JFinal源码导读第五天(2)doFilter中的ActionHandler详解

为什么80%的码农都做不了架构师&＃xff1f;>>>

1.我先贴上doFilter所有代码

public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {HttpServletRequest request &＃61; (HttpServletRequest)req;HttpServletResponse response &＃61; (HttpServletResponse)res;request.setCharacterEncoding(encoding);String target &＃61; request.getRequestURI();if (contextPathLength !&＃61; 0)target &＃61; target.substring(contextPathLength);boolean[] isHandled &＃61; {false};try {handler.handle(target, request, response, isHandled);}catch (Exception e) {if (log.isErrorEnabled()) {String qs &＃61; request.getQueryString();log.error(qs &＃61;&＃61; null ? target : target &＃43; "?" &＃43; qs, e);}}if (isHandled[0] &＃61;&＃61; false)chain.doFilter(request, response);} 2.String target &＃61; request.getRequestURI();
if (contextPathLength !&＃61; 0)
target &＃61; target.substring(contextPathLength);
这两段代码其实就是取出contextPath 留下真是的URI路径
3.handler.handle(target, request, response, isHandled);

4.假如没有配置自己handler那就执行最后面actionHandler

public final void handle(String target, HttpServletRequest request, HttpServletResponse response, boolean[] isHandled) {if (target.indexOf(".") !&＃61; -1) {return ;}isHandled[0] &＃61; true;String[] urlPara &＃61; {null};Action action &＃61; actionMapping.getAction(target, urlPara);if (action &＃61;&＃61; null) {if (log.isWarnEnabled()) {String qs &＃61; request.getQueryString();log.warn("Action not found: " &＃43; (qs &＃61;&＃61; null ? target : target &＃43; "?" &＃43; qs));}renderFactory.getErrorRender(404).setContext(request, response).render();return ;}try {Controller controller &＃61; action.getControllerClass().newInstance();controller.init(request, response, urlPara[0]);if (devMode) {boolean isMultipartRequest &＃61; ActionReporter.reportCommonRequest(controller, action);new ActionInvocation(action, controller).invoke();if (isMultipartRequest) ActionReporter.reportMultipartRequest(controller, action);}else {new ActionInvocation(action, controller).invoke();}Render render &＃61; controller.getRender();if (render instanceof ActionRender) {String actionUrl &＃61; ((ActionRender)render).getActionUrl();if (target.equals(actionUrl))throw new RuntimeException("The forward action url is the same as before.");elsehandle(actionUrl, request, response, isHandled);return ;}if (render &＃61;&＃61; null)render &＃61; renderFactory.getDefaultRender(action.getViewPath() &＃43; action.getMethodName());render.setContext(request, response, action.getViewPath()).render();}catch (RenderException e) {if (log.isErrorEnabled()) {String qs &＃61; request.getQueryString();log.error(qs &＃61;&＃61; null ? target : target &＃43; "?" &＃43; qs, e);}}catch (ActionException e) {int errorCode &＃61; e.getErrorCode();if (errorCode &＃61;&＃61; 404) {if (log.isWarnEnabled()) {String qs &＃61; request.getQueryString();log.warn("404 Not Found: " &＃43; (qs &＃61;&＃61; null ? target : target &＃43; "?" &＃43; qs));}e.getErrorRender().setContext(request, response).render();}else if (errorCode &＃61;&＃61; 401) {if (log.isWarnEnabled()) {String qs &＃61; request.getQueryString();log.warn("401 Unauthorized: " &＃43; (qs &＃61;&＃61; null ? target : target &＃43; "?" &＃43; qs));}e.getErrorRender().setContext(request, response).render();}else if (errorCode &＃61;&＃61; 403) {if (log.isWarnEnabled()) {String qs &＃61; request.getQueryString();log.warn("403 Forbidden: " &＃43; (qs &＃61;&＃61; null ? target : target &＃43; "?" &＃43; qs));}e.getErrorRender().setContext(request, response).render();}else {if (log.isErrorEnabled()) {String qs &＃61; request.getQueryString();log.error(qs &＃61;&＃61; null ? target : target &＃43; "?" &＃43; qs, e);}e.getErrorRender().setContext(request, response).render();}}catch (Exception e) {if (log.isErrorEnabled()) {String qs &＃61; request.getQueryString();log.error(qs &＃61;&＃61; null ? target : target &＃43; "?" &＃43; qs, e);}renderFactory.getErrorRender(500).setContext(request, response).render();}} 5.if (target.indexOf(".") !&＃61; -1) {
return ;

}
这几句代码的作用主要就是过滤css,img之类的,让filter不要对它起作用
6.Action action &＃61; actionMapping.getAction(target, urlPara);

/*** Support four types of url* 1: http://abc.com/controllerKey ---> 00* 2: http://abc.com/controllerKey/para ---> 01* 3: http://abc.com/controllerKey/method ---> 10* 4: http://abc.com/controllerKey/method/para ---> 11*/Action getAction(String url, String[] urlPara) {Action action &＃61; mapping.get(url);if (action !&＃61; null) {return action;}// --------int i &＃61; url.lastIndexOf(SLASH);if (i !&＃61; -1) {action &＃61; mapping.get(url.substring(0, i));urlPara[0] &＃61; url.substring(i &＃43; 1);}return action;} 7. actionMapping我前面已经介绍过啦,在我们的例子里面的值如下&＃xff1a;

如果是save方法&＃xff1a; controllerKey &＃61; /blog ,actionKey &＃61; /blog/save,controllerClass &＃61; BlogController.class,methodName &＃61; save, 同理如果是index()方法&＃xff1a; controllerKey&＃61;/blog,actionKey&＃61;/blog,controllerClass&＃61;BlogController.class,methodName &＃61;index 同理如果是add()方法&＃xff1a; controllerKey&＃61;/blog,actionKey&＃61;/blog/add,controllerClass&＃61;BlogController.class,methodName&＃61;add 同理如果是edit()方法&＃xff1a; controllerKey&＃61;/blog,actionKey&＃61;/blog/edit,controllerClass&＃61; BlogController.class,methodName&＃61;edit 同理如果是update()方法&＃xff1a; controllerKey&＃61;/blog,actionKey&＃61;/blog/update,controllerClass&＃61; BlogController.class,methodName&＃61;update 同理如果是delete()方法&＃xff1a; controllerKey&＃61;/blog,actionKey&＃61;/blog/delete,controllerClass&＃61; BlogController.class,methodName&＃61;delete 6. String controllerKey &＃61;entry.getKey();还有在我们中的例子为CommonController中的/ 只有1个index方法 controllcontrollerKey&＃61;/,actionKey&＃61;/,controllerClass&＃61;CommonController.class,methodName &＃61;index 7.我们的入口是actionKey&＃61;&＃39;/&＃39;
Controller controller &＃61; action.getControllerClass().newInstance(); // 这句话就可以解释Controller为什么的线程安全的,因为每次都实例化一个新的出来
在我们例子当中是CommonController
controller.init(request, response, urlPara[0]);urlPara就是参数

void init(HttpServletRequest request, HttpServletResponse response, String urlPara) {this.request &＃61; request;this.response &＃61; response;this.urlPara &＃61; urlPara;} 8. ActionReporter.reportCommonRequest(controller, action) 这个就是打印控制台信息的

JFinal action report -------- 2013-06-21 15:13:48 ------------------------------ Controller : com.demo.common.CommonController.(CommonController.java:1) Method : index Interceptor : com.demo.blog.BlogInterceptor1.(BlogInterceptor1.java:1)com.demo.blog.BlogInterceptor2.(BlogInterceptor2.java:1) -------------------------------------------------------------------------------- 9. 这句话是 new ActionInvocation(action, controller).invoke();
就是这里的核心代码&＃xff0c;本质就是调用递归调用拦截器

ActionInvocation(Action action, Controller controller) {this.controller &＃61; controller;this.inters &＃61; action.getInterceptors();this.action &＃61; action;} 10.下面的代码就是上面代码的核心

/*** Invoke the action.*/public void invoke() {if (index 这张图片就是上面代码执行的核心,也是拦截器的核心

Before invoking BlogInterceptor1/ Before invoking BlogInterceptor2/ 执行CommonController里面index方法 After invoking BlogInterceptor2/ After invoking BlogInterceptor1/ 11.Render render &＃61; controller.getRender(); 就是上面所说的FreeMarkerRenderFactory. getRender() 12.render.setContext(request, response, action.getViewPath()).render();

public void render() {response.setContentType(contentType);Enumeration attrs &＃61; request.getAttributeNames();Map root &＃61; new HashMap();while (attrs.hasMoreElements()) {String attrName &＃61; attrs.nextElement();root.put(attrName, request.getAttribute(attrName));}PrintWriter writer &＃61; null;try {Template template &＃61; config.getTemplate(view);writer &＃61; response.getWriter();template.process(root, writer); // Merge the data-model and the template} catch (Exception e) {throw new RenderException(e);}finally {if (writer !&＃61; null)writer.close();}} 一个流程完全结束下面,下一个阶段我会介绍数据库方面的啦,最后我会扩展权限功能.....