Using Comparator to sort

This article will teach you how to use comparator to order your collections, if you don't know this before , It will greatly helps you.

For example , we have an object called paymentVO with lots of fields inside, our requirement is to do ascending or descending order following a field called "paymentSequenceNo"  to show it .

public static void ascendingSort(List<PaymentVO> list) {
 if (!list.isEmpty()) {
     Collections.sort(list,new Comparator() {

     @Override
     public int compare(Object o1, Object o2) {
          PaymentVO nVo1 = (PaymentVO) o1;
          PaymentVO nVo2 = (PaymentVO) o2;
          return nVo1.getBankTradePaymentSeqNo().compareTo(nVo2.getBankTradePaymentSeqNo());

  }});
 }
}

Similarly ,In descending order , Just change Collections.sort(..) to Collections.reverse(...) will do :

public static void desscendingSort(List<PaymentVO> list) {
   if (!list.isEmpty()) {

        Collections.reverse(list,new Comparator() {
        @Override
        public int compare(Object o1, Object o2) {
           PaymentVO nVo1 = (PaymentVO) o1;
           PaymentVO nVo2 = (PaymentVO) o2;
           return nVo1.getBankTradePaymentSeqNo().compareTo(nVo2.getBankTradePaymentSeqNo());

  }});
 }
}