StringTokeniser not reading data

Question

I've to read data from a file and I've just entered some sample data as a String in StringTokenizer. I can't understand what is wrong with my code here. Can someone please advise?

import java.util.StringTokenizer;

public class rough {

    public static void main(String[] args) throws Exception {
        StringTokenizer itr = new StringTokenizer("PKE2324 02-12-2020 200"
      + "\nMJD432 19-05-2019 150");

        while (itr.hasMoreTokens()){
            String line = itr.nextToken().toString();
            String[] tokens = line.split(" ");
            String[] date = tokens[1].split("-");
            String yr = date[2];
            String reg = tokens[0];
            String regy = new String(reg + " " + yr);
            System.out.println(regy);   
            }
     }

}

I want to get the registration number and year as a String. When I run this, I keep getting ArrayIndexOutofBounds

Did you debug and see why it is `ArrayIndexOutofBounds`? where exactly are you getting it? Can you share the stack trace? — Arun Gowda, Oct 17 '20 at 08:23

Deepak Tatyaji Ahire · Accepted Answer · 2020-10-17T08:38:58.710

This is the type of runtime error which has been caused due to logical error and inappropriate delimeter.

Assuming you want to tokenise the big string using newline character, use, \n as delimeter to StringTokenizer.

Have a look at the corrected code below which satisfies your use case:

import java.util.StringTokenizer;

public class rough {

    public static void main(String[] args) throws Exception {
        StringTokenizer itr = new StringTokenizer("PKE2324 02-12-2020 200"
    + "\nMJD432 19-05-2019 150", "\n");

        while (itr.hasMoreTokens()){
            String line = itr.nextToken().toString();
            String[] tokens = line.split(" ");
            String[] date = tokens[1].split("-");
            String yr = date[2];
            String reg = tokens[0];
            String regy = new String(reg + " " + yr);
            System.out.println(regy);   
            }
    }
}

Output:

PKE2324 2020
MJD432 2019

I was actually looking for something else and your answer did give an idea of how to get it. Thanks. I could get it to work without the delim. New to using stringtokenizer. — wakanada, Oct 17 '20 at 08:50

score -1 · Answer 2 · answered Oct 17 '20 at 08:31

Exception caused by this line

String[] tokens = line.split(" ");
String[] date = tokens[1].split("-");

line = PKE2324, so tokens[] = { "PKE2324" } --> length = 1 tokens[1] --> ArrayIndexOutOfBoundException

To fix this:

StringTokenizer itr = new StringTokenizer("PKE2324 02-12-2020 200"
      + "\nMJD432 19-05-2019 150");

Default delimeter is whitespace. You should pass delimeter in constructor if you want different delimeter.

StringTokeniser not reading data

2 Answers2