No JNI library to link to on android toolchain

Question

There seems to be "jni.h" header in the android toolchain but no library to link to.

Can somebody guide me how can I invoke Java functions from C code in my app?

Answer 1

Android does not export a JNI library. This means that there is no way in the system to call JNI_CreateJavaVM() and her ilk from user-space C code. You can create your own JVM, but it will not be the same Java, and won't have access to Android SDK classes and methods.

In Android, a Zigote process is started with a special JVM (Dalvik or ART), and then Java can load your C code (in form of .so files), not vice versa.

Your C code can use the standard JNI techniques like CallVoidMethod() and her kin to invoke Java methods. Note that Android SDK Java methods often need some 'handles', like context , to have their work done; usually, you must rely on some calls from Java to C that will give you these handles.