Listar dados do meu Banco de dados na JTable

public List<Contato> listar() throws SQLException{
            Connection conn = Conexao.getConexao();
            String sql = "Select * from usuario";
            PreparedStatement stmt = conn.prepareStatement(sql);
            ResultSet rs = stmt.executeQuery();
            List<Contato> minhaLista = new ArrayList<Contato>();
            while(rs.next()){
	   Contato contato = new Contato(rs.getString("nome"),rs.getString("idade"),rs.getString("telefone"));
                   minhaLista.add(contato);
                }
             rs.close();
            stmt.close();
           return minhaLista;

jTable1 = new javax.swing.JTable();
  jTable1.setModel(new javax.swing.table.DefaultTableModel(
    new Object [][] {
        {null, null, null, null},
        {null, null, null, null},
        {null, null, null, null},
        {null, null, null, null}
    },
    new String [] {
        "Idusuario", "Nome", "Idade", "Telefone"
    }
) {
    Class[] types = new Class [] {
        java.lang.Integer.class, java.lang.String.class, java.lang.String.class, java.lang.String.class
    };

    public Class getColumnClass(int columnIndex) {
        return types [columnIndex];
    }
});
jScrollPane1.setViewportView(jTable1);