public class JavaUsEx : MonoBehaviour {
    static AndroidJavaClass jc = null;
    static AndroidJavaObject jo;
    public string cameHere  = "No...";
    // Use this for initialization    
    void Start () {
     try{
      jc = new AndroidJavaClass("MyJavaClass"); //!!!!!!

     }
     catch(Exception e)  {
      cameHere = e.Message;
     }
     try{
      jo = new AndroidJavaObject("MyJavaClass"); //!!!!!!!
     }
     catch(Exception e)  {
      cameHere = e.Message;
     }
    }
     // Update is called once per frame
    void Update () {
     if(Input.GetKeyDown(KeyCode.Escape))
      Application.Quit();
        
    }
    void OnGUI(){

     if(jo != null)
      GUI.Label(new Rect(100,100,300,300),"Not empty" + jo.Call<string>("ReturnString"));
     else
      GUI.Label(new Rect(100,100,300,300),"null yeah");
     GUI.Label(new Rect(100,200,300,300),cameHere);

    }
}