文本中寻找某一单词出现次数

public class Temp {

    public static void main(String[] args) {
        String s = "frgjavajjavajjavahhjavajavajjjjavahjavahjavajava";
        
//        StringBuffer sb = new StringBuffer();
//        String[] str = s.split("java");
//        for (int i = 0; i < str.length; i++) {
//            if (str[i] != " ") {
//                sb.append(str[i]);
//            }
//        }
//        System.out.println((s.length() - sb.length()) / 4);
        
        int n = 0;
        int i=0;
        while (s.length() > 5) {
            i = s.indexOf("java");
            n++;
            s = s.substring(i + 4);
        }
        if (s.contains("java")) {
            n++;
        }
        System.out.println(n);
    }

}