Now the Problem how can i get the DefaultTableModel to accept ArrayLists instead of vectors?
You can't use the DefaultTableModel with ArrayLists.
You need to create a custom TableModel.
One approach would be to copy the code for the DefaultTableModel and the change the references to a Vector to be references to an ArrayList.
Another approach would be to create a more generic TableModel that can use any List. Both Vectors and ArrayLists implement the List interface, so create a model that implements the interface not the concrete implementation of the List. This is a little more complicated, but more flexible. For a working example of this approach you can check out my implementation of a
List Table Model.