struts -执行流程

• When a client request is given, a web container will receive request
• Web container loads web.xml and verifies whether the url-patterns are verified or not, if matches web-container transfer the request to FilterDispatcher
• FilterDispatcher hand overs the request to ActionProxy, it is a proxy class which is responsible to apply before and after services to original business logic
• ActionProxy contacts ConfiguraionManager class, to know the suitable Action for the request and the needed services for the request
• ConfigurationManager class loads structs.xml and provides the required information back to ActionProxy
• ActionPorxy delegates the request along with its information to ActionInvocation
• ActionInvocation executes the interceptors added to an Action from 1 – N, after that it will call the business logic implemented from N – 1 in reverse order
• ActionInvocation receives finally result produced by an action aclass
• ActionProxy transfers the result back to FilterDispatcher
• FilterDispatcher selects an appropriate view, basing on the result
• Finally FilterDispatcher uses RequestDispatchers forwarding mechanism and forward a view as a response back to the client