Test project to investigate building a java project with native JNI code.
Compiler settings are MinGW windows centric.
- 32 bit java JDK (Java 7)
somewhat recent version of mingw on the path
- Set JAVA_HOME to point at a 32 bit JDK (Java 7)
- Add the mingw bin directory to your path (set PATH=%PATH%;C:\MinGW\bin)
- gradlew build
- %JAVA_HOME%\bin\java -jar build\libs\GradleJNI-1.0.jar
Note: a trick is used to store the DLL inside the jar. Before the native library is loaded it is extracted from the jar to a temporary location then loaded from there. With OSGi you'd get that for free.
Note2: This is not intended to be nice java/C++ code. Just enough to investigate the in's and out's of building this with gradle.
TODO: change to multi project build:
: java builds jar & C++ artifact with JNIFoo.h generated with javah :native builds DLL/so for an architecture, has dependency on artifact with JNIFoo.h creates native artifact for the DLL/so :release-jar grabs available DLL/so's and jar and bundles it to one release-jar that can be deployed and run on multiple architectures
On a local machine this should depend on each other in the right way and build just for the native architecture.
In CI one would
- trigger the java build & block native builds
- run native builds in parallel
- after the above run release-jar gathering all bits
TODO investigate cross compiling with mingw32/mingw64 compiler on linux