private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
        // TODO add your handling code here:

        DefaultTableModel model = new DefaultTableModel(new String[]{"Heading 1", "Heading 2", "Heading 3"}, 0);
        try {



            Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mysql", "root", "");

            Statement stmt = conn.createStatement();

            String sql = "SELECT * FROM tablename";
            ResultSet rs = stmt.executeQuery(sql);
            while (rs.next()) {
                String v1 = rs.getString("className");
                String v2 = rs.getString("homeWork");
                String v3 = rs.getString("dueDate");

                  model.addRow(new Object[]{v1,v2, v3});
            }
            jTable1.setModel(model);
        } catch (SQLException ex) {

        }

    }