public static void main(String[] args) {
String str = "hjsdfhjdshsksdfsfdshierfshskssdfdsfsfhsk sdf";
String obj = "hsk";
int index = 0 , count = 0;
// System.out.println(str.startsWith(obj, 9));
//方法一:
/* while(str.indexOf(obj)!=-1){
index = str.indexOf(obj);
str = str.substring(obj.length()+index);
count++;
}*/
//方法二
/* while(str.indexOf(obj,index)!=-1){
index += str.indexOf(obj,index);
count++;
}*/
//方法三 当indexof的值为-1时,此表达式可以识别出来
while((index-1)!=(index+=str.indexOf(obj,index))){
count++;
}
System.out.println(str);
System.out.println(count);
}