JTextField limiting character amount input and accepting numeric only

Question

here\'s the code that i have on how to limit the character input length

class JTextFieldLimit extends PlainDocument {
  private int limit;
  // optional uppe         


        

Answer 1

    import java.awt.event.KeyAdapter;    
    import java.awt.event.KeyEvent;    
    import javax.swing.JTextField;        

    public class Validation {

         public static void validateInt(final JTextField txt){
            txt.addKeyListener(new KeyAdapter() {

                   @Override
                   public void keyTyped(KeyEvent e) {
                        char c = e.getKeyChar();
                        if ( ((c < '0') || (c > '9')) 
                             && (c != KeyEvent.VK_BACK_SPACE)) {
                        e.consume();  // ignore event
                   }
               }
            });
        }

        public static void validatelength(final JTextField txt,final int size){    
              txt.addKeyListener(new KeyAdapter() {

              @Override 
              public void keyTyped(KeyEvent e) {     
                  String text = txt.getText();  
                  int length = text.length();  
                  if (length == size) {  
                          e.consume();// ignore event  
                  }
              }   
        });
     }  
   }