Java SE|获取一个字符串在另一个字符串中出现的次数

public class StringTest3 {
    public static int num(String fullStr,String partStr){
        int index = 0;
        int pIndex = 0;
        int cnt = 0;
        int partStrLength = partStr.length();

        for(;;){

            pIndex = fullStr.indexOf(partStr,index);
            if(pIndex != -1){//说明存在
                cnt++;
                index = pIndex + partStrLength;
            }else break;

        }
        return cnt;

    }
    public static void main(String[] args) {
        System.out.println(StringTest3.num("abkkcadkabkebfkabkskab","ab"));
    }
}