记录一个字符串出现的次数

package cn.lyun.zzj;

public class Test06 {
    public static void main(String[] args) {
    String str = "nba ernsdfbfa tnba ynba ui";
    String key = "nba";
    int count = getKeyStringCount( str, key);
    System.out.println("count = " +count);
}

    private static int getKeyStringCount(String str, String key) {
        int count = 0;
        if (!str.contains(key)) {
            return count;
        }
        int index = 0;
        while((index = str.indexOf(key))!=-1){
            str = str.substring(index+key.length());
            count ++;
        }
        return count;
    }
}