Error when build JNI - post facebook

Hi all,
I’m trying to post score to facebook using cocos2d-x. I found a sample here: https://github.com/Piperoman/CCSocialNetwork. But when i try to build it, something wrongs. In class InterfaceJNI , i built it and it has an error in line: +“JavaVM* jvm = JniHelper::getJavaVM();+” : “error LNK2019: unresolved external symbol …”. Have anyone have a solution to settle this error?

JniHelper is part of cocos2d-x.
Have you linked it?

Maybe the reason due to the error configuration of my project. Though it has the macro #if
#include “InterfaceJNI.h”
, but when build in Win32, class InterfaceJNI is built . I think that’s why i have an error when built in win32. But when i built with Android project: build_native.sh, it build successful.