public static void loadMappingProperties(URL u) throws IOException {
        logger.log(Level.FINE, "Loading mapping properties:{0}", u);
        InputStream in = u.openStream();
        try {
            Properties p = new Properties();
            p.load(in);
            addMappings(p);
        } finally {
            in.close();
        }
    }
Loads a set of compatibility mappings from the property file
specified by the given URL.

@param u the URL of the properties file (not null)
@throws IOException if an I/O exception occurs
jme3-core/src/main/java/com/jme3/input/JoystickCompatibilityMappings.java