How can I limit JTextField to numbers, or prvent the damage of letters?

Question

I am using a two dimensional array of JTextFields to take in x y points, and graph them on a JPanel.

What is the best way to either limit the input to numbers, or prevent letter from blowing up my program?

Here is a snippet of code, that does not like when an letter is entered.

Float smallX = Float.parseFloat(xyInput[0][0].getText());
            for (Integer i = 0; i < xyInput.length; i++) {
                String number = xyInput[i][0].getText();
                Float testX = Float.parseFloat(number);

                if (smallX > testX) {
                    smallX = testX;
                    System.out.println("smallX = " + smallX);
                }
            }

Thanks for all your help!

[For example](http://stackoverflow.com/a/11093360/522444) – Hovercraft Full Of Eels Dec 15 '14 at 23:55 — Hovercraft Full Of Eels, Dec 15 '14 at 23:55

score 1 · Answer 1 · answered Dec 15 '14 at 23:55

JFormattedTextField - post validation; see How to Use Formatted Text Fields
JSpinner - post validation; see How to Use Spinners
InputVerifer - post validation; see Validating Input
DocumentFilter - real time validation; see Implementing a Document Filter and DocumentFilter Examples

How can I limit JTextField to numbers, or prvent the damage of letters?

1 Answers1