Hi. You need add #[link(name = "android")]

[Z1W3]

#[link(name = "android")] // add this
extern "C" {
    pub fn AAssetManager_fromJava(env: *mut JNIEnv, assetManager: jobject) -> *mut AAssetManager;
}

[azw413]

I need this too, can't instantiate an AssetManager from java instance otherwise. This is essential if you have a Java application in addition to a native lib i.e. not a purely native activity.