【文章內(nèi)容簡介】 n the springs. 2. Parent Child: we can define hierarchy like parent child. 3. Parent Child Sub Child Relationship: in this we can define hierarchy for 3 or more classes. 6. Autowiring: Autowiring is used to map the property name, values in xml file with java file. There are four types to integrate it. byName, byType, constructor, autodetect. If nothing is defined about it then byName is the default. Spring Web MVC Framework for rapid open source J2EE application development: a case study 3 7. Scope of Beans: All beans defined in spring are having scope of four values prototype, session, request, singleton,globalsession. This is used to control the access of the beans. 8. Reference Beans: One bean in the xml file can be assigned values from the other bean. This is used to read values from one bean and assign to another bean. II. MAJOR SPRING COMPONENTS In the spring we also follow the principals of the MVC. It has been designed more for the desktop and inter based applications. Spring consist of three core collaborating ponents. 1. Controller: Handles navigation logic and interacts with the Service tier for business logic2. Model: The contract between the Controller and the View Contains the data needed to render the View Populated by the Controller 3. View: Renders the response to the request Pulls data from the model. Core ponents in the spring MVC are as follows. 1. DispatcherServlet: this is the spring’s front controller implementation. receives the request and transfer it to the DispatchServlet. This is the first controller which interacts to the requests. It is also known as implementation of the Servlet. It controls the plete flow of the application and navigates the flow of application. 2. Controller: this is the user created ponent for handling requests. It encapsulates the navigation logic with it. Controller delegates the services for the service object. 3. View: view is responsible for rendering output. Different views can be selected for the different types of output bases on the results and the viewing device, munication devices. 4. ModelAndView: ModelAndView is the core part of the spring framework. It implements the business logic of the application. It is created by the controller. It associates the view to the request. It stores the business logic and Model data. A controller calls it and it will execute. On execution it will return the data and name of view. 5. ViewResolver: How the output is to be displayed depends on the result received from ModelAndView. It is used to map logical view names to actual view implementations. This part identifies and implement what is the output media and how to display it. 6. HandlerMapping: Strategy interface used by DispatcherServlet for mapping ining requests to individual Controllers. It identifies the request and calls the respective handler to provide the services. Handler will call to controller. Spring Web MVC Framework for rapid open source J2EE application development: a case study 4 III. SPRING ARCHITECTURE The Spring framework provides a fullfeatured MVC module for building Web applications. with spring’s pluggable MVC architecture. It is configurable with multiple view technologies Ex Java Server Pages, Velocity, Tiles, iText etc. Spring MVC separates the roles of the controller, model object, dispatcher Servlet and the handler object. Clear separation of objects and controllers makes them easier to customize. The figure 01 shows the view of the execution flow. Figure 01 The following figure 02 shows the sequence diagram of the spring model. In this the dispatcher Servlet is the entry point for the application. As soon the Dispatch Servlet get the request for the services and it will decides the handlers are mapped with the Servlet. Handler will e in action and will call the respective controller and the pass the request parameters to controller es in action, it contains business logic and a ModelAndView is associated with the controller. On execution it will return the ModelAndView to the Dispatch Servlet. This ModelAndView contains the data and view Servlet gets the ModelAndView from the controller. It contains the data and view name. Servlet will call the view resolver. View resolver will identify the name of the view through which data is to be presented. Finally it will present the Spring Web MVC Framework for rapid open source J2EE application development: a case study 5 data to the respective and appropriate format to the user. Figure 2： the sequence diagram of the spring model IV. SPRING AND XML Xml is widely used in the spring framework. It simplify the development process and saves time. xml is used to store the data, which is used during the execution of application. is the entry point in the application. It will tell you the further path of navigation. It loads the application context class and the tells the name of the dispatcher Servlet xml file. : ?xml version= encoding=UTF8? webapp version= xmlns=// xmlns:xsi= xsi:schemalLocation= Spring Web MVC Framework for rapid open source J2EE application development: a case study 6 listenerlistenerClass/listenerClass/listener servlet servletnamedispatcher/servletnameservletclass /servletclass loadonstartup1/loadonstartup /servlet servletmapping servletnamedispatcher/servletname urlpattern/send/*/urlpattern /servletmapping welefilelist welefile/welefile /welefilelis