RFR: JDK-8242629 Remove references to deprecated java.util.Observer and Observable

[Magnus Ihse Bursie]

On 2020-04-14 14:44, coleen.phillimore at oracle.com wrote:
>
> This looks good to me since we can't remove this. 
Thanks for your review!

Does jdk.hotspot.agent follow the Hotspot review rules requiring two 
Reviewers?
> The patch complains that for your Observer.java:
>
> \ No newline at end of file
Yeah, I just noticed that. :-( I'll fix that before pushing.

/Magnus

>
> Thanks,
> Coleen
>
> On 4/14/20 7:04 AM, Magnus Ihse Bursie wrote:
>> As a first step towards fixing deprecation warnings in SA, all the 
>> references (200+) to the deprecated java.util.Observer and Observable 
>> needs to be fixed, otherwise all other changes will drown in this one.
>>
>> This solution is the result of the preceding discussions in 
>> serviceability-dev. That means that most of the change consists of 
>> adding an explicit import like this:
>>
>> import sun.jvm.hotspot.utilities.Observable;
>> import sun.jvm.hotspot.utilities.Observer;
>>
>> to override the general java.util.* import that was already present 
>> in all (or almost all) files, and make 
>> sun.jvm.hotspot.utilities.Observable and Observer extend the 
>> java.util versions but with deprecation warnings disabled.
>>
>> It turned out however, that this simplest approach did not work 
>> fully. Since the interface java.util.Observer had the single method 
>> "void update(java.util.Observable o, Object arg)" it did not help to 
>> create a new interface sun.jvm.hotspot.utilities.Observer that 
>> extended java.util.Observer. I did not observe this issue in my PoC 
>> webrev that I posted during the discussion. :-(
>>
>> Instead, for Observer, I had just created a new interface with the 
>> same method, but that uses sun.jvm.hotspot.utilities.Observable 
>> instead of java.util.Observable.
>>
>> The end effect is the same -- the only change needed to most files is 
>> an added import, we get rid of the deprecation warnings, and we did 
>> not have to copy any significant amount of code from java.util.
>>
>> I now hope this is acceptable by all.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8242629
>> WebRev: 
>> http://cr.openjdk.java.net/~ihse/JDK-8242629-fix-SA-Observer/webrev.01
>>
>> (When reading the patch, I recommend looking at the patch file 
>> http://cr.openjdk.java.net/~ihse/JDK-8242629-fix-SA-Observer/webrev.01/open.patch 
>> instead of individually checking the files in the webrev.)
>>
>> /Magnus
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.openjdk.java.net/pipermail/serviceability-dev/attachments/20200414/9eaaff89/attachment.htm>