1. <! -- Specify the default sequence set of the Web application, which is equivalent to calling the setCharacterEncoding method of HttpServletRequest -->
<Constant name = "struts. i18n. encoding" value = "UTF-8"/>
2. <! -- This attribute specifies the request suffix to be processed by Struts 2. The default value of this attribute is action, that is, all requests matching *. action are processed by Struts 2. If you need to specify multiple request suffixes, multiple suffixes are separated by commas (,). -->
<Constant name = "struts. action. extension" value = "do"/> (the Action class name is used when you directly access the methods in Ation! Method Name. do)
3. <! -- Set whether the browser caches static content. The default value is true (used in the production environment). It is best to disable it during development. -->
<Constant name = "struts. serve. static. browserCache" value = "false"/>
4. <! -- When the struts configuration file is modified, whether the system automatically reloads the file. The default value is false (used in the production environment). It is best to open the file during development. -->
<Constant name = "struts. configuration. xml. reload" value = "true"/>
5. <! -- Used in the startup mode to print more detailed error information -->
<Constant name = "struts. devMode" value = "true"/>
6. <! -- View topic recognized by the user -->
<Constant name = "struts. ui. theme" value = "simple"/>
7. <! -- This attribute specifies that the action in Struts 2 is created by the Spring container -->
<Constant name = "struts. objectFactory" value = "spring"/>