Java判断1个字符串中出现了几次其他字符串

public class Test {
        public static int count(String text,String sub){
            int count =, start =;
            while((start=text.indexOf(sub,start))>=){
                start += sub.length();
                count ++;
            }
            return count;
        }
        public static void main(String[] args){
            String text ="nihaoksdoksad";
            String sub ="o k";
            System.out.println(count(text,sub));
        }
    }