struts2-流程详解-StrutsPrepareAndExecuteFilter

http://hi.baidu.com/liangzhongbo/item/07be3a560c16bc13da163536

org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter

初始化:

public void init(FilterConfig filterConfig)
throws ServletException
{
InitOperations init = new InitOperations();
FilterHostConfig config = new FilterHostConfig(filterConfig);
init.initLogging(config);
Dispatcher dispatcher = init.initDispatcher(config);
init.initStaticContentLoader(config, dispatcher);
prepare = new PrepareOperations(filterConfig.getServletContext(), dispatcher);
execute = new ExecuteOperations(filterConfig.getServletContext(), dispatcher);
excludedPatterns = init.buildExcludedPatternsList(dispatcher);
postInit(dispatcher, filterConfig);
init.cleanup();
break MISSING_BLOCK_LABEL_108;
Exception exception;
exception;
init.cleanup();
throw exception;
}

执行任务

public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)

throws IOException, ServletException
{
HttpServletRequest request;
HttpServletResponse response;
request = (HttpServletRequest)req;
response = (HttpServletResponse)res;
prepare.setEncodingAndLocale(request, response);

/*为当前线程创建ActionContext,ActionContext是ThreadLocal的，ActionContent其实就是一个线程安全的HashMap,它内部使用一个HashMap

来储存相关信息，这个map的构造是使用dispatcher.createContextMap(request, response, null, servletContext)来形成的，这个

map包括的信息有session,request,response，ServletContext，RequestMap，SessionMap等各种信息，可以通

个这个ActionContent取得各种信息，例如ActionContext.getContext().getSession()来获得当前的Session,

如果要获得request或者response必须用ServletActionContext它是ActionContent的子类，提供更多的方法，如

果是forward那也会新建一个新的ActionContent,这个新的ActionContent直接使用旧的ActionContent的数据来

构造*/

prepare.createActionContext(request, response);
prepare.assignDispatcherToThread();
if(excludedPatterns != null && prepare.isUrlExcluded(request, excludedPatterns))
{
chain.doFilter(request, response);
} else
{
request = prepare.wrapRequest(request);
org.apache.struts2.dispatcher.mapper.ActionMapping mapping = prepare.findActionMapping(request, response, true);
if(mapping == null)
{
boolean handled = execute.executeStaticResourceRequest(request, response);
if(!handled)
chain.doFilter(request, response);
} else
{
execute.executeAction(request, response, mapping);
}
}
prepare.cleanupRequest(request);
break MISSING_BLOCK_LABEL_178;
Exception exception;
exception;
prepare.cleanupRequest(request);
throw exception;
}