Thread: Read A File and Store Values into a 2-Dimensional Integer Array?

Hello! On top of the other program I have is one that deals with taking values from a file, "input.txt" (click on the file name), storing those values into a 2D array, and printing them out like so:

6 5 4 1
2 3 4 5
8 10 12 23
43 84 11 4

I also need to calculate the sum of the diagonal from the top left of the array to the bottom right of the array. In this case, the sum would be 25 (6+3+12+4).

And in addition to that, I need to make a transpose of that output and again calculate the sum of the diagonal from the top left of the array to the bottom right of the array like this:

6 2 8 43
5 3 10 84
4 4 12 11
1 5 23 4
Sum = 25

This is my code so far:

import java.io.*;
import java.util.*;
 
class Doubles
{
  public static void main (String []args)
  {
    try
    {
      int i, j, n = 4;
      int[][] array = new int[n][n];
      String line;
 
      FileInputStream fstream  = new FileInputStream("input.txt");
      Scanner scan = new Scanner(fstream);
      DataInputStream In = new DataInputStream(fstream);
      BufferedReader reader = new BufferedReader(new InputStreamReader(In));
 
      //Stores data into an array
      while ((line = reader.readLine()) != null)
      {
        array[0][0] = line;
      }
      reader.close();
      System.out.println("Here is the matrix version: ");
 
      for (i=0; i<n; i++)
      {
        for (j = 0; j<n; j++)
        { 
          System.out.print(array[i][j]);
        }
      }
    }
    catch (Throwable e)
    {
      System.out.println("This is not valid!"); 
    }  
  }
}

Obviously the code isn't done yet, but as you can tell I have no idea how to store the values into the 2D array, let alone calculate the sum and print that out. Any advice? Thanks in advance!

 //Stores data into an array
      while ((line = reader.readLine()) != null)
      {
        StringTokenizer line2 = new StringTokenizer(line);
 
        while (line2.hasMoreTokens())
        {
          array[column][row] = Integer.parseInt(line2.nextToken());
          column++;
        }
        row++;
      }

for (i=0; i<column; i++)
      {
        for (j=0; j<row; j++)
        {
          sum += array[i][j];
        }
      }
      System.out.println("The sum is: " + sum);
    }

When I try this the exception kicks in and states that it's not valid. I know it has to do with the fact that I'm going further than the array's limits, but what can I do then? "column" will keep incrementing past the array's limits in the first while loop.

Also, it doesn't print out how I want it to print out. How I want it to print out can be found in my original post.