I'll also forward this review request to other areas with affected code.
>
> Thanks,
>
> -Joe
>
> On 4/17/2016 10:31 AM, joe darcy wrote:
>> Hello,
>>
>> With talk of deprecation in the air [1], I thought it would be a fine 
>> time to examine one of the bugs on my list
>>
>>     JDK-6850612: Deprecate Class.newInstance since it violates the 
>> checked exception language contract
>>
>> As the title of the bug implies, The Class.newInstance method 
>> knowingly violates the checking exception contract. This has long 
>> been documented in its specification:
>>
>>> Note that this method propagates any exception thrown by the nullary 
>>> constructor, including a checked exception. Use of this method 
>>> effectively bypasses the compile-time exception checking that would 
>>> otherwise be performed by the compiler. The Constructor.newInstance 
>>> method avoids this problem by wrapping any exception thrown by the 
>>> constructor in a (checked) InvocationTargetException.
>>
>> Roughly, the fix would be to turn the text of this note into the 
>> @deprecated text and to add a @Deprecated(since="9") annotation to 
>> the method. There are a few dozen uses of the method in the JDK that 
>> would have to be @SuppressWarning-ed or otherwise updated.
>>
>> Thoughts on the appropriateness of deprecating this method at this time?
>>
>> Comments on the bug have suggested that besides deprecating the 
>> method, a new method on Class could be introduced, 
>> newInstanceWithProperExceptionBehavior, that had the same signature 
>> but wrapped exceptions thrown by the constructor call in the same way 
>> Constructor.newInstance does.
>>
>> Thanks,
>>
>> -Joe
>>
>> [1] 
>> http://mail.openjdk.java.net/pipermail/core-libs-dev/2016-April/040192.html
>