struts2-convention-plugin-2.1.6 jar 的作用

The struts2-convention-plugin-2.1.6 jar file is needed if your are using annotations.

The Convention plug-in is the one which does everything in the background. The Convention plug-in does the following things.

• By default the Convention plug-in looks for the action classes inside the following packages strut, struts2, action or actions . Here our package name is com.vaannila.action . Any package that matches these names will be considered as the root package for the Convention plug-in.
• The action class should either implement com.opensymphony.xwork2.Action interface or the name of the action class should end with Action . Here we extend our WelcomeUser class from com.opensymphony.xwork2.ActionSupport which inturn implements com.opensymphony.xwork2.Action.
• The Convention plug-in uses the action class name to map the action URL. Here our action class name is WelcomeUser and the URL is welcome-user . The plug-in converts the camel case class name to dashes to get the request URL.
• Now the Convention plug-in knows which Action class to call for a particular request. The next step is to find which result to forward based on the return value of the execute method. By default the Convention plug-in will look for result pages in WEB-INF/content directory.
• Now the Convention plug-in knows where to look for results, but it doesn't know which file to display inside the content directory. The Convention plug-in finds this with the help of the result code returned by the Action class. If "success " is returned then the Convention plug-in will look for a file name welcome-user-success.jsp or welcome-user.jsp . It need not be a jsp file it can be even a velocity or freemaker files. If the result value is "input" it will look for a file name welcome-user-input.jsp or welcome-user-input.vm or welcome-user-input.ftl.