Analyze whether there is duplicate data in the list and repeat it several times

There is one List Stored in bean object  ,

List<CarPeccancy.ROWSDETAILBean> list = peccancy.getROWS_DETAIL();

Each of them bean The data is different , According to bean Of name Attribute to determine whether there is duplicate data .

Then we create a new one List Collective storage name The value of the property

List<String> carList = new ArrayList<>();
for (int i = 0; i < list.size(); i++) {
     carList.add(list.get(i).getCarnumber());
     }

Count each one name Number of occurrences

int number = 0;
int not = 0;
for (String temp : carList) {
    int frequency = Collections.frequency(carList, temp);
    if (frequency > 1) {
        number++;
        } else {
        not++;
         }
       }
System.out.println(" Duplicate data ：" + number);
System.out.println(" No duplicate data ：" + not);