title: FindClass cannot find custom Java class
body: <p>I have a purely native app, as I use the android_native_app_glue and the entrypoint to my app is </p>
  
  <pre><code> android_main(..)
  </code></pre>
  
  <p>I also have a Java helper type class:</p>
  
  <pre><code> package abc.def.ghi
   public class MyJavaClass extends Activity
   {
        public void callback() 
        {
            Log.v(TAG, "In MyJavaClass");
        }
   }
  </code></pre>
  
  <p>I want to call the 'callback' method from native. I do so by:</p>
  
  <pre><code>jclass myClass = env-&gt;FindClass("abc/def/ghi/MyJavaClass");
  if( myClass == NULL )
      LOGI("myClass null");
  jmethodID mid = m_pEnv-&gt;GetMethodID(myClass, "callback", "()V");
  if( mid == NULL )
      LOGI("MID null");
  m_pEnv-&gt;CallVoidMethod(myClass, mid);
  </code></pre>
  
  <p>However this results in a message that myClass is null. My 'env' pointer should be okay because when I pass "android/os/build" in FindClass, it finds it, but cannot find my custom class.</p>
  
  <p>In the LOGCAT, I see:
       "JNI Warning: Can't call Labc/def/ghi; callback on instance of Ljava/Lang/Class;"</p>
  
  <p>I think this means something is wrong with the first parameter of my CallVoidMethod.
  I noticed in the other examples that most people perform their CallVoidMethod within a function with a  signature that is generated by javah, and they use the <code>obj</code> parameter in their <code>CallVoidMethod</code>: </p>
  
  <pre><code>  JNIEXPORT void JNICALL function(JNIEnv *env, jobject obj, jstring s)
  </code></pre>
  
  <p>However I cannot use this because my app's entry point is in native. </p>