Admob crashes my app Android (Eclipse) - eclipse

Question

I have been following a tutorial online on how to build android apps, everything went fine until today, I have been trying admob, first I followed the tutorial, my app crashed java and xml way of adding admob. Then I followed the instructions on admob.com same thing. Does anyone have an idea how to fix that? I am brand new to OOP (Java/Android).
Here is the error log:
03-01 20:02:06.910: E/AndroidRuntime(4670): <-- all lines started with that.
FATAL EXCEPTION: main
java.lang.NoClassDefFoundError: com.google.ads.AdView
at com.example.myfirstapp.Data.onCreate(Data.java:31)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1722)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1784)
at android.app.ActivityThread.access$1500(ActivityThread.java:123)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:939)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:130)
at android.app.ActivityThread.main(ActivityThread.java:3835)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
at dalvik.system.NativeStart.main(Native Method)
Data.java:
package com.example.myfirstapp;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RelativeLayout;
import android.widget.TextView;
import com.google.ads.AdRequest;
import com.google.ads.AdSize;
import com.google.ads.AdView;
public class Data extends Activity implements OnClickListener {
private AdView ad;
Button start, startFor;
EditText sendET;
TextView gotAnswer;
RelativeLayout rl;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.get);
initialize();
ad = new AdView(this, AdSize.BANNER, "a151303d6f29c9c");
rl = (RelativeLayout) findViewById(R.id.relLayout);
rl.addView(ad);
ad.loadAd(new AdRequest());
}
#Override
protected void onDestroy() {
// TODO Auto-generated method stub
if (ad != null) {
ad.destroy();
}
super.onDestroy();
}
private void initialize() {
// TODO Auto-generated method stub
start = (Button) findViewById(R.id.bSA);
startFor = (Button) findViewById(R.id.bSAFR);
sendET = (EditText) findViewById(R.id.etSend);
gotAnswer = (TextView) findViewById(R.id.tvGot);
start.setOnClickListener(this);
startFor.setOnClickListener(this);
}
#Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
switch (arg0.getId()) {
case R.id.bSA:
String bread = sendET.getText().toString();
Bundle basket = new Bundle();
basket.putString("key", bread);
Intent a = new Intent(Data.this, OpenedClass.class);
a.putExtras(basket);
startActivity(a);
break;
case R.id.bSAFR:
Intent i = new Intent(Data.this, OpenedClass.class);
startActivityForResult(i, 0);
break;
}
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
Bundle basket = data.getExtras();
String s = basket.getString("answer");
gotAnswer.setText(s);
}
}
}

Answer 1

My guess is that your Android project hasn't been configured correctly as the AdView class seems to be present at compile time but not at run time which indicates that the project does have a reference to the Admob library but the packaged app (the apk) doesn't.
Now because your question doesn't include the information on what development environment you are using, there's no concrete instruction I could give you to remedy the problem.
Of course it would also help if you could post the Data.java code, at least the onCreate() method to see what you are doing at line 31.