public HashMap<String, String> validate() { HashMap<String, String> errors = new HashMap<String, String>(); if ("".equals(this.carPlate) || this.carPlate == null) { errors.put("Car Plate", "should not be empty"); } if ("".equals(this.referenceCode) || this.referenceCode == null) { errors.put("Reference Code", "should not be empty"); } DateFormat df = new SimpleDateFormat("yyyy-MM-dd"); try { if (Utility.dateDifference(df.parse(this.startDatetime), df.parse(this.endDateTime)) < 0) { errors.put("Start and End Date", "should not be Conflicting"); } } catch (Exception e) { errors.put("Start and End Date", "should be valid date"); } if (this.customerid <= 0) { errors.put("Customer ID", "should not be Null/Empty"); } return errors; }