Getting users location via network

gistfile1.java

Button btnLocation = (Button)findViewById(R.id.btnLocation);
btnLocation.setOnClickListener(new OnClickListener() {
	public void onClick(View arg0) {
		// Acquire a reference to the system Location Manager
		LocationManager locationManager = 
                     (LocationManager) AddressPOCActivity.this.getSystemService(Context.LOCATION_SERVICE);
		// Define a listener that responds to location updates
		LocationListener locationListener = new LocationListener() {
			public void onLocationChanged(Location location) {
				// Called when a new location is found by the network location provider.
				lat = Double.toString(location.getLatitude());
				lon = Double.toString(location.getLongitude());
				TextView tv = (TextView) findViewById(R.id.txtLoc);
				tv.setText("Your Location is:" + lat + "--" + lon);
			}

			public void onStatusChanged(String provider, int status, Bundle extras) {}
			public void onProviderEnabled(String provider) {}
			public void onProviderDisabled(String provider) {}
		};
		// Register the listener with the Location Manager to receive location updates
		locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
	}
});

Android Studio is not detecting 'addressPOCActivity', can you help me with it?