How do I sort a list by different parameters at different timed

by

I think your enum approach is basically sound, but the switch statements really need a more object oriented approach. Consider:

enum PersonComparator implements Comparator<Person> {
    ID_SORT {
        public int compare(Person o1, Person o2) {
            return Integer.valueOf(o1.getId()).compareTo(o2.getId());
        }},
    NAME_SORT {
        public int compare(Person o1, Person o2) {
            return o1.getFullName().compareTo(o2.getFullName());
        }};

    public static Comparator<Person> decending(final Comparator<Person> other) {
        return new Comparator<Person>() {
            public int compare(Person o1, Person o2) {
                return -1 * other.compare(o1, o2);
            }
        };
    }

    public static Comparator<Person> getComparator(final PersonComparator... multipleOptions) {
        return new Comparator<Person>() {
            public int compare(Person o1, Person o2) {
                for (PersonComparator option : multipleOptions) {
                    int result = option.compare(o1, o2);
                    if (result != 0) {
                        return result;
                    }
                }
                return 0;
            }
        };
    }
}

An example of usage (with a static import).

public static void main(String[] args) {
    List<Person> list = null;
    Collections.sort(list, decending(getComparator(NAME_SORT, ID_SORT)));
}

More Related Contents:

  1. Write a function that will sort a string array using Java
  2. In selection sort, if we have two duplicate elements, what is the behavior of the algorithm?
  3. Sort ArrayList of custom Objects by property
  4. Why is there no SortedList in Java?
  5. How do I use Comparator to define a custom sort order?
  6. How to sort an array of objects in Java?
  7. How to sort Date which is in string format in java?
  8. Why does my sorting loop seem to append an element where it shouldn’t?
  9. Android-java- How to sort a list of objects by a certain value within the object
  10. Sorting Strings that contains number in Java [duplicate]
  11. Sorting 2D array of strings in Java
  12. Why does Collections.sort use Mergesort but Arrays.sort does not?
  13. Java List Sorting: Is there a way to keep a list permantly sorted automatically like TreeMap?
  14. Java Sorting based on Enum constants
  15. Sort a List of objects by multiple fields [duplicate]
  16. How to check if array is already sorted
  17. How can I sort a JSONArray in JAVA [duplicate]
  18. Android how to sort JSONArray of JSONObjects
  19. sorting integers in order lowest to highest java
  20. Why does my JTable sort an integer column incorrectly?
  21. JTable + Sorting specific field
  22. Using a prepared statement and variable bind Order By in Java with JDBC driver
  23. Sort List of Strings with Localization
  24. sorting a List of Map
  25. ‘MergeSort Algorithm’ – What’s the better implementation in JAVA? [closed]
  26. java: Arrays.sort() with lambda expression
  27. Sorting ArrayList of Objects by Object attribute
  28. Why Collections.sort uses merge sort instead of quicksort?
  29. database sort vs. programmatic java sort
  30. Create a SortedMap in Java with a custom Comparator

Leave a Comment