Help with Android Logging

[Sam]

Hello All,
I am trying to implement logging on my android project. I am trying the following:

public class MainActivity extends Activity {
    /** Called when the activity is first created. */
  private static Logger log;
  private FileAppender appender;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        log = LoggerFactory.getLogger();
        PropertyConfigurator.getConfigurator(this).configure();
        this.appender = new FileAppender();
        PatternFormatter patternFormatter=new PatternFormatter();
        patternFormatter.setPattern("%d{DATE}  %m");
        this.appender.setFileName( "/sdcard/pra/prv_a.txt");
        this.appender.setFormatter(patternFormatter);
        log.setLevel(Level.DEBUG);
        log.addAppender(this.appender);
        log.debug("Testing");
        setContentView(R.layout.main);
    }
}

But when i check on the /sdcard/pra folder i do not see the file being created. Am i missing out on something? Kindly help me with this.

<b>Thanking you,
Regards,
S.A.Norton Stanley</b>