Add a DTD to eclipse

Problem description:
The configuration file struts. xml to write struts2 is:
<? Xml version = "1.0" encoding = "UTF-8"?>
<! DOCTYPE struts PUBLIC
"-// Apache Software Foundation // DTD Struts Configuration 2.0 // EN"
Http://struts.apache.org/dtds/struts-2.0.dtd>
But no prompt Function

Steps:
1. Decompress struts-2.2.1 (compressed package)
2. Click apps to enter
3, click the struts2-blank-2.2.1.war open mode winRAR compressed file manager
4, click the WEB-INF to see lib, and then drag the lib out. Store in a path
For example, E: \ back up \ teacher \ day59 \ struts2 Documents \ struts-2.2.1 \ apps at any time
5, click this lib to enter unzip the xwork-core-2.2.1 compressed package
6. Click here to decompress the package and enter. You can see the xwork-2.0.dtd file.
For example: E: \ backup at any time \ teacher \ day59 \ struts2 material \ struts-2.2.1 \ apps \ lib \ xwork-core-2.2.1

Then click
Windows --> preferences --> Files and Editors --> XML Catalog --> Add

Location: equal to the path in Step 6
Key: equals-// Apache Software Foundation // DTD Struts Configuration 2.0 // EN
Click OK !!!!!!!!!!