Optimization of measurement of disk-usage on Bitapplication filedir

In the BitarchiveAdmin constructor we traverse each Bitapplication basedir to find out how many bytes we have spent using the following the two lines of code;
final Long bytesUsedInDir = new Long(calculateBytesUsed(basedir));
log.info("Using bit archive directory '" + basedir + "' with "
+ bytesUsedInDir + " bytes of content and "
+ FileUtils.getBytesFree(basedir) + " bytes free");
After moving to Java 6 I suggest that we either don't bytesUsedInDir or
calculate bytesUsedInDir as "basedir.getTotalSpace() - FileUtils.getBytesFree(basedir)"