public void SaveTransaction(ArrayList<Tuple4<String, String, Integer, Date>> purchases) throws DataAccessException {
try {
String datFile = FileUtil.combinePath(this.dataDir, fileName);
ReverseFileReader r = new ReverseFileReader(datFile);
String lastLine = r.readNonEmptyLine();
Integer transactionId = 0;
if ( lastLine != null & !lastLine.equals(""))
{
String[] chunks = lastLine.split(",");