1参考地址：The file cannot be validated as the host "struts.apache.org" is currently unreachable.
IDE:Eclipse 3.5
解决步骤如下：
Window-->Preferences-->XML-->XML Catalog-->Add...
Location:
x:\struts-1.3.10-all\struts-1.3.10\src\core\src\main\resources\org\apache\struts\resources\struts-config_1_3.dtd
Key Type:
Public ID
Key:
-//Apache Software Foundation//DTD Struts Configuration 1.3//EN
~Specify alternative web address
http://struts.apache.org/dtds/struts-config_1_3.dtd
为了避免看不懂，特上图