Matrix output issue java

Question

Heres my code that displays i get no errors at all and it works but i have a little output issue with my thing

    // Lab13TEXT03st.java
// This is the student starting version of the Lab13 assignment.
// Testing <main> methods are provided for the 80-point and 100-point versions.
// This means that this version will not compile as provided.


import java.util.ArrayList;


public class Lab13TEXT03st
{
    public static void main(String[] args) 
    {
        System.out.println("\nLAB26A 80-POINT VERSION\n"); 

        Matrix m2 = new Matrix(3, 5, 100); 
        //m2.displayMatrix("Matrix m2 3 X 5 Display"); 
        System.out.println(); 
        int count = 100; 

        System.out.println("Matrix m1 Default Display"); // 
        System.out.println("Matrix has no elements"); // 
        System.out.println("");

        int pos = 0;

        for (int r = 0; r < m2.getRows(); r++) 
        { 
        //System.out.println("r = " + r); // 

        for (int c = 0; c < m2.getCols(); c++) 
        { 
            m2.setValue(r,c,count, pos);
            pos++;
            count++; 
            //System.out.println("r = " + r + " c = " + c + " and count = " + count); // 
        } 
            //System.out.println(""); // 
        } 



        m2.displayMatrix("Matrix m2 3 x 5 Consecutive Integers Display"); 
        System.out.println(); 



        Matrix m3 = new Matrix(3,3,100);                
        m3.displayMatrix("Matrix m3 3 X 3 Initialized to 100 Display");
        System.out.println();
    }


}




    class Matrix {

    private ArrayList list; // one-dimensional array stores matrix values 
    private int listSize; // total number of elements in the matrix 
    private int numRows; // number of rows in the matrix 
    private int numCols; // number of cols in the matrix 

    public Matrix(int r, int c, int value){ 
        list = new ArrayList(); 
        numRows = r; 
        numCols = c; 
        listSize = r * c; 

    //for(int i = 0; i < listSize; i++) 
    // list.add(new Integer(value)); 
    } 

    public int getRows(){ 
        return numRows; 
    } 

    public int getCols(){ 
        return numCols; 
    } 

    public int getSize()
    { 
        return listSize; 
    } 

    public int getValue(int r, int c)
    { 
        int rowLength = getRows(); 
        int colLength = getCols();
        //System.out.println("r in get = " + r);
        int position = (r * colLength) + c;
        //int position = ((r + 1) * rowLength) - rowLength + c; // one to multi-dimensional array index conversion
        //System.out.print("Pos get = " + position + "; ");
        return ((Integer)list.get(position)).intValue(); 
    } 

    public void setValue(int r, int c, int value, int pos)
    { 
        int rowLength = getRows(); 
        //int colLength = getCols(); 
        //int position = ((r + 1) * rowLength) - rowLength + c; // one to multi-dimensional array index conversion 
        //System.out.println("Pos set = " + position + "; ");
        list.add(pos,new Integer(value)); 
    } 

    public void displayMatrix(String str)
    { 

    System.out.println(str); 

    for(int j = 0; j < getRows(); j++){ 
    for(int i = 0; i < getCols(); i++){ 
    System.out.print(getValue(j, i) + " "); 
    } 
        System.out.println(""); 
    } 
}
}

My output is wrong and i need some help please

I get no errors... here is my output

    LAB26A 80-POINT VERSION


Matrix m1 Default Display
Matrix has no elements

Matrix m2 3 x 5 Consecutive Integers Display
100 101 102 103 104 
105 106 107 108 109 
110 111 112 113 114 

Matrix m3 3 X 3 Initialized to 100 Display
Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
    at java.util.ArrayList.RangeCheck(ArrayList.java:547)
    at java.util.ArrayList.get(ArrayList.java:322)
    at Matrix.getValue(Lab13TEXT03st.java:128)
    at Matrix.displayMatrix(Lab13TEXT03st.java:147)
    at Lab13TEXT03st.main(Lab13TEXT03st.java:49)

Process completed.

It needs to output like this though:

    LAB13TEXT03 80-POINT VERSION

Matrix m1 Default Display
Matrix has no elements

Matrix m2 3 X 5 Display
0  0  0  0  0
0  0  0  0  0
0  0  0  0  0

Matrix m2 3 X 5 Consecutive Integers Display
100  101  102  103  104
105  106  107  108  109
110  111  112  113  114

Matrix m3 3 X 3 Initialized to 100 Display
100  100  100
100  100  100
100  100  100

Please help

Answer 1

The second matrix (m3) fails because you haven't initialized it yet, as you did with m2. You never wrote something along the lines m3.setValue(...) in the code. Alternatively, for initializing the matrix with a default value, you need to uncomment these lines in the constructor of Matrix:

for(int i = 0; i < listSize; i++)
    list.add(new Integer(value));