How to prevent a user inputing numeric values

Question

I'm creating a GUI for a club and am trying to set up a test so that when a new user is prompted to input their name, they will not be able to input any numeric values.

Here is the code I have so far:

else if((this.jTextFieldName.getText() ){
        errorMessage = "Name is not acceptable";
        this.jTextFieldNameActionPerformed(requestFocusInWindow());
}

The space after getText() in the first line is where I need to input a test but I can't find a way to do this that works. Can anyone help?

Check out the methods in the String API: http://docs.oracle.com/javase/7/docs/api/java/lang/String.html — Kevin Workman, Jan 23 '14 at 15:12

score 4 · Answer 1 · edited May 23 '17 at 11:49

4

The best way in swing is if you are using PlainDocument as document for your textComponent. It's to use a DocumentFilter. Take a look in how to do it in Text Component Features implementing a DocumentFilter. You have to override ìnsertString method then there you can use your regex. Here you have an example using DocumentFilter.

edited May 23 '17 at 11:49

Community

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answered Jan 23 '14 at 18:40

nachokk

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score 1 · Answer 2 · answered Jan 23 '14 at 15:13

1

Why not try with a regex?

else if(this.jTextFieldName.getText().matches(".*\\d+.*") ){

answered Jan 23 '14 at 15:13

AntonH

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score 0 · Answer 3 · answered Jan 23 '14 at 15:39

0

If you can then go for it

jTextField.addKeyListener(new KeyAdapter() {
    public void keyTyped(KeyEvent e) {
      char c = e.getKeyChar();
      if (!((c >= 'a') && (c <= 'z') || (c >= 'A') && (c <= 'Z') ||
         (c == KeyEvent.VK_BACK_SPACE) ||
         (c == KeyEvent.VK_DELETE))) {
        getToolkit().beep();
        //JOptionPane.showMessageDialog(rootPane, "Enter only Alphabets");
        e.consume();
      }
    }
  });

answered Jan 23 '14 at 15:39

ravibagul91

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Actually using a `keyListener` is not the proper way. – nachokk Jan 23 '14 at 18:42
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Don't use a `KeyListener` for a text field. The correct way is to use a `DocumentFilter` or even a `JFormattedTextField` – Paul Samsotha Jan 23 '14 at 18:43
@peeskillet Thank you, I will follow you next time. – ravibagul91 Jan 24 '14 at 04:55

score 0 · Answer 4 · edited Jan 23 '14 at 16:29

0

Try the regex ^[0-9]+$.

You can implement it like this:

this.jTextFieldName.getText().matches("^[0-9]+$")

edited Jan 23 '14 at 16:29

The Guy with The Hat

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answered Jan 23 '14 at 16:09

Nags

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Acoording to the question, _"they will **not** be able to input any numeric values"_ – The Guy with The Hat Jan 23 '14 at 16:35
Problem is that this matches only completely numerical answers. So "Abc123" doesn't match this pattern. Also would require a 'not ("!") at the beginning. – AntonH Jan 23 '14 at 16:58

How to prevent a user inputing numeric values

4 Answers4