Comparison method violates its general contract using string compareTo and after null equal check

I've seen a lot of post on this problem and almost every one of them is because the code was not transitive and the original poster did not handle the case where object 1 && object 2 == null, but I have handled it in this case and I am still getting this error.

private static Comparator<MyObject> sortByDateComparator() {      return (o1, o2) -> {           if (o1 == null && o2 == null) {               return 0;          }            if (o1 == null) {              return 1;          }            if (o2 == null) {              return -1;          }            if (TextUtils.isEmpty(o1.eventTime())) {              if (TextUtils.isEmpty(o2.eventTime())) {                  return 0;              }              else {                  return 1;              }          }          else if (TextUtils.isEmpty(o2.eventTime())) {              return -1;          }            return o2.eventTime()                  .compareTo(o1.eventTime());      };  }    public static ArrayList<MyObject> sortByDate(ArrayList<MyObject> obj) {      Collections.sort(obj, ThisClass.<MyObject>sortByDateComparator());      return obj;  }  

The eventTime attibute is a simple string public String eventTime = DateUtil.getCustomDateClassInstance().getZeroUtcTime(); //init with epoch time

I sometimes get this crash but it is pretty rare.

Comparison method violates its general contract!  

https://stackoverflow.com/questions/67393947/comparison-method-violates-its-general-contract-using-string-compareto-and-after May 05, 2021 at 09:04AM