sorry, typo: first line should be: "I don't think we will be able to
automate this,"
Dinesh Patil wrote:
> I don't this we will be able to automate this, as this requires
> opening smaller projects under glassfish, attach the rule file to
> Query and Refactor for Jackpot Transformation and accept the valid
> transformations (as there are few formatting changes we may not need
> to take), verify those manually and then apply transformations. So
> there is some manual check, setup required in this process, but if you
> know any better pls let us know.
> thanks
> Dinesh
>
> kedar wrote:
>
>> We should definitely do this. Is automating this like
>> FindBugs a possibility?
>>
>> Kedar
>>
>> Dinesh Patil wrote:
>>
>>> Dear Module owners and Developers,
>>>
>>> For removing the excessive use of these objects using "new
>>> Boolean(), new Integer(), new Byte() .. " we are experimenting the
>>> NetBeans Jackpot Transformation tool : http://jackpot.netbeans.org/
>>> to replace code as below to use the objects from Cache.
>>>
>>> // Effective Java, Item 4: Avoid creating duplicate objects
>>> new java.lang.Boolean($b) => java.lang.Boolean.valueOf($b);
>>> new java.lang.Byte($b) => java.lang.Byte.valueOf($b);
>>> new java.lang.Character($c) => java.lang.Character.valueOf($c);
>>> new java.lang.Integer($i) => java.lang.Integer.valueOf($i);
>>> new java.lang.Long($l) => java.lang.Long.valueOf($l);
>>> new java.lang.Short($s) => java.lang.Short.valueOf($s);
>>> new java.lang.String($s) => $s :: $s instanceof java.lang.String;
>>>
>>> You can refer to the email thread for more details. Jan and myself
>>> tried this on appserv-jstl and appserv-commons modules, and I could
>>> find following diffs where this transformation matches and replaces
>>> in appserv-commons module.
>>>
>>> http://glassfishbuildtools.sun.com:8000/jackpot_acommons.log
>>>
>>> We will be running this transformation on all the modules, so if you
>>> have any comments, suggestions or if you prefer to do it yourself on
>>> your own modules please let me know.
>>> thanks
>>> Dinesh
>>>
>>>> Hi Tom,
>>>> Tom Ball wrote On 10/17/06 14:04,:
>>>>
>>>>> Charlie is right: these sorts of transformations are trivial and
>>>>> safe for Jackpot to do. Here are the relevant rules:
>>>>>
>>>>> // Effective Java, Item 4: Avoid creating duplicate objects
>>>>> new java.lang.Boolean($b) => java.lang.Boolean.valueOf($b);
>>>>> new java.lang.Byte($b) => java.lang.Byte.valueOf($b);
>>>>> new java.lang.Character($c) => java.lang.Character.valueOf($c);
>>>>> new java.lang.Integer($i) => java.lang.Integer.valueOf($i);
>>>>> new java.lang.Long($l) => java.lang.Long.valueOf($l);
>>>>> new java.lang.Short($s) => java.lang.Short.valueOf($s);
>>>>> new java.lang.String($s) => $s :: $s instanceof java.lang.String;
>>>>>
>>>>> Float and Double constructors aren't changed because their valueOf
>>>>> implementations don't currently have caches, but they can be both
>>>>> for source consistency and to potentially take advantage of future
>>>>> runtime performance enhancements. I'd be happy to run this over
>>>>> your source base if you like, or you can install Jackpot in your
>>>>> NetBeans IDE (http://jackpot.netbeans.org), open the Refactoring
>>>>> Manager, create a new rule file, and paste in the above.
>>>>
>>>>
>>>>
>>>> works like a charm!
>>>> Jan
>>>>
>>>>> Speaking of performance enhancements, I don't recommend spending
>>>>> time trying to micro-optimize the new code. Regardless of whether
>>>>> one can write a more efficient valueOf implementation than the
>>>>> core team, HotSpot is going to optimize it for you if it becomes a
>>>>> problem. The best way to ensure that HotSpot can optimize it is
>>>>> to write clear, standard code which it can easily recognize.
>>>>> Tom
>>>>> Charlie.Hunt_at_Sun.COM wrote:
>>>>>
>>>>>> Why not write a Jackpot transformation to do all this code
>>>>>> re-engineering for you?
>>>>>> Jackpot could scan the entire GlassFish source in a matter of
>>>>>> seconds and do the entire transformation in one click. You just
>>>>>> need to write a line or two of transformation code to recognize
>>>>>> the pattern and what you want to replace it with.
>>>>>> If you talk with Tom Ball, cc'd here, I'm he would likely help
>>>>>> get someone started.
>>>>>> This Boolean and Integer transformation would be great candidates
>>>>>> to add the Jackpot transformation repository for NetBeans.
>>>>>> See http://jackpot.netbeans.org for more information on Jackpot.
>>>>>> charlie ...
>>>>>> Kin-man Chung wrote:
>>>>>>
>>>>>>> I have seen codes like new String("blah")! :-)
>>>>>>> Wonder why javac not just silently turn "new Boolean(true)" into
>>>>>>> Boolean.TRUE and "new Boolean(x)" into "x? Boolean.TRUE:
>>>>>>> Boolean.FALSE"?
>>>>>>> Also wonder if "x? Boolean.TRUE: Boolean.FALSE" may not be more
>>>>>>> efficient than Boolean.valueOf(x)?
>>>>>>> -Kin-man
>>>>>>> On Fri, 2006-10-13 at 17:13, Craig L Russell wrote:
>>>>>>>
>>>>>>>> Note that valueOf(boolean) was introduced in JDK 1.4, and many
>>>>>>>> of these are left over from previous releases.
>>>>>>>> +1 to replacing the new Boolean with valueOf.
>>>>>>>> Craig
>>>>>>>> On Oct 13, 2006, at 5:03 PM, Jan Luehe wrote:
>>>>>>>>
>>>>>>>>> I've monitored the number of java.lang.Boolean instances on
>>>>>>>>> the heap
>>>>>>>>> after different types of operations using 9.1 b21.
>>>>>>>>>
>>>>>>>>> After starting, I see approx. 1,300 instances, occupying
>>>>>>>>> approx. 21,000 bytes. Each deploy of a very simple webapp adds
>>>>>>>>> another 1,200 instances, and each undeploy adds 500.
>>>>>>>>>
>>>>>>>>> All of these instances will be gc'ed eventually, but at any time
>>>>>>>>> during the appserver lifecycle, there should be no more than
>>>>>>>>> 2 instances of java.lang.Boolean (Boolean.TRUE and Boolean.FALSE)
>>>>>>>>> on the heap.
>>>>>>>>>
>>>>>>>>> If you search the GlassFish code base, you'll find tons of places
>>>>>>>>> where "new Boolean(x)" instead of the recommended
>>>>>>>>> "Boolean.valueOf(x)"
>>>>>>>>> is used. I've also seen places where "new Boolean(true)" or
>>>>>>>>> "new Boolean("true")" is used instead of Boolean.TRUE.
>>>>>>>>>
>>>>>>>>> All of this is flagged by FindBugs (along with "new
>>>>>>>>> Integer(x)" vs
>>>>>>>>> "Integer.valueOf(x)", etc.).
>>>>>>>>>
>>>>>>>>> Fixing this is a very low-hanging fruit. We've already cleaned up
>>>>>>>>> most of the web code.
>>>>>>>>>
>>>>>>>>> Jan
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>
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