Question

I’m having trouble getting the input for a 2-d array for an assignment. Basically I have to create a bug that crawls across the screen and writes an ASCII image of our name. We have to get the input from the text file so i figured the best course of action would be to create a 2-d array for each character in a file and have it determine what it does depending on what character is in each spot. However It always shows that the 2-d array has the same contents (shown below)

[[C@b1c5fa

Below is an example of the class, the tester class, and an example of the txt file. How can i get it to show the correct input?

Bug Class

import java.io.*;
import java.util.*;

public class Bug
{  

   private int startingPoint;
   private char mrBug;
    private char placeholder;
    private int postition;
    private int matrixLength;
    private int matrixRows;
    private String lineGet;
    private String txtFile;
    private char[][] Data = new char[3][];


   /**
      Constructs a computer class with title, days, time and room
   */
   public Bug(int initialPosition, char bug, String inputFile)
   {   
     startingPoint = initialPosition;
     mrBug = bug; 
      txtFile = inputFile;
   }


          public void matrixPrinter()
   {   
    for(int row = 0; row < Data.length; row++)
        {
            for(int col = 0; col < Data[row].length; col++)
            {
            System.out.print(Data[row][col]);
            }
            System.out.print("\n");
        }

   }//End of matrixBuilder Method

    public void matrixBuilder()
   {   
        Scanner in = new Scanner(txtFile);
        matrixRows = 0;
        while (in.hasNextLine())
            {
                lineGet = in.next();
                matrixLength = lineGet.length();
                Data[matrixRows] = new char[matrixLength];
                for(int i = 0; i < matrixLength; i++)
                {
                    placeholder = lineGet.charAt(i);
                    Data[matrixRows][i]= placeholder;

                }//End of For
                matrixRows++;
            }//End of While
        in.close();
   }//End of matrixBuilder Method

    /**
      Gets the title
      @return the title
   */
    public void turn()
   {   
        //return title;

   }

   public void move()
   {   
      // your work here
   }

   /**
      Gets Postition
      @return the postition
   */
   public int getPostion()
   {   
    return postition;

   }
}

http://pastebin.com/g9LWFyXQ

Bug Tester

import java.util.*;
import java.io.*;

public class BugTester
{
   public static void main(String[] args)
   {
        int start = 0;
       char bugSymbol = 'a';
        String inputFile = "peter.txt";
      Bug crawler1 = new Bug(start,bugSymbol,inputFile);
          crawler1.matrixBuilder();
        crawler1.matrixPrinter();

   }
}

Txt file:

/#****#****#*****#****#****#****#\
/#*##*#*######*###*####*##*#*##*#\
/#****#****###*###****#****####*#\
/#*####*######*###*####*#*#####*#\
/#*####****###*###****#*##*####*#\

Answer 1

First: One mistake is in your matrixBuilder() method.

You init Scanner, passing name of your file to the constructor:

Scanner in = new Scanner(txtFile);

So it doesn’t read the file contents when you call:

in.next();

The lineGet variable has the “peter.txt” value. It’s obviously not what you want.

You need to init Scanner that way:

    Scanner in = null;
    try {
        in = new Scanner(new FileInputStream(txtFile));
    } catch (FileNotFoundException ex) {
        // work up exception
    }

Or just

public void matrixBuilder() throws FileNotFoundException {
    Scanner in = new Scanner(new FileInputStream(txtFile));
//...
}

Second:
The initial size of your Data array is incorrect:

private char[][] Data = new char[3][];

Your file “peter.txt” has at least 5 lines.
So, the initial size of your Data array should also be 5.

After correcting this mistakes you should get the desired result.

Hope this helps.

UPDATE:

Complete working code:

Bug.java

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class Bug {
    private int startingPoint;
    private char mrBug;
    private char placeholder;
    private int postition;
    private int matrixLength;
    private int matrixRows;
    private String lineGet;
    private String txtFile;
    private char[][] Data = new char[5][];

    /**
    Constructs a computer class with title, days, time and room
     */
    public Bug(int initialPosition, char bug, String inputFile) {
        startingPoint = initialPosition;
        mrBug = bug;
        txtFile = inputFile;
    }

    public void matrixPrinter() {
        System.out.println("Data:");

        for (int row = 0; row < Data.length; row++) {
            for (int col = 0; col < Data[row].length; col++) {
                System.out.print(Data[row][col]);
            }
            System.out.print("\n");
        }

    }//End of matrixBuilder Method

    public void matrixBuilder() throws FileNotFoundException {
        Scanner in = new Scanner(new FileInputStream(txtFile));

        matrixRows = 0;
        // We should also check that the number of lines in the file 
        // doesn't exceed the Data array size.
        while (in.hasNextLine() && matrixRows < Data.length) {
            lineGet = in.next();
            System.out.println("line["+ matrixRows + "]:" + lineGet);
            matrixLength = lineGet.length();
            Data[matrixRows] = new char[matrixLength];
            for (int i = 0; i < matrixLength; i++) {
                placeholder = lineGet.charAt(i);
                Data[matrixRows][i] = placeholder;

            }//End of For
            matrixRows++;
        }//End of While
        in.close();
    }//End of matrixBuilder Method

    /**
    Gets the title
    @return the title
     */
    public void turn() {
        //return title;
    }

    public void move() {
        // your work here
    }

    /**
    Gets Postition
    @return the postition
     */
    public int getPostion() {
        return postition;

    }
}

BugTester.java

import java.io.FileNotFoundException;

public class BugTester {

    public static void main(String[] args) throws FileNotFoundException {
        int start = 0;
        char bugSymbol = 'a';
        String inputFile = "peter.txt";
        Bug crawler1 = new Bug(start, bugSymbol, inputFile);
        crawler1.matrixBuilder();
        crawler1.matrixPrinter();
    }
}