I do not know if this will be of use to anyone but i thought i would just leave it here because i saw a thread where someone asked how to determine if more than one button on a mouse is being pressed and this code below checks to see if both the left button and right button are being pressed at the same time.
if((e.getModifierEx() & MouseEvent.BUTTON1_DOWN_MASK) != 0 && (e.getModifierEx() & (MouseEvent.BUTTON3_DOWN_MASk)) != 0)