Meeting Rooms leetcode

Given an array of meeting time intervals consisting of start and end times [[s1,e1],[s2,e2],...] (si < ei), determine if a person could attend all meetings.

For example,
Given [[0, 30],[5, 10],[15, 20]],
return false.

public class Solution {
    public boolean canAttendMeetings(Interval[] intervals) {
        if (intervals == null || intervals.length == 0) {
            return true;
        }
        Comparator com = new Comparator() {
            public int compare(Interval i1, Interval i2) {
                return i1.start - i2.start;
            }
        };
        Arrays.sort(intervals, com);
        Interval tem = intervals[0];
        for (int i = 1; i < intervals.length; i++) {
            Interval next = intervals[i];
            if (next.start < tem.end) {
                return false;
            }
            tem = next;
        }
        return true;
    }
}