Java - Reading from csv file getting null value

Question

I am getting a null value when im reading from my teachers. csv file. Column 1 which is att[0] works but att[1] returns 3 null values.

My csv looks like this: 1, Mr Murphy 2, Mr Davis 3, Ms Simpson Each on separate lines ie line 1 -> 1, Mr Murphy etc

Here is my code:

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class ReadCSV
{
    public static void main(String[] args)
    {
        //Input file which needs to be parsed
        String readTeachers = "teacher.csv";
        BufferedReader fileReader = null;

        //Delimiter used in CSV file
        final String DELIMITER = ",";

        try
        {
            String line = "";
            //String line = inFile.readLine();
            //Create the file reader
            fileReader = new BufferedReader(new FileReader(readTeachers));
            int count=0;
            String[] att = new String[10];
            //Read the file line by line
            while ((line = fileReader.readLine()) != null) 
            {
                //Get all tokens available in line
                String[] tokens = line.split(DELIMITER);

                int i=0;

                count++;
                for(String token : tokens)
                {
                    att[i] = token;
                    i++;
                    //Print all tokens
                   // System.out.println(token);

                    System.out.println(att[1]);
                    break;
                }


            }
            //System.out.println(count);
            //System.out.println(att[1]);
        } 
        catch (Exception e) {
            e.printStackTrace();
        } 
        finally
        {
            try {
                fileReader.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

You're printing out att[1] even on the first iteration, when you've only assigned a value to att[0]... so yes, at that point it will be null. Perhaps you wanted to print out att[i]? Have you executed this step by step in the debugger, and looked at tokens for each line? — Jon Skeet
– Jon Skeet, Commented Feb 13, 2016 at 16:22
I printed att[1] out of the for loop and still gives me a null value, but i am able to print att[0] out of the for loop — JWalters
– JWalters, Commented Feb 13, 2016 at 16:26

Dave · Accepted Answer · 2016-02-13 16:46:52Z

1

Your issue here is that you have a break statement inside the for loop that exits the loop at the end of the first iteration. Therefore, you are only putting a value in the first index of your array. Take out that statement and it should be fine.

            for(String token : tokens)
            {
                att[i] = token;
                i++;
                //Print all tokens
               // System.out.println(token);

                System.out.println(att[1]);
                break; // <---- ***take this out***
            }

answered Feb 13, 2016 at 16:46

Dave

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