Integrate Eclipse and Unity

Hi; I wanna integrate unity with Eclipse, so in Unity i write this script:

using UnityEngine; using System.Collections;

public class Test : MonoBehaviour {

void OnGUI() {

if(GUI.Button(new Rect(20,70,80,20), "Call Android Method"))

{

 using (AndroidJavaClass cls_UnityPlayer = new AndroidJavaClass("com.unity.eclipse")) 

 {

     using (AndroidJavaObject obj_Activity = cls_UnityPlayer.GetStatic<AndroidJavaObject>("MainActivity")) 

     {

         obj_Activity .CallStatic("foo");

     }

 }
 }

}

and in Eclipse i create an android Applicatio and create a MainActivity.java in which i write this:

package com.unity.eclipse;

import com.unity3d.player.UnityPlayerActivity; public class MainActivity extends Activity {

 @Override

 public void onCreate(Bundle savedInstanceState) {

     super.onCreate(savedInstanceState);

 }

 

 public static void foo(){

     Log.d("TEST","Foo method is called is called");  

     

 }

}

i exported the project as a jar file and import it in my unity project in Standard Assets/Plugins/Android folder and when i press play , the console shows me these messages:

JNI: Unable to find field id for 'MainActivity' (static) JNI: Init'd AndroidJavaObject with null ptr! JNI: Unable to find method id for 'foo' (static)

i m testing this because i want to create a facebook android project in eclipse and export it as a jar file , import it in unity and show a facebook user id and build it in Android.

Thanks for your help