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Thread: how to check is DOUBLE JTEXTFIELD is empty?

  1. #1
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    Default how to check is DOUBLE JTEXTFIELD is empty?

    hi I've been working this for 2 days and even google it but I can't figured the right answer.
    I can check STRING if it is empty.
    here is my code


     
     private void saveButton3ActionPerformed(java.awt.event.ActionEvent evt) {                                            
            String inventcodef = inventCodeField.getText();
            String inventnamef = inventNameField.getText();
            String categ = cmbname.getSelectedItem().toString();
            double inventreorderf = Double.parseDouble(inventReorderField.getText());
            String inventlocf = inventLocationField.getText();
            String inventstat = inventStatusArea.getText();
     
     
     
     
                if ((inventcodef.trim().length()==0) || (inventnamef.trim().length()== 0)||(inventreorderf == 0))
            {
     
             JOptionPane.showMessageDialog(null,"Item Code / Item Name / ReOrderpoint is empty!");  
     
     
            }
                else
     
            try {
                String SQL2 = "INSERT INTO inventory VALUES ("
                        + "'" + inventcodef + "'" + ","
                        + "'" + inventnamef + "'" + ","
                          + "'" + categ + "'" + ","
                        + "'" + inventreorderf + "'" + ","
                        + "'" + inventlocf + "'" + ","
                        + "'" + inventstat + "'"
                        + ")";
     
                PreparedStatement stamt = connect.prepareStatement(SQL2);
                stamt.executeUpdate();
                Double.parseDouble(inventReorderField.getText());
     
                JOptionPane.showMessageDialog(null,"Item Code: " + inventcodef + " Successfully saved!");
     
            }
              catch (NumberFormatException e)
              {
     
             JOptionPane.showMessageDialog(null,e.getMessage());
             inventReorderField.selectAll();
             inventReorderField.requestFocus();
             return;
     
              }
     
            catch (Exception f)
                {
                 JOptionPane.showMessageDialog(null,(f.getMessage())); 
            }
     
     
     
        }

    Thank you!


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    Default Re: how to check is DOUBLE JTEXTFIELD is empty?

    == null;

    ? does that not work?

    I looked using Google and I found this as well,
    jtextfield.getText().trim().length() >=0

    unfortunately I don't know much about GUI form methods, so i don't even know if DOUBLE jtextfield is a special type of jtextfield.
    anyway, maybe the generic ideas help anyway.

    Good-luck,
    Jonathan
    Last edited by JonLane; February 22nd, 2012 at 12:15 AM.

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    Default Re: how to check is DOUBLE JTEXTFIELD is empty?

    a) You should learn how to use a PreparedStatement correctly (eg using parameters) b) You can use Double.parseDouble and catch any exceptions that may be thrown - alternatively use a regular expressions to check the entered value matches the appropriate pattern

    == null;

    ? does that not work?

    I looked using Google and I found this as well,
    jtextfield.getText().trim().length() >=0

    unfortunately I don't know much about GUI form methods, so i don't even know if DOUBLE jtextfield is a special type of jtextfield.
    I would recommend you become familiar with the API and methods being used prior to trying to make recommendations to others

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