Count Palindrome in String

string 有多少palindrome substring。exp: 'aba' 返回4 , 'abba' 返回6

public class CountPalindrome {
	
	public int countPalindrome(String str){
		if(str == null || str.length() == 0) return 0;
		int count = 0;
		for(int i=0; i<str.length(); i++){
			//odd palindrome;
			count += find(str, i, i);
			 
			// even palindrome
			count+= find(str, i, i+1);
		}
		return count;
	}
	
	public int find(String str, int start, int end){
		int count = 0;
		while(start>=0 && end<str.length()){
			if(str.charAt(start) == str.charAt(end)){
				count++;
				start--;
				end++;
			} else {
				break;
			}
		}
		return count;
	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		CountPalindrome p = new CountPalindrome();
		System.out.println(p.countPalindrome("aba"));
		System.out.println(p.countPalindrome("abba"));
	}
}