Modify layout to replace com.google.android.gms.maps.MapFragment with com.google.android.gms.maps.SupportMapFragment.
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:text="@string/hello_world" />
    <fragment
        android:id="@+id/map"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        class="com.google.android.gms.maps.SupportMapFragment"/>
</RelativeLayout>
Modify main code to extend android.support.v4.app.FragmentActivity, rather than Activity. Otherwise, AndroidRuntime will be Caused by: java.lang.ClassNotFoundException: android.view.fragment in loader dalvik.system.PathClassLoader.
package com.example.androidmapsv2;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
public class MainActivity extends FragmentActivity {
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
 }
}
The series:
A simple example using Google Maps Android API v2, step by step.

