运行HelloGoogleMaps时出错

Question

我尝试了mapView教程，但它没有用，我按照教程的第一部分

代码有什么问题？

package tovar.hellogooglemaps;

import android.os.Bundle;
import android.view.Menu;

import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;

public class HelloGoogleMaps extends MapActivity {


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    MapView mapView = (MapView) findViewById(R.id.mapview);
    mapView.setBuiltInZoomControls(true);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;    
}
@Override
protected boolean isRouteDisplayed() {
    // TODO Auto-generated method stub
    return false;
}

}

当它在模拟器上运行时，应用程序崩溃