updating jTable

i'v a jtable that displays database items; i'v inserts and updates too
i googled a lot but anyhow i cant manage it - how to have the table automaticaly updated
i tried several ways,like from input button action:

actually i'm using a solution that works in part, because it does refresh the jtable but conflitcs with the sorter class i'm using (from sun java tutorial):

i'm using this model:

class TableModelNotas extends AbstractTableModel {

private static final long serialVersionUID = 3945978682045222953L;

private boolean DEBUG = false;

FornecedorNotas fornecedor =  FornecedorNotas.getFornecedor();

Object[][] dados = fornecedor.dadosParaTabela();

private static TableModelNotas model;

private String[] nomeDaColuna = {

"Disciplina",

"Data",

"Prevista",

"Obtida"

};

public static TableModelNotas getModel() {

if (model == null)

model = new TableModelNotas();

return model;

}

public String getColumnName(int coluna) {

return nomeDaColuna[coluna];

}

public int getRowCount() {
 
return dados.length;

}

public int getColumnCount() {

return nomeDaColuna.length;

}

public Object getValueAt(int fila, int coluna) {

return dados[fila][coluna];

}
 
// <a href="http://java.sun.com/docs/books/tutorial/uiswing/components/examples/TableRenderDemo.java" target="_blank" rel="nofollow">http://java.sun.com/docs/books/tutorial/uiswing/components/examples/TableRenderDemo.java</a>

// Don't need to implement this method unless your table's editable.

public boolean isCellEditable(int row, int col) {

if (col < 2) {

return false;

}

else {

return true;

}

// Don't need to implement this method unless your table's editable.

public void setValueAt(Object value, int row, int col) {

if (DEBUG) {

System.out.println("Setting value at " + row + "," + col

+ " to " + value

+ " (an instance of "

+ value.getClass() + ")");

}

dados[row][col] = value;

fireTableCellUpdated(row, col);

if (DEBUG) {

System.out.println("New value of data:");

printDebugData();

}

private void printDebugData() {

int numRows = getRowCount();

int numCols = getColumnCount();

for (int i = 0; i < numRows; i++) {

System.out.print("    row " + i + ":");

for (int j = 0; j < numCols; j++) {

System.out.print("  " + dados[i][j]);

}

System.out.println();

}

System.out.println("--------------------------");

}
}

how can i achieve this?
TiA
[ October 08, 2006: Message edited by: miguel lisboa ]

after re-reading sun java tutorial on jTable, i added this to my code:

which is called when user pushes add button
inddeed the table refreshes, but overwrites last row
if i close and reenter my app, values are correct, but in fact this does not work
if i try adding one to the row count i get an error out of bounds...
dont knoow how to fix this