Merge Intervals

Given a collection of intervals, merge all overlapping intervals.

For example,
Given [1,3],[2,6],[8,10],[15,18],
return [1,6],[8,10],[15,18].

public class Solution {
    public ArrayList<Interval> merge(ArrayList<Interval> intervals) {
        if(intervals.size()==0)
            return intervals;
            
        Comparator<Interval> comparator = new Comparator<Interval>(){
            public int compare(Interval a,Interval b){
                return a.start-b.start;
                }   
        };
        
        Collections.sort(intervals,new sotr());
        ArrayList<Interval> result = new ArrayList<Interval> ();
        Interval temp = intervals.get(0);
        for(int i=1;i<intervals.size();i++){
            Interval cur = intervals.get(i);
            if(temp.end<cur.start){
                result.add(temp);
                temp = cur;
            }
            else if(temp.end>=cur.start){
                int left =Math.min(temp.start,cur.start);
                int right = Math.max(temp.end,cur.end);
                temp = new Interval(left,right);
            }
        }
        result.add(temp);
        return result;
    }
}