SpringSparkFilter.java

    @Override
    protected SparkApplication getApplication(FilterConfig filterConfig) throws ServletException {
        Class<?>[] configClasses = getConfigClasses(filterConfig);
        try (AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(configClasses)) {
            String applicationClassName = filterConfig.getInitParameter(APPLICATION_CLASS_PARAM);

            try {
                return (SparkApplication) context.getBean(Class.forName(applicationClassName));
            } catch (ClassNotFoundException e) {
                throw new ServletException(e);
            }
        }
    }