LeetCode - Length of Last Word

Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string.
If the last word does not exist, return 0.
Note: A word is defined as a character sequence consists of non-space characters only.

For example,
Given s = "Hello World",
return 5.


public class Solution {
    public int lengthOfLastWord(String s) {
        if(s==null) {
            return 0;
        }
        int l = 0;
        boolean begin = false;
        for(int i=s.length()-1;i>=0;i--) {
            char c = s.charAt(i);
            if(c==' ') {
                if(begin) {
                    break;
                } else {
                    continue;
                }
            } else {
                l++;
                begin = true;
            }
        }
        return l;
    }
}