1 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>StandardWrapperValve--->Servlet>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> 2 请求转出，都由valve来调用servlet的service方法 3 [1] 直接转出 4 StandardWrapperValve 5 void java.org.apache.catalina.core.StandardWrapperValve.invoke(Request request, Response response) throws IOException, ServletException 6 --->filterChain.doFilter 7 ------------>servlet.service(request, response); 8 9 [2] 内部循环再转出 10 -------->((AsyncContextImpl)request.getAsyncContext()).doInternalDispatch(); 11 ----> void java.org.apache.catalina.core.AsyncContextImpl.doInternalDispatch() throws ServletException, IOException 12 ----> 13 Runnable runnable = dispatch; 14 dispatch = null; 15 runnable.run(); 16 17 -------------> 18 void java.org.apache.catalina.core.AsyncContextImpl.dispatch(ServletContext context, String path) 19 ---->applicationDispatcher.dispatch(servletRequest, servletResponse); 20 21 22 AsyncDispatcher=applicationDispatcher 23 24 final class ApplicationDispatcher implements AsyncDispatcher, RequestDispatcher 25 26 ------>final class ApplicationDispatcher implements AsyncDispatcher, RequestDispatcher 27 ---------> void java.org.apache.catalina.core.ApplicationDispatcher.doDispatch(ServletRequest request, ServletResponse response) throws ServletException, IOException 28 -------------> void java.org.apache.catalina.core.ApplicationDispatcher.doDispatch(ServletRequest request, ServletResponse response) throws ServletException, IOException 29 //Servlet Service Method is called by the FilterChain 30 ----------->void java.org.apache.catalina.core.ApplicationFilterChain.doFilter(ServletRequest request, ServletResponse response) throws IOException, ServletException 31 --> void java.org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ServletRequest request, ServletResponse response) throws IOException, ServletException 32 ------------>servlet.service(request, response); 33 最终都是由servlet.service(request, response); 34 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>StandardWrapperValve--->Servlet>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> 35 36