+ return "Wrong date range. The date1 is later than date2.";
+
+ return null;
+ }
+
+ /**
+ * gives the current date in the form of string (yyyy/mm/dd)
+ *
+ * @return the current date
+ */
+ protected String getCurrentDate() {
+ Calendar cal = Calendar.getInstance();
+ String date = cal.get(Calendar.YEAR) + "/" + (cal.get(Calendar.MONTH) + 1) + "/" + cal.get(Calendar.DAY_OF_MONTH);
+ return date;
+ }
+
+ /**
+ * gives the earliest date in the system (through a direct call of a
+ * Cassandra related class) in the form of string (yyyy/mm/dd)
+ *
+ * @return the current date
+ */
+ protected String getEarliestDate() {
+ return DateFormatter.DateLongToString(CassandraReader.earliestDate(), formaterYYMMDD);