[Lift] Have we (finally) left java 6 behind ?

[Peter Petersson]

Hi

I accidentally compiled a Lift 3 app having java setting pointing to
java 6 and got the (in)famous

java.lang.UnsupportedClassVersionError: net/liftweb/util/BCrypt : Unsupported major.minor version 51.0

when posting a user registration form in a lift starter template.

I know we use java 7 for Lift 3 (hence the error above) but I am still
unsure about Lift 2.6.2 so I'm throwing out the question here.

Have we finally left java 6 behind ?

best regards Peter Petersson

[Andreas Joseph Krogh]

Don't know, but hope so.

 

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[Matt Farmer]

Pretty sure the 2.6.x series still supports Java 6. 3.0 drops it.

—
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[Antonio Salazar Cardozo]

Do we have a reason we're dropping Java 6? As in, is there a limitation we're trying to

get around? Or is it simply a build choice? Just wondering. If it's not hard for us to support

Java 6 I'd say it would be a Good Thing™—Scala 2.11 supports it, as far as I understand.

Thanks,

Antonio

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[Matt Farmer]

Couldn’t tell you. I just remember having a discussion that 3.0 didn’t have to support Java 6 anymore. If that’s wrong then we’ve already screwed up. heh. I do recall it being a PITA to compile correctly for on Mac machines, which a lot of us use. I would have suggested it’s so we can Scala 2.12 cross-compile, but it looks like they decided to skip directly to Java 8?!

—
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[Antonio Salazar Cardozo]

Yikes, so they have. Looks like we'll be cross-compiling Lift 3 almost before it's out of

the cradle heh.

Thanks,

Antonio

[Andreas Joseph Krogh]

På torsdag 06. august 2015 kl. 05:04:28, skrev Antonio Salazar Cardozo <savedf...@gmail.com>:

Yikes, so they have. Looks like we'll be cross-compiling Lift 3 almost before it's out of

the cradle heh.

Thanks,

Antonio

 

FWIW I think supporting anything below java-1.8 is crazy as it produces much fewer .class-files when compiling for java-1.8 closures. I'm using 2.11.7 with java-8-compat and with the compiler-options -Ydelambdafy:method -Ybackend:GenBCode -target:jvm-1.8 and now our projects contains ~9K classes compared to ~50K classes. Compilation also is faster. When using runtime-weaving (aspectj) the weaving-process is also much faster.

 

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[Peter Petersson]

I guess there are no really good reasons for dropping java 6 for the 2.6 series and as Mat pointed out the may be a lot of Mac users still on java 6.
 
The motivation for dropping it could be:
-- Avoiding occasional compilation mistakes with mixing java 6 and 7 jars resulting in the error I showed in the starting post
-- Avoiding the complication in the build systems (if you mix in java in your code).

But supporting java 6 users as they may be plenty still on Mac (supposedly) and the fact that we are going to have to deal with java 8 soon enough leaves only one somehow week motivation, I guess we have to live with it ;)

best regards Peter Petersson

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[Matt Farmer]

Peter,

I’m afraid you misunderstood my message.

Most Mac users are on Java 7 or 8 now, I believe. What I meant was that compiling the Framework for Java 6 is annoying on a Mac because before Java 7 Apple was issuing their own version of Java and you have to figure out how to install that, get it working, etc. Setting the target version via compiler flags doesn’t work. This was such a pain that the one time I ran release I finally caved and provisioned a VM on Linode.

So, I’m +1 on dropping Java 6, personally.

—
Matt Farmer | Blog | Twitter

[Antonio Salazar Cardozo]

The counterargument is that many shops may still be running Java 6 on their servers. However,

Oracle stopped support for Java 6 in 2013, so I think we're fine to drop support. Much like with

Oracle, if folks need custom support, there's the option of paying a committer to do the work

needed for that.

Java 7 is EOL as of April of this year, so I think I'm +1 on not supporting it in Lift 3. Whatever

we support when Lift 3 goes out, we should probably continue to support through a hypothetical

Lift 4 release unless something significant occurs, IMO.

Thanks,

Antonio

[Joe Barnes]

I'm in the camp of letting JDK 6 work if it isn't painful, but if it's painful then we have plenty of reason to drop it (Oracle's EOL in particular).  

So, why doesn't it support JDK 6 for free, regardless of the JDK you run sbt with?  I thought that Scala 2.11 (sans compiler options Andreas has mentioned) emits JDK 6-compatible code.  

Joe

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[Antonio Salazar Cardozo]

I think it's the small amount of Java code we have in the codebase. Maybe we can flag javac

differently? I really can't remember for sure though >_>

Thanks,

Antonio

[Joe Barnes]

You mean like this?

javacOptions ++= Seq("-source", "1.6")

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[Peter Petersson]

On 08/10/2015 02:47 PM, Joe Barnes wrote:

You mean like this?

javacOptions ++= Seq("-source", "1.6")

I have a vague recollection that this is not enough, I think a answer related to this is on the ml somewhere.
best regards Peter

[Peter Petersson]

... It's getting vaguer (can't find it)

best regards Peter

[Joe Barnes]

That's interesting. We hit this at work one time. Someone built our application with JDK8 and tried to deploy it in ElasticBeanstalk running JDK7.  Adding the javacOptions to our build.sbt did the trick.  I'm quite curious to know what else could go wrong here.

Joe

[Andreas Joseph Krogh]

På mandag 10. august 2015 kl. 14:47:45, skrev Joe Barnes <barn...@gmail.com>:

You mean like this?

javacOptions ++= Seq("-source", "1.6")

 

Isn't ("-target", "1.6") what we want here, to produce 1.6 class-files?

 

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[Robert Marcano]

On 08/10/2015 11:25 AM, Andreas Joseph Krogh wrote:

På mandag 10. august 2015 kl. 14:47:45, skrev Joe Barnes <barn...@gmail.com>:

You mean like this?

javacOptions ++= Seq("-source", "1.6")

 

Isn't ("-target", "1.6") what we want here, to produce 1.6 class-files?

Yes "-target" is needed for bytecode level, -source provides source compatibility, some old Java code doesn't compile on new source levels. Use both arguments

 

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and...@visena.com

www.visena.com

 

[Peter Brant]

I don't think that's sufficient if we want to actually support 1.6. It will still compile against the standard library of whatever you're using to do the compile. We could inadvertently end up using a method that wasn't added until later with a resulting runtime error for somebody actually using 1.6.

Pete

[Matt Farmer]

Diego was the last person to try doing that and we actually had a bad release of Lift in the 2.5 series at one point that resulted from his attempts. We ended up with most things being compiled correctly, but random class files were compiled to the original target. Probably something to do with how our project structure is designed and how sbt manages those settings.

Also only vaguely remember.

But I do know that I was advised to provision a server with Java 6 on it to actually build the artifacts. Which is what I’ve done whenever I run release.

—
Matt Farmer | Blog | Twitter

On Aug 10, 2015, at 12:22 PM, Peter Brant <peter...@gmail.com> wrote:

I don't think that's sufficient if we want to actually support 1.6. It will still compile against the standard library of whatever you're using to do the compile. We could inadvertently end up using a method that wasn't added until later with a resulting runtime error for somebody actually using 1.6.

Pete

On Mon, Aug 10, 2015 at 6:14 PM, Robert Marcano <rob...@marcanoonline.com> wrote:

On 08/10/2015 11:25 AM, Andreas Joseph Krogh wrote:

På mandag 10. august 2015 kl. 14:47:45, skrev Joe Barnes <barn...@gmail.com>:

You mean like this?

javacOptions ++= Seq("-source", "1.6")

 

Isn't ("-target", "1.6") what we want here, to produce 1.6 class-files?

Yes "-target" is needed for bytecode level, -source provides source compatibility, some old Java code doesn't compile on new source levels. Use both arguments

--

Andreas Joseph Krogh

CTO / Partner - Visena AS

Mobile: +47 909 56 963

and...@visena.com

www.visena.com

<Mail Attachment.png>

[Robert Marcano]

On 08/10/2015 11:52 AM, Peter Brant wrote:
> I don't think that's sufficient if we want to actually support 1.6. It
> will still compile against the standard library of whatever you're using
> to do the compile. We could inadvertently end up using a method that
> wasn't added until later with a resulting runtime error for somebody
> actually using 1.6.

True, javac gives a warning about adding the correct classpath when you
run it that way, but if the Lift committer team want to support Java 6,
build and tests will need to be run on a Java 6 JVM, more work I don't
know if they want it.

The -source and -target options assure the bytecode is correct, only
building and testing with the old JVM can assure compatibility. Is like
using reflection to use Java 8 APIs and compiling with a Java 6 JVM, it
will compile, but compatibility with Java 6 is only guaranteed if test
validates the reflection code is only run on Java 8 for example.

>
> Pete
>
> On Mon, Aug 10, 2015 at 6:14 PM, Robert Marcano
> <rob...@marcanoonline.com <mailto:rob...@marcanoonline.com>> wrote:
>
> On 08/10/2015 11:25 AM, Andreas Joseph Krogh wrote:
>> På mandag 10. august 2015 kl. 14:47:45, skrev Joe Barnes

>> <<mailto:barn...@gmail.com>barn...@gmail.com
>> <mailto:barn...@gmail.com>>:
>>
>> You mean like this?
>>
>> |javacOptions ++=Seq("-source","1.6")|

>>
>> Isn't ("-target", "1.6") what we want here, to produce 1.6
>> class-files?
>
> Yes "-target" is needed for bytecode level, -source provides source
> compatibility, some old Java code doesn't compile on new source
> levels. Use both arguments
>
>> --

>> *Andreas Joseph Krogh*

>> CTO / Partner - Visena AS

>> Mobile: +47 909 56 963 <tel:%2B47%20909%2056%20963>
>> and...@visena.com <mailto:and...@visena.com>
>> www.visena.com <https://www.visena.com>
>> <https://www.visena.com>

>> --
>> --
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>> <http://liftweb.net>http://liftweb.net

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>>
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[Peter Petersson]

On 08/10/2015 10:45 PM, Robert Marcano wrote:
> On 08/10/2015 11:52 AM, Peter Brant wrote:
>> I don't think that's sufficient if we want to actually support 1.6. It
>> will still compile against the standard library of whatever you're using
>> to do the compile. We could inadvertently end up using a method that
>> wasn't added until later with a resulting runtime error for somebody
>> actually using 1.6.
>
> True, javac gives a warning about adding the correct classpath when
> you run it that way, but if the Lift committer team want to support
> Java 6, build and tests will need to be run on a Java 6 JVM, more work
> I don't know if they want it.
>
> The -source and -target options assure the bytecode is correct, only
> building and testing with the old JVM can assure compatibility. Is
> like using reflection to use Java 8 APIs and compiling with a Java 6
> JVM, it will compile, but compatibility with Java 6 is only guaranteed
> if test validates the reflection code is only run on Java 8 for example.
>

Thanks Robert this was what I was looking for when I said it was not
enough before.

I pretty sure that the current way of building 2.6.x is using the actual
Java 6 jvm/jdk. As I recall there was a try to simplify the cross build
stuff but I think that what you just pointed out was the thing that made
us keep the current setup.

best regards Peter Petersson

[Diego Medina]

sorry I missed this thread, I think someone already said this but using the flags to build lift using java isn't enough, you have to have the jvm6 and/or the source files for java 6 to actually build it correctly. It was going to be a real pain, and considering java 6 was EOL, we decided lift 3 breaking changes was going to include only building for java 7.

We are not building any more lift 2.6 releases, unless anyone finds a really horrible security bug on lift 2.6, which means lift 2.6 is the last Lift release that supports java 6.

I'm all for only supporting java 8 on lift 3.0 if timing works out.

Thanks

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http://blog.fmpwizard.com/

[Matt Farmer]

So, should we start an up/down +1/-1 vote on dropping Java 7 support in Lift 3?

It sounds like we’re currently at +3 / -0, with myself, Antonio, and Diego in favor.

—
Matt Farmer | Blog | Twitter

[Joe Barnes]

The original 2.12 Roadmap has it's final release targeting January 2016.  I'm in favor of going further and waiting to release Lift 3.0 in that time frame only targeting Scala 2.12/jdk8

Joe

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[Matt Farmer]

I am not in favor of that, tbh.

Scala 2.11 has been out long enough that I think it’s O.K. to start expecting libraries and applications to support it. I also think it’s good to provide some scala version overlap between 2.6 and 3.0. We’ll want to start cross building as soon as 2.12 comes out, but let’s not add additional pain onto the Lift 3 upgrade by requiring two Scala version jumps.

My 0.02.

—
Matt Farmer | Blog | Twitter

[Antonio Salazar Cardozo]

Agree. I'd like to get Lift 3 out by the end of the year or early next if we can, and I

think if we were to go 2.12 only I wouldn't be comfortable unless we waited another

quarter or two to make sure any 2.12 language/lib issues were shaken out.

Thanks,

Antonio

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[Andreas Joseph Krogh]

På mandag 17. august 2015 kl. 16:36:11, skrev Matt Farmer <ma...@frmr.me>:

So, should we start an up/down +1/-1 vote on dropping Java 7 support in Lift 3?

 

It sounds like we’re currently at +3 / -0, with myself, Antonio, and Diego in favor.

 

+1 for dropping jdk7 for Lift3

 

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[Vasya Novikov]

I'd vote to keep java7 compatibility if that does not mean lots of
additional work.

In particular, I do not even have java8 in my package manager. Both
Debian-stable and Ubuntu-LTS only have the 6 and 7 versions.

https://www.debian.org/distrib/packages
http://packages.ubuntu.com/

On 2015-08-17 18:37, Matt Farmer wrote:
> I am not in favor of that, tbh.
>
> Scala 2.11 has been out long enough that I think it’s O.K. to start expecting libraries and applications to support it. I also think it’s good to provide some scala version overlap between 2.6 and 3.0. We’ll want to start cross building as soon as 2.12 comes out, but let’s not add additional pain onto the Lift 3 upgrade by requiring two Scala version jumps.
>
> My 0.02.
>
> —

> Matt Farmer | Blog <http://farmdawgnation.com/> | Twitter <http://twitter.com/farmdawgnation>

>> On Aug 17, 2015, at 12:09 PM, Joe Barnes <barn...@gmail.com> wrote:
>>

>> The original 2.12 Roadmap <http://www.scala-lang.org/news/2.12-roadmap> has it's final release targeting January 2016. I'm in favor of going further and waiting to release Lift 3.0 in that time frame only targeting Scala 2.12/jdk8

>>
>> Joe
>>
>>
>> On Mon, Aug 17, 2015 at 9:36 AM, Matt Farmer <ma...@frmr.me <mailto:ma...@frmr.me>> wrote:
>> So, should we start an up/down +1/-1 vote on dropping Java 7 support in Lift 3?
>>
>> It sounds like we’re currently at +3 / -0, with myself, Antonio, and Diego in favor.
>>
>> —

>> Matt Farmer | Blog <http://farmdawgnation.com/> | Twitter <http://twitter.com/farmdawgnation>

>>
>>> On Aug 16, 2015, at 1:58 PM, Diego Medina <di...@fmpwizard.com <mailto:di...@fmpwizard.com>> wrote:
>>>
>>> sorry I missed this thread, I think someone already said this but using the flags to build lift using java isn't enough, you have to have the jvm6 and/or the source files for java 6 to actually build it correctly. It was going to be a real pain, and considering java 6 was EOL, we decided lift 3 breaking changes was going to include only building for java 7.
>>>
>>> We are not building any more lift 2.6 releases, unless anyone finds a really horrible security bug on lift 2.6, which means lift 2.6 is the last Lift release that supports java 6.
>>>
>>> I'm all for only supporting java 8 on lift 3.0 if timing works out.
>>>
>>> Thanks
>>>
>>>
>>>
>>> On Tue, Aug 11, 2015 at 3:30 AM, Peter Petersson <peterss...@gmail.com <mailto:peterss...@gmail.com>> wrote:
>>> On 08/10/2015 10:45 PM, Robert Marcano wrote:
>>> On 08/10/2015 11:52 AM, Peter Brant wrote:
>>> I don't think that's sufficient if we want to actually support 1.6. It
>>> will still compile against the standard library of whatever you're using
>>> to do the compile. We could inadvertently end up using a method that
>>> wasn't added until later with a resulting runtime error for somebody
>>> actually using 1.6.
>>>
>>> True, javac gives a warning about adding the correct classpath when you run it that way, but if the Lift committer team want to support Java 6, build and tests will need to be run on a Java 6 JVM, more work I don't know if they want it.
>>>
>>> The -source and -target options assure the bytecode is correct, only building and testing with the old JVM can assure compatibility. Is like using reflection to use Java 8 APIs and compiling with a Java 6 JVM, it will compile, but compatibility with Java 6 is only guaranteed if test validates the reflection code is only run on Java 8 for example.
>>>
>>>
>>> Thanks Robert this was what I was looking for when I said it was not enough before.
>>>
>>> I pretty sure that the current way of building 2.6.x is using the actual Java 6 jvm/jdk. As I recall there was a try to simplify the cross build stuff but I think that what you just pointed out was the thing that made us keep the current setup.
>>>
>>> best regards Peter Petersson
>>>
>>>
>>>
>>> Pete
>>>
>>> On Mon, Aug 10, 2015 at 6:14 PM, Robert Marcano
>>> <rob...@marcanoonline.com <mailto:rob...@marcanoonline.com> <mailto:rob...@marcanoonline.com <mailto:rob...@marcanoonline.com>>> wrote:
>>>
>>> On 08/10/2015 11:25 AM, Andreas Joseph Krogh wrote:
>>> På mandag 10. august 2015 kl. 14:47:45, skrev Joe Barnes

>>> <<mailto:barn...@gmail.com <mailto:barn...@gmail.com>>barn...@gmail.com <mailto:barn...@gmail.com>
>>> <mailto:barn...@gmail.com <mailto:barn...@gmail.com>>>:

>>>
>>> You mean like this?
>>>
>>> |javacOptions ++=Seq("-source","1.6")|
>>>
>>> Isn't ("-target", "1.6") what we want here, to produce 1.6
>>> class-files?
>>>
>>> Yes "-target" is needed for bytecode level, -source provides source
>>> compatibility, some old Java code doesn't compile on new source
>>> levels. Use both arguments
>>>
>>> --
>>> *Andreas Joseph Krogh*
>>> CTO / Partner - Visena AS

>>> Mobile: +47 909 56 963 <tel:%2B47%20909%2056%20963> <tel:%2B47%20909%2056%20963>
>>> and...@visena.com <mailto:and...@visena.com> <mailto:and...@visena.com <mailto:and...@visena.com>>
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>>> <https://www.visena.com <https://www.visena.com/>>

>>> --
>>> --
>>> Lift, the simply functional web framework:

>>> <http://liftweb.net <http://liftweb.net/>>http://liftweb.net <http://liftweb.net/>
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>>>
>>> --
>>> --
>>> Lift, the simply functional web framework: http://liftweb.net <http://liftweb.net/>
>>> Code: http://github.com/lift <http://github.com/lift>
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>>>
>>>
>>> --
>>> --
>>> Lift, the simply functional web framework: http://liftweb.net <http://liftweb.net/>
>>> Code: http://github.com/lift <http://github.com/lift>
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>>> Stuck? Help us help you: https://www.assembla.com/wiki/show/liftweb/Posting_example_code <https://www.assembla.com/wiki/show/liftweb/Posting_example_code>

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>>>
>>>
>>>
>>> --
>>> Diego Medina
>>> Lift/Scala consultant

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>>> http://blog.fmpwizard.com/ <http://blog.fmpwizard.com/>
>>>
>>> --
>>> --
>>> Lift, the simply functional web framework: http://liftweb.net <http://liftweb.net/>
>>> Code: http://github.com/lift <http://github.com/lift>
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>>> Stuck? Help us help you: https://www.assembla.com/wiki/show/liftweb/Posting_example_code <https://www.assembla.com/wiki/show/liftweb/Posting_example_code>

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>>
>>
>> --
>> --
>> Lift, the simply functional web framework: http://liftweb.net <http://liftweb.net/>
>> Code: http://github.com/lift <http://github.com/lift>
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>> Stuck? Help us help you: https://www.assembla.com/wiki/show/liftweb/Posting_example_code <https://www.assembla.com/wiki/show/liftweb/Posting_example_code>

>>
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>>
>>
>> --
>> --
>> Lift, the simply functional web framework: http://liftweb.net <http://liftweb.net/>
>> Code: http://github.com/lift <http://github.com/lift>
>> Discussion: http://groups.google.com/group/liftweb <http://groups.google.com/group/liftweb>
>> Stuck? Help us help you: https://www.assembla.com/wiki/show/liftweb/Posting_example_code <https://www.assembla.com/wiki/show/liftweb/Posting_example_code>

>>
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>

--
Vasya Novikov

[Andreas Joseph Krogh]

På mandag 31. august 2015 kl. 19:35:27, skrev Vasya Novikov <n1m5-goo...@yandex.ru>:

I'd vote to keep java7 compatibility if that does not mean lots of
additional work.

In particular, I do not even have java8 in my package manager. Both
Debian-stable and Ubuntu-LTS only have the 6 and 7 versions.

https://www.debian.org/distrib/packages
http://packages.ubuntu.com/

 

I don't think what ships with the distro should count, that would be like excluding Windows (AFAIK JAVA doesn't ship with Windows).

Luckily there exist installers, for Windows, Ubuntu/Debian and almos any other wildly used OS, which makes java8 available.

 

add-apt-repository ppa:webupd8team/java
apt-get update
apt-get install oracle-java8-installer

 

--

Andreas Joseph Krogh

CTO / Partner - Visena AS

Mobile: +47 909 56 963

and...@visena.com

www.visena.com