webwork源代码解读

今天大致的看了下webwork2.2.4的几个核心的类，做个总结 ：）

首先来看WebWork2.2.4.怎么分离HTTP请求,其实他是通过ServletDispatcher来达到目的.代码如下所示:
在ServletDispatcher里service方法的代码实现如下

java 代码

DispatcherUtils du = DispatcherUtils.getInstance();
      du.prepare(request, response);

      try {
          request = du.wrapRequest(request, getServletContext());
      } catch (IOException e) {
          String message = "Could not wrap servlet request with MultipartRequestWrapper!";
          LOG.error(message, e);
          throw new ServletException(message, e);
      }

      ActionMapping mapping = ActionMapperFactory.getMapper().getMapping(request);
      if (mapping == null) {
          try {
              response.sendError(404);
          } catch (IOException e) {
              LOG.error("Could not send 404 after not finding any ActionMapping", e);
          }
          return;
      }

      du.serviceAction(request, response, getServletContext(), mapping);

最后一句进行了相应的处理，在DispatcherUtils 处理代码如下：

java 代码

public HashMap createContextMap(Map requestMap,
                                   Map parameterMap,
                                   Map sessionMap,
                                   Map applicationMap,
                                   HttpServletRequest request,
                                   HttpServletResponse response,
                                   ServletContext servletContext) {
       HashMap extraContext = new HashMap();
       extraContext.put(ActionContext.PARAMETERS, new HashMap(parameterMap));
        //存放SessionMap,即对HttpSession封装后的map
        extraContext.put(ActionContext.SESSION, sessionMap);
              //存放applicationMap,即对Application封装后的map
       extraContext.put(ActionContext.APPLICATION, applicationMap);

       Locale locale = null;
       if (Configuration.isSet(WebWorkConstants.WEBWORK_LOCALE)) {
           locale = LocalizedTextUtil.localeFromString(Configuration.getString(WebWorkConstants.WEBWORK_LOCALE), request.getLocale());
       } else {
           locale = request.getLocale();
       }

       extraContext.put(ActionContext.LOCALE, locale);
       extraContext.put(ActionContext.DEV_MODE, Boolean.valueOf(devMode));

       extraContext.put(WebWorkStatics.HTTP_REQUEST, request);//存放HttpServletRequest
       extraContext.put(WebWorkStatics.HTTP_RESPONSE, response);
       extraContext.put(WebWorkStatics.SERVLET_CONTEXT, servletContext);
       extraContext.put(ComponentInterceptor.COMPONENT_MANAGER, request.getAttribute(ComponentManager.COMPONENT_MANAGER_KEY));

       // helpers to get access to request/session/application scope
       extraContext.put("request", requestMap);//存放RequestMap
       extraContext.put("session", sessionMap);
       extraContext.put("application", applicationMap);
       extraContext.put("parameters", parameterMap);

       AttributeMap attrMap = new AttributeMap(extraContext);
       extraContext.put("attr", attrMap);

       return extraContext;

对于HttpSession ,HttpServletRequest...等，webwork进行了相应的封装SessionMap,RequestMap..我们很容易通过它们来操作底层的HttpSession....

在ActionContext 里提供了~getSession()来获取的当前的SessionMap,对SessionMap的操作即是主要对HttpSession的操作，SesionMap的部分代码如下：

java 代码

 1.  public Object get(Object key) {
 2. if (session == null) { //这里的session即是HttpSession
 3. return null;
 4. }
 5.

 6. synchronized (session) {
 7. return session.getAttribute(key.toString());
 8. }
 9. }
10.

11. /**
12. * Saves an attribute in the session.
13. *
14. * @param key the name of the session attribute.
15. * @param value the value to set.
16. * @return the object that was just set.
17. */
18. public Object put(Object key, Object value) {
19. synchronized (this) {
20. if (session == null) {
21. session = request.getSession(true);
22. }
23. }
24.

25. synchronized (session) {
26. entries = null;
27. session.setAttribute(key.toString(), value);
28.

29. return get(key);
30. }
31. }
32.

对于ServletActionContext，继承ActionContext而来，主要提供了getRequest(),getResponse()等方法来对HttpServletRequest,HttpServletResponse进行操作，可以getRequest().getSession()来获取的HttpSession, 也可以通过 getServletContext() 来获得Servlet 的上下文。

：）