CODEWITHSUNDEEP
javaarraystext-files
user5358375
user5358375

Reputation: 21

Reading numbers from an array but all it's displaying is 0's

What i'm trying to do is put a text file in a matrix array then display all the numbers. I've got it to display the numbers but they are all zeros.

Here is my code:

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

public class is12177903 
{
public static int[][] read_input(String filename) throws FileNotFoundException
{
    int matrix [][] = null;

    BufferedReader buffer = new BufferedReader(new FileReader(filename));
    String line;
    int row = 0;
    int size = 0;
    try {
        while ((line = buffer.readLine()) != null) 
        {
            String[] vals = line.trim().split("\\s+");


            if (matrix == null) 
            {
                size = vals.length;

                matrix = new int[size][size];
            }

            for (int col = 0; col < size; col++) 
            {
                matrix[row][col] = Integer.parseInt(vals[col]); //this is line 31
            }

            row++;
        }
    } catch (NumberFormatException e) 
    {
        e.printStackTrace();
    } catch (IOException e) 
    {
        e.printStackTrace();
    }

    return matrix;

}

public static void printMatrix(int[][] matrix)
{
    String str = "";
    int size = matrix.length;


    if (matrix != null) {
        for (int row = 0; row < size; row++)
        {
            str += " ";
            for (int col = 0; col < size; col++)
            {
                str += String.format("%2d",  matrix[row][col]);
                if (col < size - 1) 
                {
                    str += "";
                }
            }
            if (row < size - 1) 
            {
                str += "\n";


            } 
        }
    }

   System.out.println(str); 
}

public static void main(String[] args) 
{
    int[][] matrix = null;

    try {
        matrix = read_input("AI2015.txt"); // this is line 83
    } catch (Exception e) {
        e.printStackTrace();
    }

    printMatrix(matrix);

}
}

The text file i'm reading from is just 26x26 with integers that are either 1 or 0.

I have some errors that show up every time i run it and I'm not sure what they mean: java.lang.NumberFormatException: For input string: "0"

at java.lang.NumberFormatException.forInputString(Unknown Source)

at java.lang.Integer.parseInt(Unknown Source)

at java.lang.Integer.parseInt(Unknown Source)

at is12177903.read_input(is12177903.java:31)

at is12177903.main(is12177903.java:83)

Upvotes: 2

Views: 88

Answers (2)

budi
budi

Reputation: 6541

As @Seelenvirtuose has stated, it is an issue with UTF-8 encoding.

However, I believe you do not need to edit your text file, just change your BufferedReader as so:

BufferedReader buffer = new BufferedReader(new InputStreamReader(
    new FileInputStream(filename), StandardCharsets.UTF_8));

Upvotes: 1

Seelenvirtuose
Seelenvirtuose

Reputation: 20618

Your file is saved in UTF-8 encoding with a byte order mark (BOM)!

The UTF-8 byte order mark consists of exactly three bytes: 0xEF 0xBB 0xBF. You are instantiating a FileReader, which will use the platform default encoding. In many cases this is ISO-8859-1. The characters you see, are the ISO-8859-1 characters for those three bytes. Obviously they are invalid input.

There are two solutions:

  1. Remove the BOM. UTF-8 BOMs are really uncummon, and there are many programs that cannot deal with it. So the best is, to not have it.

  2. Set the encoding to UTF-8 using an InputStream as in @budi's answer.

Upvotes: 2

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