[fedora-java] Proposal to deprecate _prefer_jre

[Mikolaj Izdebski]

On 05/18/2015 10:15 AM, Jiri Vanek wrote:
> On 05/18/2015 08:29 AM, Aleksandar Kurtakov wrote:
>> ----- Original Message -----
>>> From: "Mikolaj Izdebski" <mizdebsk at redhat.com>
>>> To: "Fedora Java Development List" <java-devel at lists.fedoraproject.org>
>>> Sent: Monday, 18 May, 2015 8:07:15 AM
>>> Subject: [fedora-java] Proposal to deprecate _prefer_jre
>>>
>>> _prefer_jre is environmental variable, which once set to true causes
>>> javapackages-tools to prefer JRE over JDK when choosing JVM to use.
>>>
>>> _prefer_jre was most useful in multi-JVM scenario. For example when
>>> there was JDK 1.5 and JRE 1.7 installed, javapackages-tools would choose
>>> JDK 1.5 by default. Setting _prefer_jre=true would allow more recent JRE
>>> 1.7 to be used instead.
>>>
>>> Currently in Fedora there is only one Java implementation. Moreover,
>>> with Java 9 distinction between JDK and JRE becomes less clear.
>>> Therefore I propose to deprecate _prefer_jre environmental variable and
>>> remove it in a future release of javapackages-tools, in a year or so.
>>>
>>> Any objections or comments?
>>
>> +1 . It's not widely used and is yet another reason for unpredictability.
>>
>>
> I don't understand this effort.
> 
> With https://bugzilla.redhat.com/show_bug.cgi?id=1098508 in mind - why
> to abandon it?
> I'm not exactly  against  this proposal, but  I still have an feeling
> that there is underlying issue in java packages or in jtools.
> 
> The correct approach, if jre + sdk separation will be kept, should be:
> only jre installed - use jre
> sdk installed (jre installed as dependence) :
>   - application requires jre - use jre
>   - application rewires  devel, use jdk

There is no harm in using full SDK even if the app would work fine with
just JRE. But I'm fine with keeping existing behaviour if there are any
doubts about deprecating it.

> Now - jdk9 ... is different. Maybe something can be done better so
> jtools nor java apps suffer by above logic.

We can go furnther and avoid using alternatives at all and instead rely
on config file /etc/java/java.conf for specifying default JVM to use.
This could be considered after Java 9 is default in Fedora.

-- 
Mikolaj Izdebski
Software Engineer, Red Hat
IRC: mizdebsk