matching problem

[drgnfire25]

can someone please tell me what I am missing in this field cheker. I only want it to take numbers but it still takes letters

         gpaField.setColumns(4);
         String gpcheck = gpaField.getText();
             //float gpanum = Float.parseFloat(gpaField.getText());
             if (gpcheck.length()<= 0 || gpcheck.length()>=4 || gpcheck.matches("^([0-9]{0,1}[.]{1}[0-9]{3})")){
                        JOptionPane.showMessageDialog(null, "Please enter correct GPA");
                        gpaField.setBackground(Color.yellow);
                      IllegalArgumentException exception = new IllegalArgumentException("Invalid input");
                      throw exception;
                    }
             else {
                 gpaField.setBackground(new JTextField().getBackground());
             }

[Zack]

Your IF statement says:
"If the length is less than zero, or the length is greater than four, or it is a number with 3 decimal places, then it is invalid."

What you want it to say:
"If the length is less than zero, or the length is greater than four, or it is NOT a number with 3 decimal places, then it is invalid."

[drgnfire25]

so how do I say NOT I tried ! no luck and the Pattern (Java 2 Platform SE v1.4.2)
doesn't really specify a NOT

[Fubarable]

For NOT, use !. You've used ! in if statements before surely. And if it doesn't work, then we can't help you unless you post your attempt.

[drgnfire25]

sorry I got it... the ! was in the wrong spot. seam to be having a P.I.C.N.I.C. today