Re: Java version used by Jpl (Prolog to Java)

On 03/20/2014 04:01 PM, Paulo Moura wrote:
>
> On 19/03/2014, at 00:03, Sergio Castro <[email protected]> wrote:
>
>> I have just realized that the Java version used by JPL (Prolog side) is not the one configured by default.
>>
>> My installed Java version is 7, as verified with:
>>
>> $ java -version
>> java version "1.7.0_51"
>> Java(TM) SE Runtime Environment (build 1.7.0_51-b13)
>> Java HotSpot(TM) 64-Bit Server VM (build 24.51-b03, mixed mode)
>>
>> Also, the JAVA_HOME environment var is properly set.
>>
>> However, if I execute this query in swi:
>>
>> ?- jpl_call( class([java,lang],['System']), 'getProperty', ['java.version'], V).
>> V = '1.6.0_65'.
>>
>>
>> I see that it is using Java 6 instead of 7. How could I fix it so it will use the default java installation ?
>
> I can reproduce the problem with SWI-Prolog 7.1.10. But the strange thing is that in the "packages/jpl/config.log" file I have:
>
> JAR='/Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home/bin/jar'
> JAVA='/Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home/bin/java'
> JAVAC='/Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home/bin/javac'
> JAVACFLAGS='-source 1.4 -target 1.4'
> JAVADOC='/Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home/bin/javadoc'
> JAVALIBS='-Wl,-framework,JavaVM'
> JAVA_HOME='/Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home'
> JAVA_LIBRARY_PATH=''
> JAVA_PRELOAD=''
> JPLCFLAGS='-I'\''/Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home/include'\'' -I'\''/Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home/include/darwin'\'''
>
> Nevertheless, I also get:
>
> ?- jpl:jpl_call('java.lang.System',getProperty,['java.version'],_G1413)
> V = '1.6.0_65'.
>
> So, it seems that JPL is built using Java 7 but at runtime it starts (the Apple provided and installed under /System) Java 6.

I guess the final VM is decided by what is linked to libjpl.dylib.
You can find that using

	otool -L libjpl.dylib

You can change that using

	install_name_tool -change old new libjpl.dylib

Hope this helps (otherwise you need a real Apple guru).

	Cheers --- Jan