JTable: how to avoid duplicate rows and aggregate item quantities

Question

I'm a newbie software developer, interested in Java desktop and web applications. I'm writing a desktop application, using only Swing components, which reads codes and, by retrieving the relative fields from a database, writes them in a JTable. I'm having troubles because the program adds a new row with the same code as many times as I enter the code, instead of increasing the quantity column of the already-entered code.

I want the program to perfom a check on the first column, by iterating the search on every row until it finds the code, if present, or reaches the last row. If it's a new code, a row must be added, instead if it's an already-entered code, the actual item quantity must be increased by one. Below comes my solution, not working, may you help? Thank you for the attention.

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

     try {

         item = Item.findItem(itemTextField.getText(), DeskApp.conn);

         // Definition and initialisation of control variables pertaining "while" cycle
         boolean isCodePresent = false;
         int row = 0;
         double discount = 0.0d;
         double colSum = 0.0d;

         // Discounted price = unit price * qty * (1 - discount)

         while (!isCodePresent && row < defMod.getRowCount()) {

             // Code already present: add quantity

             if (item.getCode() == defMod.getValueAt(row, 0)) {
                 int actualQty = (int)defMod.getValueAt(row, 4);
                 defMod.setValueAt(++actualQty, row, 4);
                 double unitPrice = (double) defMod.getValueAt(row, 3);
                 discount = (double)defMod.getValueAt(row, 5);
                 double totRow = unitPrice * actualQty * (100 - discount) / 100;
                 defMod.setValueAt(totRow, row, 6);
                 double discountedPrice = (double)defMod.getValueAt(row, 3) *
                      (double)defMod.getValueAt(row, 4) *
                              ((100 - (double)defMod.getValueAt(row, 5) / 100));
                 defMod.setValueAt(discountedPrice, row, 6);
                 isCodePresent = true;
             }

             row++;
         }

         // Code not yet present: add row

         if (!isCodePresent) {
             MyButton buttonAdd = new MyButton(MyButton.BEHAVIOUR_ADD, table.getRowCount());
             MyButton buttonRemove = new MyButton(MyButton.BEHAVIOUR_REMOVE, table.getRowCount());
             MyButton buttonDeleteRow = new MyButton(MyButton.BEHAVIOUR_DELETE_ROW, table.getRowCount());

             buttonAdd.setText("+1");
             buttonRemove.setText("-1");
             buttonDeleteRow.setText("Delete row");

             DecimalFormat digitFormat = new DecimalFormat("#.##");

             for (int i = 0; i < defMod.getRowCount(); i++) {
                 colSum += (double) defMod.getValueAt(i, 6);
             }

             double discountedPrice = (double)defMod.getValueAt(row, 3) * 
                  (double)defMod.getValueAt(row, 4) *
                       ((100 - (double)defMod.getValueAt(row, 5) / 100));
             defMod.addRow(new Object[]{item.getCode(), item.getOtherCode(),
                     item.getDescription(), item.getPrice(), 1, discount,
                           item.getPrice(), buttonAdd, buttonRemove, buttonDeleteRow});
         }

score 3 · Answer 1 · edited May 23 '17 at 12:13

3

You appear to be adding components directly to the TableModel. Instead use an appropriate renderer and editor.

Alternatively, to accomodate unpredictable database latency, query the database in the background of a SwingWorker, publish() interim results, and update the TableModel in your implementation of process(). A related example that reads form a flat-file is seen here.

edited May 23 '17 at 12:13

Community

1
1

answered Oct 31 '14 at 17:06

trashgod

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@pees Thank you for your quick answer and, nevertheless, for the attention. I'm out this weekend and couldn't implement your solution, but will do this Monday. Thanks also to Peeskillet for editing my first post ever here at Stackoverflow – Allicca Momo Nov 01 '14 at 13:24

JTable: how to avoid duplicate rows and aggregate item quantities

1 Answers1