ArrayList sort based on object field

Question

Possible duplicate:
Sort ArrayList Address List

I am storing DataNode objects in an ArrayList . The DataNode class has an integer field called degree . I want to get DataNode objects from nodeList in ascending order degree . How can i do this.

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

Answer 1

Modify the DataNode class so that it implements the Comparable interface.

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

then just use

 Collections.sort(nodeList); 

Answer 2

Use your own 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 3

You can use the Bean Comparator to sort any property in your custom class.