mraajava.i: Initialize mraa when library is loaded by the JVM

Signed-off-by: Petre Eftime <petre.p.eftime@intel.com>
Signed-off-by: Andrei Vasiliu <andrei.vasiliu@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

src/java/mraajava.i

@@ -46,7 +46,7 @@ namespace mraa {
 class Spi;
 %typemap(out) uint8_t*
 {
-  // need to loop over length
+  /* need to loop over length */
   $result = JCALL1(NewByteArray, jenv, arg3);
   JCALL4(SetByteArrayRegion, jenv, $result, 0, arg3, (jbyte *) $1);
   free($1);
@@ -55,3 +55,11 @@ class Spi;
 
 %feature("director") IsrCallback;
 %include ../mraa.i
+
+%wrapper %{
+    jint JNI_OnLoad(JavaVM *vm, void *reserved) {
+        /* initialize mraa */
+        mraa_init();
+        return JNI_VERSION_1_8;
+    }
+%}