public static Properties loadFilterConfig() throws IOException {
    Properties filterProperties = new Properties();

    loadFilterConfig(filterProperties, ClassLoader.getSystemClassLoader());
    loadFilterConfig(filterProperties, FilterManager.class.getClassLoader());
    loadFilterConfig(filterProperties, Thread.currentThread().getContextClassLoader());
    loadFilterConfig(filterProperties, FilterManager.class.getClassLoader());

    return filterProperties;
}