Sort an ArrayList based on an object field [duplicate]

Question

Possible Duplicate:
Sorting an ArrayList of Contacts

I am storing DataNode objects in an ArrayList. The DataNode class has an integer field called degree. I want to retrieve DataNode objects from nodeList in the increasing order of degree. How can I do it.

List<DataNode> nodeList = new ArrayList<DataNode>(); 

Answer 1

Use a custom comparator:

Collections.sort(nodeList, new Comparator<DataNode>(){      public int compare(DataNode o1, DataNode o2){          if(o1.degree == o2.degree)              return 0;          return o1.degree < o2.degree ? -1 : 1;      } }); 

Answer 2

Modify the DataNode class so that it implements Comparable interface.

public int compareTo(DataNode o) {      return(degree - o.degree); } 

then just use

Collections.sort(nodeList);