Web. XML <web-app> hints the content of element type "Web-app" must match "(icon?,display-name?,description?, Distributable?,

Error: When configuring Web. XML, a red fork appears, prompting

The content of element type "Web-app" must match "(icon?,display-
name?,description?,distributable?,context-param*,filter*,filter-mapping*,listener*,servlet*,servlet-
mapping*,session-config?,mime-mapping*,welcome-file-list?,error-page*,taglib*,resource-env-
ref*,resource-ref*,security-constraint*,login-config?,security-role*,env-entry*,ejb-ref*,ejb-local-ref*) ".
-No grammar constraints (DTD or XML Schema) detected for the document.

The reason is probably: the label order in Web. XML does not conform to the WEB-APP_2_3.DTD specification

Web. XML Header configuration:

<?xml version= "1.0" encoding= "UTF-8"?>
<! DOCTYPE Web-app Public "-//sun Microsystems, INC.//DTD Web Application 2.3//en" "Http://java.sun.com/dtd/web-app_2_3. DTD ">
<web-app>

Cause: The Document Content label order does not conform to the WEB-APP_2_3.DTD specification

Solution Solutions

1: Arranged in the order of the prompts

2: Delete <! DOCTYPE .... This content, namely <! DOCTYPE Web-app Public "-//sun Microsystems, INC.//DTD Web Application 2.3//en" "http://java.sun.com/dtd/web-app_2_ 3.DTD"> Delete this line

Web. xml <web-app> prompts the content of element type "Web-app" must match "(icon?,display-name?,description?, Distributable?,