protected static Map<String, String> getButtonMappings(String joystickName, boolean create) {
        Map<String, String> result = buttonMappings.get(joystickName.trim());
        if (result == null && create) {
            result = new HashMap<String, String>();
            buttonMappings.put(joystickName.trim(), result);
        }
        return result;
    }
Obtains mappings specific to the joystick buttons

@param joystickName - The name of the joystick type to obtain mappings for.
@param create       - If there are no mappings present and this parameter is true, then a new entry for this joystick is created.
@return The various button remappings for the requested joystick, or null of there are none.
jme3-core/src/main/java/com/jme3/input/JoystickCompatibilityMappings.java