Question

I’m using android java plugin to call my java function in unity like this:

static IntPtr cls_Activity;
static IntPtr fid_Activity;
static IntPtr obj_Activity;
static IntPtr kdataActivityClass;
static IntPtr startAdsMethod;

    void Start () {
        cls_Activity = AndroidJNI.FindClass("com/unity3d/player/UnityPlayer");
        fid_Activity = AndroidJNI.GetStaticFieldID(cls_Activity, "currentActivity", "Landroid/app/Activity;");
        obj_Activity = AndroidJNI.GetStaticObjectField(cls_Activity, fid_Activity);
        kdataActivityClass = AndroidJNI.FindClass("com/kdata/unitytest/UnityUrlPlugin");
        startAdsMethod = AndroidJNI.GetMethodID(PakdataActivityClass, "getURL","()V");
        Debug.Log("obj_Activity"+obj_Activity);     
        Debug.Log("kdataActivityClass"+kdataActivityClass);     
        Debug.Log("Method"+startAdsMethod);     
            if (AndroidJNI.IsInstanceOf(obj_Activity, kdataActivityClass) != false)
            {                 
               jvalue[] myArray = new jvalue[1];
               AndroidJNI.CallStaticStringMethod(obj_Activity, startAdsMethod, myArray);
            }

The problem is that I am getting access to the class but method from the class is returns null

Debug.Log("obj_Activity"+obj_Activity); =>retuns value
Debug.Log("kdataActivityClass"+kdataActivityClass); =>returns =>value
Debug.Log("Method"+startAdsMethod); =>retunns null <=== here is the problem this method

Should return a hardcoded string but its not working in unity.

Help is highly appreciated.
Thanks

Answer 1

Check getURL method jni signature with javap (did you put the same to your third parameter ?) :

cd <pathToUnityUrlPluginClass>

javap -p -s <UnityUrlPlugin>