Limit JTextField number of characters

[Wael Atef]

Hi all,
i want to limit the number of characters a JTextField can accept to maximum of 6 characters so that any characters typed by the user beyond these characters not shown in TextField. How can i petrform that.

[Abhik Sarkar]

You can use a javax.swing.InputVerifier to validate your JTextField.
Here is an example:

  
    JTextField tf = new JTextField(6);
    tf.setInputVerifier(new InputVerifier() {
      public boolean verify(JComponent input) {
        JTextField tField = (JTextField) input;
        return (tField.getText().trim().length() == 6);
      }
    });

[ June 16, 2003: Message edited by: Abhik Sarkar ]

[Soniya Ahuja]

Hello,

I tried the code sample given above. But it's not working . I'm working with JDK 5. I've added this text field to a jframe. Here's the code

JFrame frame = new JFrame("Java CrossWord");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container cpF = frame.getContentPane();

			JTextField jtf = new JTextField(6);
			jtf.setInputVerifier(new InputVerifier() {   
     				public boolean verify(JComponent input) {   
				        JTextField tField = (JTextField) input;   
				        return (tField.getText().trim().length() == 6);   
				 }   
			 });  

cpF.add(jtf);
//Display the window.
	
        frame.pack();
	
        frame.setVisible(true);

I am still able to type beyond 6 characters in the text field

[Maneesh Godbole]

Soniya,
In future, please start a new thread for your questions. Also, this particular thread is 6 years old.

The InputVerifier is not the correct solution. InputVerifier only ensures that the component will not loose focus in case the validation fails. It does not enforce the input conditions as you want.
This question comes up quite a few times and has been answered before. Search the forums.
The ranch Swing FAQ also has an article on numeric text fields with sample code. You can adapt the code to suit your requirements.