Support for JNI 1.8

[FransM22]

JavaCall causes an error when using it with JNI versions later than 1.6. The error displayed is ERROR: assertion failed: jni_version == JNI_VERSION_1_6. Since JDK 1.8, JNI version 1.8 is included, making this assertion always fail when using JavaCall on *.jar files created with this version of Java.

Line 457 In src/JavaCall.jl (@assert ccall(jnifunc.GetVersion, Cint, (Ptr{JNIEnv},), penv) == JNI_VERSION_1_6) causes the error.

Changing the line to @assert jni_version >= JNI_VERSION_1_6 #Also allowing jni 1.8 solves the issue. I can't find any changes since 1.6, and after a little testing, using JNI 1.8 seems to be working fine.

[aviks]

Well, it looks like Oracle have changed the API version without documenting the change. The JDK8 docs still mention 1_6 as the latest available JNI version. http://docs.oracle.com/javase/8/docs/technotes/guides/jni/spec/functions.html#version_information

I am therefore hesitant to claim support in JavaCall for something that is so underspecified. There have been some reports of crashes with JDK8. eg #6. Can you try retrieving an exception in JDK8 (just throw an exception in any code that you call via JavaCall) and see what happens?

[aviks]

JavaCall.jl now does work on 1.8. The assertion checking for 1.7 has been removed. In Linux, there are no reported issues due to 1.8. In OSX however, there are some spurious segfaults when moving from 1.7 to 1.8

[aviks]

Everything should be fixed in JavaCall 0.2.3 onwards. Note that on OSX, there are messages printed to console about segfaults, but they are harmless, and are due to the interaction of Java and Julia's signal handlers. In julia 0.4 run with --handle-signals=no (but that might disable ctrl-C)

Please let me know if there are any further issues.