JoptionPane验证出现问题

我遇到的问题是这个代码:

       String birthString = JOptionPane.showInputDialog(
           null, "Enter birth year: ", "How long have you been alive?",
           JOptionPane.QUESTION_MESSAGE);      
   Pattern p = Pattern.compile("[A-Z,a-a,&%$#@!()*^]");
   Matcher m = p.matcher(birthString);
   if (m.find()){
       JOptionPane.showMessageDialog(null, 
             "That doesn't look like numbers to me... Try again.",
             "How long have you been alive?", JOptionPane.WARNING_MESSAGE);
   }      
   int birth = Integer.parseInt(birthString);
   String currentString = JOptionPane.showInputDialog(
           null, "Enter cureent year: ", "How long have you been alive?",
           JOptionPane.QUESTION_MESSAGE);
   int current = Integer.parseInt(currentString);
   Pattern c = Pattern.compile("[A-Z,a-a,&%$#@!()*^]");
   Matcher n = c.matcher(currentString);     
   if (n.find()){
       JOptionPane.showMessageDialog(null, 
             "That doesn't look like numbers to me... Try again.",
             "How long have you been alive?", JOptionPane.WARNING_MESSAGE);
   }

我想确保,如果有人输入了数字以外的任何东西,它会显示对话框消息“对我来说这不像数字…再试一次”。唯一的问题是它没有做到这一点,程序只是出错了。任何帮助都将不胜感激,我知道这是我做错的小事情,只是找不到。