This is initial Java binding implementation. For now there are supported only basic functions for running scripts and types converting.
See https://docs.julialang.org/en/stable/manual/embedding/
Class org.julia.jni.swig.Julia4J implements JNI calls to libjulia. See example
Classes from package class org.julia.scripting implement jsr233 scripting interface. See example
Example 1:
import org.julia.jni.swig.Julia4J;
Julia4J.jl_init();
Julia4J.jl_eval_string("dump(:(1 + 2x^2))");
Julia4J.jl_atexit_hook(0);Example 2:
import org.julia.jni.swig.Julia4J;
import org.julia.jni.swig.SWIGTYPE_p_jl_value_t;
import org.julia.scripting.JuliaScriptEngineFactory;
ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("julia");
// evaluate Julia code
engine.eval("dump(:(x^2 + y^2))");
Object result = engine.eval("2 ^ 10");
long checkedResult = Julia4J.jl_unbox_int64((SWIGTYPE_p_jl_value_t) result);
assertEquals(1024, checkedResult);Example 3:
import org.julia.jni.swig.Julia4J;
import org.julia.jni.swig.SWIGTYPE_p_jl_value_t;
import org.julia.scripting.JuliaScriptEngineFactory;
ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("julia");
engine.put("x", "hello");
// print global variable "x"
engine.eval("println(x);");
// the above line prints "hello"
// Now, pass a different script context
ScriptContext newContext = new SimpleScriptContext();
Bindings engineScope = newContext.getBindings(ScriptContext.ENGINE_SCOPE);
// add new variable "x" to the new engineScope
engineScope.put("x", "world");
// execute the same script - but this time pass a different script context
engine.eval("println(x);", newContext);
// the above line prints "world"
// example from https://docs.oracle.com/javase/7/docs/technotes/guides/scripting/programmer_guide/For running: julia should be installed.
For building with binaries: julia, julia-devel, Java 8, swig, gcc, make.
These sources doesn't include native binary libraries. But you can build them manually by swig/build.sh script.
Also see swig/lib_src/Makefile
Next run ./gradlew build
- automate native binaries building. For now, added CMake. Mac OS works with manual copy only due to rpath issue. Linux platform might be working but with running
make installafterbuild.shfromswig/path. And proper environment variables setup is also required both for JDK and Julia. - fix SWIG related class names like SWIGTYPE_p_jl_value_t
- implement convenient Java<->julia_JNI types converters
- implement all methods of scripting engine/factory instead of stubs
- implement direct access to functions and variable of Julia context to avoid code parsing per call
- ...