[Engine-devel] java 1.6 compatibility no more?

Ayal Baron abaron at redhat.com
Thu Jul 19 12:34:00 UTC 2012 


----- Original Message -----
> 
> On Jul 19, 2012, at 14:14 , Livnat Peer wrote:
> 
> > On 19/07/12 14:41, Juan Hernandez wrote:
> >> On 07/19/2012 01:39 PM, Yair Zaslavsky wrote:
> >>> On 07/19/2012 02:31 PM, Vojtech Szocs wrote:
> >>>>> Don't we need that (the source part) to avoid Java 7 syntax in
> >>>>> GWT code?
> >>>> 
> >>>> That's a very good point.
> >>>> 
> >>>> In general, GWT compiler supports Java 5 syntax (note that there
> >>>> are no language changes between Java 5 and 6). For this reason,
> >>>> our frontend code should be compliant with Java 5. If someone
> >>>> uses new Java 7 language features in frontend code, GWT
> >>>> compiler will throw an error and the build will fail.
> >>>> 
> >>>> So the 'Java 5 only' limitation applies to frontend code and any
> >>>> other code (e.g. shared modules) that is directly referenced by
> >>>> frontend code. This shouldn't affect the backend, however.
> >>>> 
> >>>> We could do something like this:
> >>>> 
> >>>> - let oVirt root POM declare source and target compliance to
> >>>> Java 7
> >>>> - let frontend modules POM (frontend/webadmin/modules/pom.xml)
> >>>> declare source compliance to Java 5 (or 6)
> >>>> 
> >>>> (note that target compliance can be left to Java 7 since
> >>>> frontend compilation results in JavaScript code)
> >>>> 
> >>>> What do you think?
> >>>> 
> >>>> Vojtech
> >>> 
> >>> +1 - I really like this idea!
> >> 
> >> +1 from me as well.
> > 
> > 
> > There are two calls to make when it comes to JDK7 (regardless of
> > GWT -
> > excuse me for taking this discussion some steps backwards)
> > 
> > 1. Are we running with JRE 7?
> > The answer is yes we agreed on that a few months ago.
> > 
> > 2. Are we using code syntax which is incompatible with JDK6?
> > 
> > I think the answer to the above should be no (at least for now -
> > maybe
> > until the next ovirt release?).
> +1
> exactly. Why starting with jdk6 incompatible constructs unless there
> is a good (or at least any) reason for them…

+1

> 
> > 
> > There are two reason off the top of my head for that -
> > If we find an issue it is easier to compare the issue on JDK6 vs.
> > JDK7
> > if the code compiles on both.
> > 
> > Open JDK7 is out for a year or so, It was packaged for fedora only
> > in
> > March  2012, I am not sure how ofter it is used in 'production'
> > environment, I think we should at least keep ourself the option to
> > roll-back in case we need it.
> > 
> > 
> > Livnat
> > 
> > 
> > 
> >> 
> >>>> ----- Original Message -----
> >>>> From: "Juan Hernandez" <jhernand at redhat.com>
> >>>> To: "Vojtech Szocs" <vszocs at redhat.com>
> >>>> Cc: "Yair Zaslavsky" <yzaslavs at redhat.com>,
> >>>> engine-devel at ovirt.org
> >>>> Sent: Thursday, July 19, 2012 11:01:00 AM
> >>>> Subject: Re: [Engine-devel] java 1.6 compatibility no more?
> >>>> 
> >>>> On 07/19/2012 10:09 AM, Vojtech Szocs wrote:
> >>>>>> As I previously emailed - JDK7 already fixed a known issue
> >>>>>> with ldap and
> >>>>>> DNS ,and made one of my patches at gerrit redundant.
> >>>>>> Why not enjoy the bug fixes?
> >>>>> 
> >>>>> I agree, but in that case, why not switch to '1.7' Java
> >>>>> source/target compliance for oVirt Maven build as well?
> >>>>> 
> >>>>> If JDK6 cannot be used for building oVirt (because of missing
> >>>>> Java 7 APIs, because of LDAP/DNS issues in JDK6, etc.), we
> >>>>> should also update our Maven POM files. Currently, when I
> >>>>> import oVirt projects into Eclipse (using Eclipse Maven
> >>>>> plugin), I'm getting compile errors on 'bll' project. This is
> >>>>> because our Maven POM files declare '1.6' Java source/target
> >>>>> compliance.
> >>>>> 
> >>>>> Juan - you are right, but for me, it sounds quite strange to
> >>>>> have '1.6' Java source/target compliance for Maven build, and
> >>>>> use JDK7 to do the build.
> >>>> 
> >>>> Don't we need that (the source part) to avoid Java 7 syntax in
> >>>> GWT code?
> >>>> 
> >>>>> ----- Original Message -----
> >>>>> From: "Yair Zaslavsky" <yzaslavs at redhat.com>
> >>>>> To: engine-devel at ovirt.org
> >>>>> Sent: Thursday, July 19, 2012 7:59:45 AM
> >>>>> Subject: Re: [Engine-devel] java 1.6 compatibility no more?
> >>>>> 
> >>>>> On 07/18/2012 08:21 PM, Juan Hernandez wrote:
> >>>>>> On 07/18/2012 06:33 PM, Vojtech Szocs wrote:
> >>>>>>> In fact, for both backend and frontend, Maven effective POM
> >>>>>>> contains:
> >>>>>>> 
> >>>>>>> <artifactId>maven-compiler-plugin</artifactId>
> >>>>>>> <configuration>
> >>>>>>>  <source>1.6</source>
> >>>>>>>  <target>1.6</target>
> >>>>>>> </configuration>
> >>>>>>> 
> >>>>>>> Therefore, according to Maven POM files, oVirt should be
> >>>>>>> build-able using Java 6, but it's not. (?)
> >>>>>> 
> >>>>>> These maven settings just tell the java compiler to accept
> >>>>>> Java 6 syntax
> >>>>>> only and to generate a Java 6 compatible .class file format,
> >>>>>> but they
> >>>>>> don't restrict the set of APIs that can be used.
> >>>>>> 
> >>>>>>> The problem is in backend/manager/modules/bll:
> >>>>>>> StorageDomainCommandBase class uses new Java 7
> >>>>>>> Long.compare() static method.
> >>>>>>> 
> >>>>>>> I think we should decide if we want to be compliant with Java
> >>>>>>> 7, or submit a patch that uses Java 6 API (Long.compareTo
> >>>>>>> instance method).
> >>>>>>> 
> >>>>>>> Vojtech
> >>>>> 
> >>>>> As I previously emailed - JDK7 already fixed a known issue with
> >>>>> ldap and
> >>>>> DNS ,and made one of my patches at gerrit redundant.
> >>>>> Why not enjoy the bug fixes?
> >>>>> 
> >>>>>>> 
> >>>>>>> 
> >>>>>>> ----- Original Message -----
> >>>>>>> From: "Laszlo Hornyak" <lhornyak at redhat.com>
> >>>>>>> To: "engine-devel" <engine-devel at ovirt.org>
> >>>>>>> Cc: "Vojtech Szocs" <vszocs at redhat.com>
> >>>>>>> Sent: Wednesday, July 18, 2012 5:43:34 PM
> >>>>>>> Subject: java 1.6 compatibility no more?
> >>>>>>> 
> >>>>>>> Hi,
> >>>>>>> 
> >>>>>>> It may be a historic moment, but for a few hours oVirt engine
> >>>>>>> is no longer building on java 1.6.
> >>>>>>> Is this intentional?
> >>>>>>> 
> >>>>>>> Laszlo
> >> 
> >> 
> > 
> > 
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> 
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