Exception in thread "main" java.lang.RuntimeException: WEB-INF directory not found.
    at com.jfinal.server.jetty.ServerFactory.detectWebAppDir(ServerFactory.java:76)
    at com.jfinal.server.jetty.ServerFactory.getServer(ServerFactory.java:65)
    at com.jfinal.core.JFinal.main(JFinal.java:196)