LintCode Two Strings Are Anagrams

public class Solution {
    /**
     * @param s: The first string
     * @param b: The second string
     * @return true or false
     */
    public boolean anagram(String s, String t) {
        if(s == null || t == null) return false;
        if(s.length() != t.length()) return false;
        
        char[] arrs = s.toCharArray();
        char[] arrt = t.toCharArray();
        Arrays.sort(arrs);
        Arrays.sort(arrt);
        
        boolean flag = true;
        for(int i = 0; i < arrs.length; i++){
            if(arrs[i] != arrt[i]){
                flag = false;
                
            }
        }
        return flag;// write your code here
    }
};