CODEWITHSUNDEEP
javatextfield
Yuxie
Yuxie

Reputation: 137

Java - Validation of TextField

(SOLVED) Issue 1: I am trying to add a simple verification to my 2 TextFields by checking its values. However, with this code below, I think whats happening is that the try/catch is called as the program starts up (which I tested with the System.out.println() code), therefore always resulting in an error. How can I make it such that this is called only after button 'Finish' is pressed?
(UNSOLVED) Issue 2: Following on from my first issue, how can I make it such that if either my if or my try/catch returns an 'error', then pressing the 'Finish' button doesn't end the code?

Code: 

    Dialog<Pair<String, Integer>> dialog = new Dialog();
    dialog.setTitle("Add new values");
    dialog.setHeaderText("Please input name and number");
    ButtonType finishButton = new ButtonType("Finish", ButtonData.OK_DONE);
    dialog.getDialogPane().getButtonTypes().addAll(finishButton, ButtonType.CANCEL);
    GridPane grid = new GridPane();
    grid.setHgap(10);
    grid.setVgap(10);

    TextField name = new TextField();
    name.setPromptText("Name");
    TextField size = new TextField();
    number.setPromptText("Number");

    grid.add(new Label("Name:"), 0, 1);
    grid.add(eventName, 1, 1);
    grid.add(new Label("Number:"), 0, 3);
    grid.add(eventSize, 1, 3);
    dialog.getDialogPane().setContent(grid);

    //verification code below
    if (eventName.getText() == null || eventName.getText() == "") {
        grid.add(new Label("Name is required!"), 0, 0);
    }
    try {
        int size = Integer.parseInt(eventSize.getText());
    } catch (NumberFormatException e) {
        grid.add(new Label("Size is required!"), 0, 1);
        System.out.println("Test failed");
    }

This is the code I am trying to learn off from: Here

Upvotes: 0

Views: 112

Answers (2)

DCON
DCON

Reputation: 628

Firstly, you must compare Strings using the .equals() method. I believe, but am not 100% certain, that the check for null is unnecessary. So, change:

if (eventName.getText() == null || eventName.getText() == "")

to

if (eventName.getText().equals(""))

I am unfamiliar with the Dialog class. However, when I need to implement something like this I like to use JDialog, and put it in a while loop:

    JPanel p = new JPanel(new GridLayout(2,2));
    JTextField nameField = new JTextField(5);
    JTextField numberField = new JTextField(5);
    JLabel nameLabel = new JLabel("Name");
    JLabel numberLabel = new JLabel("Number");

    p.add(nameLabel);
    p.add(nameField);
    p.add(numberLabel);
    p.add(numberField);

    while(true){
        int result = JOptionPane.showConfirmDialog(null, p, "Please enter Name and Number.", JOptionPane.OK_CANCEL_OPTION);

        if(result == JOptionPane.OK_OPTION){
            if(nameField.getText().equals("")){
                JOptionPane.showConfirmDialog(null, "Invalid input!");
            }
            else break;
        }
    }

This code should guide you on how you might be able to check for different inputs, and validate them accordingly. See JOptionPane for more details on the different dialogs you can open.

Hope this helps you.

Upvotes: 1

NJ645
NJ645

Reputation: 13

Dont know if this will help but i made a button that sounds like what your trying to do

//taking input from pop up box
JTextField InputPosX = new JTextField(5);
JTextField InputNegX = new JTextField(5);
JTextField InputY = new JTextField(5);
JPanel ChangeAxisPanel = new JPanel();
ChangeAxisPanel.add(new JLabel("Max X:"));
ChangeAxisPanel.add(InputPosX);
ChangeAxisPanel.add(Box.createHorizontalStrut(15)); // a spacer
ChangeAxisPanel.add(new JLabel("Min X:"));
ChangeAxisPanel.add(InputNegX);
ChangeAxisPanel.add(Box.createHorizontalStrut(15)); // a spacer
ChangeAxisPanel.add(new JLabel("Y:"));
ChangeAxisPanel.add(InputY);


int result = JOptionPane.showConfirmDialog(null, ChangeAxisPanel, 
    "Please Enter X and Y Values", JOptionPane.OK_CANCEL_OPTION);
    //if ok is pressed
    if (result == JOptionPane.OK_OPTION) {

        if(!(InputPosX.getText().isEmpty())){

          defaultPosX=Integer.parseInt(InputPosX.getText());
        }
        if(!(InputNegX.getText().isEmpty())){

          defaultNegX=Integer.parseInt(InputNegX.getText());
        } 
        if(!(InputY.getText().isEmpty())){
          defaultY=Integer.parseInt(InputY.getText());
         }
}
}
});

most of this was gathered from Here its a good link for gui input windows. also if you are looking for a simpler method you may want to look into jbutton's you can use it to call this window

Jbutton

anyways hope this helped

Upvotes: 0

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