Arraylist comparison with string based conditions

Question

Arraylist contains class model. Class has a parameter 'status' whose values would be 'open' , 'close' , ' upcoming '.

How to sort the arraylist based on ' status ' parameter i.e. 'open' should appear first, 'close' & 'upcoming' will be following to it respectively ?

Any help appreciated..

ready to help, pls try, post some code for us to start as well. — Ankur Singhal, Nov 04 '15 at 12:33

score 1 · Answer 1 · edited May 23 '17 at 12:29

1

You just need to implement the Comparable interface to your model class

Then implement the compareTo method with your compare logic.

And call Collections.sort(yourModelList); to make it.

You can find an example of implementing the Comparable interface here.

Hope this helps.

edited May 23 '17 at 12:29

Community

answered Nov 04 '15 at 12:34

Nanoc

score -1 · Answer 2 · answered Nov 04 '15 at 12:45

Unless the elements in your list have a notion of natural ordering, do not change YourClass to implement Comparable<YourClass>.

Instead, implement a Comparator<YourClass>, which is an entirely separate class:

class YourClassComparator implements Comparator<YourClass> {
  @Override
  public int compare(YourClass a, YourClass b) {
    // ... 
  }
}

and then pass an instance of this to Collections.sort:

Collections.sort(yourModelList, new YourClassComparator());

2 Answers2