java Expression too complex reduce the number of conditionl operators

Question

We have a program that we run against our code to adhere to some coding standards.

The program says:

Expression should not be too complex, reduce the number of conditional operators used int he expression Min allowed 3.

How can I reduce the number of conditional operators? perhaps put the keyevents in an array?

public boolean onlyNumbers(KeyEvent evt) {
    char c = evt.getKeyChar();
    boolean returnValue = true;
    if (
        !(
            Character.isDigit(c) 
            || c == KeyEvent.VK_BACK_SPACE
            || c == KeyEvent.VK_DELETE 
            || c == KeyEvent.VK_END 
            || c == KeyEvent.VK_HOME
        )
        || c == KeyEvent.VK_PAGE_UP
        || c == KeyEvent.VK_PAGE_DOWN
        || c == KeyEvent.VK_INSERT
    ) {
        evt.consume();
        returnValue = false;
    }
    return returnValue;
}

Answer 1

final String junkChars = new String(new char[] {
    KeyEvent.VK_BACK_SPACE,
    KeyEvent.VK_DELETE,
    KeyEvent.VK_END,
    KeyEvent.VK_HOME
    /* The last three seem unused in the latest version
    KeyEvent.VK_PAGE_UP,
    KeyEvent.VK_PAGE_DOWN,
    KeyEvent.VK_INSERT */
});
if(!Character.isDigit(c) && junkChars.indexOf(c) == -1) {
   evt.consume();
   return false;
}  else {
    return true;
}