Custom spark filter with ServletContextListener implementation

CustomSparkFilter.java

@WebFilter(urlPatterns = {"/*"})
@WebListener
public class YourCustomFilter extends SparkFilter implements ServletContextListener {
    
    @Override
    protected SparkApplication getApplication(FilterConfig filterConfig) throws ServletException {
        return //your SparkApplication;
    }
    
    @Override
    public void contextInitialized(ServletContextEvent servletContextEvent) {
        //startup stuff
    }
    
    @Override
    public void contextDestroyed(ServletContextEvent servletContextEvent) {
        //shutdown stuff
    }
}