[Engine-devel] java 1.6 compatibility no more?

Thu Jul 19 12:19:06 UTC 2012

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…

> 
> 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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