Tugas Uas Algo

oke saya akan menampilkan hasil nya screenshots project saya yaitu membuat tiket konser 

private void closeButtonActionPerformed(java.awt.event.ActionEvent evt) {                                           

        // TODO add your handling code here:

        {

            System.exit(0);

        }

    }                        

private void NewButtonActionPerformed(java.awt.event.ActionEvent evt) {                                         

        // TODO add your handling code here:

        tiketkonser.Penjualankonser p = new tiketkonser.Penjualankonser();

        entityManager.persist(p);

        list.add(p);

        int row = list.size() - 1;

        masterTable.setRowSelectionInterval(row, row);

        masterTable.scrollRectToVisible(masterTable.getCellRect(row, 0, true));

    }                                         

private void saveButtonActionPerformed(java.awt.event.ActionEvent evt) {                                          

        // TODO add your handling code here:

        try {

            entityManager.getTransaction().commit();

            entityManager.getTransaction().begin();

        } catch (RollbackException rex) {

            rex.printStackTrace();

            entityManager.getTransaction().begin();

            List<tiketkonser.Penjualankonser> merged = new ArrayList<tiketkonser.Penjualankonser>(list.size());

            for (tiketkonser.Penjualankonser p : list) {

                merged.add(entityManager.merge(p));

            }

            list.clear();

            list.addAll(merged);

        }

    }                                          

private void hitungButtonActionPerformed(java.awt.event.ActionEvent evt) {                                            

        // TODO add your handling code here:

        float jumlahtiket=Float.parseFloat(jumlahtiketField.getText());

        float hargatiket=Float.parseFloat(hargatiketField.getText());

        float hargatotal=jumlahtiket*hargatiket;

        hargatotalField.setText(""+hargatotal);

    }                                           

private void refreshButtonActionPerformed(java.awt.event.ActionEvent evt) {                                             

        // TODO add your handling code here:

        entityManager.getTransaction().rollback();

        entityManager.getTransaction().begin();

        java.util.Collection data = query.getResultList();

        for (Object entity : data) {

            entityManager.refresh(entity);

        }

        list.clear();

        list.addAll(data);

    }                                            

private void deleteButtonActionPerformed(java.awt.event.ActionEvent evt) {                                            

        // TODO add your handling code here:

        int[] selected = masterTable.getSelectedRows();

        List<tiketkonser.Penjualankonser> toRemove = new ArrayList<tiketkonser.Penjualankonser>(selected.length);

        for (int idx = 0; idx < selected.length; idx++) {

            tiketkonser.Penjualankonser t = list.get(masterTable.convertRowIndexToModel(selected[idx]));

            toRemove.add(t);

            entityManager.remove(t);

        }

        list.removeAll(toRemove);

    }