字符串中字符的第N次出现并获得值

Question

I am using the below code to find the nth occurrence of , (comma) in the string. And once I get this, I need to get the value between this occurrence(nth) and next occurrence (n+1th occurrence)

Please let me know if I am going wrong somewhere.

 int ine=nthOccurence(line,18);  
         String strErrorCode=line.substring(ine,line.indexOf(",", ine+1));
String errorCode=strErrorCode.substring(1, strErrorCode.length());

The function

public static int nthOccurence(String strLine,int index)
  {

      char c=',';
            int pos = strLine.indexOf(c, index);
            while (index-- > 0 && pos != -1)
            {
                pos = strLine.indexOf(c, pos+1);
               // System.out.println("position is " +  pos);
            }
                return pos;
        }

Thanks.

Answer 1

Here's an alternative approach, also more readable:

public static String getAt(String st, int pos) {
    String[] tokens = st.split(",");
    return tokens[pos-1];
}

public static void main(String[] args) {
    String st = "one,two,three,four";
    System.out.println(getAt(st, 1)); // prints "one"
    System.out.println(getAt(st, 2)); // prints "two"
    System.out.println(getAt(st, 3)); // prints "three"
}

Answer 2

Something like this?

public static int nthOccurence(String strLine,int index){
  String[] items = strLine.split(",");
  if (items.length>=index)
      return items[index];
  else
      return "";//whatever you want to do it there's not enough commas
}