how to display google map on android emulator?

i am new to android development.please tell me how to generate key for google map keys from key store.I tried but i am getting the following error on the emulator.sorry the application hello google maps has stopped unexpectly

my codes are:: (HelloGoogleMaps.java)

package com.java4u.android;
import android.os.Bundle;
public class HelloGoogleMaps extends MapActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);      
    }
}

Hello Google map manifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.java4u.android"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="8" />

    <application android:icon="@drawable/icon" android:label="@string/app_name">

<activity android:name=".HelloGoogleMaps" android:label="@string/app_name"
     android:theme="@android:style/Theme.NoTitleBar">
     <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
       <uses-library android:name="com.google.android.maps" />
      <uses-permission android:name="android.permission.INTERNET" />

      </activity>
    </application>
</manifest>

Main.xml

 <?xml version="1.0" encoding="utf-8"?>
    <com.google.android.maps.MapView
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/mapview"
        android:layout_width="fill_parent"
        开发者_如何学编程android:layout_height="fill_parent"
        android:clickable="true"
        android:apiKey="Your Maps API Key goes here"
    />

Map Activity.java

package com.java4u.android;
import android.app.Activity;
public class MapActivity extends Activity {
    protected boolean isRouteDisplayed() {      
        return false;
    }   
}

MapView.java

package com.java4u.android;
public class MapView {
    public void setBuiltInZoomControls(boolean b) {
        MapView mapView = (MapView) findViewById(R.id.mapview);
        mapView.setBuiltInZoomControls(true);    
    }
    private MapView findViewById(int mapview) {
        // TODO Auto-generated method stub
        return null;
    }

}

As you already said, you need a Google Maps API key to use the MapView. Check this page for further information on how to get a key.

After getting the key, pass it to the android:apiKey attribute of the MapView in main.xml.

android:apiKey="Your Maps API Key goes here"

hi you have to add Api key in a main.xml

try this link get google Api key and display google map

http://mobiforge.com/developing/story/using-google-maps-android