How to Make JTextField Accept Only Specific Numbers?

Question

Hello There
I've made 3 JTexfields That accepts only Numbers
But I Want To Make Them Accpets Numbers only from 1 to 12
and if the number is greater than 12 they don't accept it?
another Thing That I've Set Their Columns To 2 meaning that i want the user to enter only two numbers
but yet the user can enter many numbers how would i restrict entering numbers to only two numbers?
here's my code:
  import java.awt.*;
  import javax.swing.*;
  import javax.swing.text.*;
  public class ManyText extends JFrame{
       public static void main(String[]args){
       JTextField[ ] text = new JTextField[3];
       JButton button=new JButton("Press");
    for(int i = 0; i < text.length; i++)
     text[i] = new JTextField(3);
     for(int i = 0; i < text.length; i++){
     text.setColumns(2);     
text[i].setDocument(new PlainDocument(){
public void insertString(int offs, String str,
AttributeSet a) throws BadLocationException{
if("0123456789".indexOf(str) < 0)
java.awt.Toolkit.getDefaultToolkit().beep();
return;
super.insertString(offs, str, a);
     JFrame f=new JFrame();
     f.setSize(200,200);
     f.setLayout(new FlowLayout());
     f.add(text[0]);
f.add(text[1]);
f.add(text[2]);     
     f.setVisible(true);     

Answer 1

ejp wrote:
Actually I would suggest you're using the wrong control. I would use a JComboBox or a JSpinner for this.I suggested he use a JSpinner 1-2 threads ago. Maybe if he hears it enough, he'll believe it.