Matrix with ArrayList
<p>I got this class :</p>

<pre><code>import java.util.*;

public class MatrixArrayList extends AbstractMatrix {
    private ArrayList&lt;ArrayList&lt;Integer&gt;&gt; values;

    public MatrixArrayList(int nbl, int nbc) {
        super(nbl, nbc);
        values=new ArrayList&lt;ArrayList&lt;Integer&gt;&gt;();
    }


    @Override
    public int getValue(int x, int y) {
        return values.get(x).get(y) ;
    }

    @Override
    public void setValue(int x, int y, int value) {
        values.get(x).set(y, value);

    }   
}
</code></pre>

<p>and I got</p>

<pre><code>java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
</code></pre>

<p>I want to make a matrix with an <code>ArrayList</code>
i have w problem with this : 
valeurs.get(x).set(y, valeur);</p>