Java tutorial
/* * Copyright (c) 1998-2012 Caucho Technology -- all rights reserved * * This file is part of Resin(R) Open Source * * Each copy or derived work must preserve the copyright notice and this * notice unmodified. * * Resin Open Source is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * Resin Open Source is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty * of NON-INFRINGEMENT. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License * along with Resin Open Source; if not, write to the * * Free Software Foundation, Inc. * 59 Temple Place, Suite 330 * Boston, MA 02111-1307 USA * * @author Scott Ferguson */ package org.ireland.jnetty.webapp; import javax.servlet.*; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.ireland.jnetty.dispatch.HttpInvocation; import org.ireland.jnetty.http.HttpServletRequestImpl; import org.ireland.jnetty.http.HttpServletResponseImpl; import org.ireland.jnetty.http.wrapper.ErrorRequest; import org.ireland.jnetty.http.wrapper.ForwardRequest; import org.ireland.jnetty.http.wrapper.IncludeRequest; import java.io.IOException; import java.io.OutputStream; import java.io.PrintWriter; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * * ?,??RequestDispatcher * * ?rawContextURI??,?RequestDispatcherImpl, ??rawContextURI?RequestDispatcherImpl * * ??rawContextURI?(???),???,??? * * @author KEN * */ public class RequestDispatcherImpl implements RequestDispatcher { private final static Log log = LogFactory.getLog(RequestDispatcherImpl.class.getName()); static final int MAX_DEPTH = 64; // WebApp the request dispatcher was called from private final WebApp _webApp; private final String _rawContextURI; private HttpInvocation _dispatchInvocation; private HttpInvocation _forwardInvocation; private HttpInvocation _includeInvocation; private HttpInvocation _errorInvocation; // private HttpInvocation _asyncInvocation; public RequestDispatcherImpl(WebApp webApp, String rawContextURI) { _webApp = webApp; _rawContextURI = rawContextURI; } /** * This method sets the dispatcher type of the given request to DispatcherType.REQUEST. * * ,DispatcherType.REQUEST?. * * @param request * @param response * @throws ServletException * @throws IOException */ public void dispatch(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // jsp/15m8 if (response.isCommitted()) throw new IllegalStateException("dispatch() not allowed after buffer has committed."); // build invocation,if not exist if (_dispatchInvocation == null) { _dispatchInvocation = buildDispatchInvocation(_rawContextURI); } doDispatch(request, response, _dispatchInvocation); } private void doDispatch(HttpServletRequest request, HttpServletResponse response, HttpInvocation invocation) throws ServletException, IOException { // ,responsebuffer,TODO: need resetBuffer()? response.resetBuffer(); // Set the invocation into HttpServlerRequestImpl if (request instanceof HttpServletRequestImpl) { ((HttpServletRequestImpl) request).setInvocation(_dispatchInvocation); ((HttpServletRequestImpl) request).setDispatcherType(DispatcherType.REQUEST); } boolean isValid = false; try { invocation.getFilterChainInvocation().service(request, response); isValid = true; } finally { if (request.getAsyncContext() != null) { // An async request was started during the forward, don't close the // response as it may be written to during the async handling return; } // server/106r, ioc/0310 if (isValid) { finishResponse(response); } } } @Override public void forward(ServletRequest request, ServletResponse response) throws ServletException, IOException { // jsp/15m8 if (response.isCommitted()) throw new IllegalStateException("forward() not allowed after buffer has committed."); // build invocation,if not exist if (_forwardInvocation == null) { _forwardInvocation = buildForwardInvocation(_rawContextURI); } doForward((HttpServletRequest) request, (HttpServletResponse) response, _forwardInvocation); } private void doForward(HttpServletRequest request, HttpServletResponse response, HttpInvocation invocation) throws ServletException, IOException { // Reset any output that has been buffered, but keep headers/cookies response.resetBuffer(); // Servlet-3_1-PFD 9.4 //Wrap the request ForwardRequest wrequest = new ForwardRequest(request, response, invocation); // If we have already been forwarded previously, then keep using the established // original value. Otherwise, this is the first forward and we need to establish the values. // Note: the established value on the original request for pathInfo and // for queryString is allowed to be null, but cannot be null for the other values. if (request.getAttribute(RequestDispatcher.FORWARD_REQUEST_URI) == null) { // ??, wrequest.setAttribute(RequestDispatcher.FORWARD_REQUEST_URI, request.getRequestURI()); wrequest.setAttribute(RequestDispatcher.FORWARD_CONTEXT_PATH, request.getContextPath()); wrequest.setAttribute(RequestDispatcher.FORWARD_SERVLET_PATH, request.getServletPath()); wrequest.setAttribute(RequestDispatcher.FORWARD_PATH_INFO, request.getPathInfo()); wrequest.setAttribute(RequestDispatcher.FORWARD_QUERY_STRING, request.getQueryString()); } boolean isValid = false; try { invocation.getFilterChainInvocation().service(wrequest, response); isValid = true; } finally { if (request.getAsyncContext() != null) { // An async request was started during the forward, don't close the // response as it may be written to during the async handling return; } // server/106r, ioc/0310 if (isValid) { finishResponse(response); } } } @Override public void include(ServletRequest request, ServletResponse response) throws ServletException, IOException { // jsp/15m8 if (response.isCommitted()) throw new IllegalStateException("include() not allowed after buffer has committed."); // build invocation,if not exist if (_includeInvocation == null) { _includeInvocation = buildIncludeInvocation(_rawContextURI); } doInclude((HttpServletRequest) request, (HttpServletResponse) response, _forwardInvocation); } private void doInclude(HttpServletRequest request, HttpServletResponse response, HttpInvocation invocation) throws ServletException, IOException { //Wrap the request IncludeRequest wrequest = new IncludeRequest(request, response, invocation); // If we have already been include previously, then keep using the established // original value. Otherwise, this is the first include and we need to establish the values. // Note: the established value on the original request for pathInfo and // for queryString is allowed to be null, but cannot be null for the other values. if (request.getAttribute(RequestDispatcher.INCLUDE_REQUEST_URI) == null) { // ?Include, wrequest.setAttribute(RequestDispatcher.INCLUDE_REQUEST_URI, request.getRequestURI()); wrequest.setAttribute(RequestDispatcher.INCLUDE_CONTEXT_PATH, request.getContextPath()); wrequest.setAttribute(RequestDispatcher.INCLUDE_SERVLET_PATH, request.getServletPath()); wrequest.setAttribute(RequestDispatcher.INCLUDE_PATH_INFO, request.getPathInfo()); wrequest.setAttribute(RequestDispatcher.INCLUDE_QUERY_STRING, request.getQueryString()); } boolean isValid = false; try { invocation.getFilterChainInvocation().service(wrequest, response); isValid = true; } finally { if (request.getAsyncContext() != null) { // An async request was started during the forward, don't close the // response as it may be written to during the async handling return; } // server/106r, ioc/0310 if (isValid) { finishResponse(response); } } } /** * This method Wrap the dispatcher type of the given request to DispatcherType.ERROR. * * @param request * @param response * @throws ServletException * @throws IOException */ public void error(ServletRequest request, ServletResponse response) throws ServletException, IOException { // jsp/15m8 if (response.isCommitted()) throw new IllegalStateException("error() not allowed after buffer has committed."); // build invocation,if not exist if (_errorInvocation == null) { _errorInvocation = buildErrorInvocation(_rawContextURI); } doError((HttpServletRequest) request, (HttpServletResponse) response, _errorInvocation); } private void doError(HttpServletRequest request, HttpServletResponse response, HttpInvocation invocation) throws ServletException, IOException { // Reset any output that has been buffered, but keep headers/cookies response.resetBuffer(); // Servlet-3_1-PFD 9.4 //Wrap the request ErrorRequest wrequest = new ErrorRequest(request, response, invocation); boolean isValid = false; try { invocation.getFilterChainInvocation().service(wrequest, response); isValid = true; } finally { if (request.getAsyncContext() != null) { // An async request was started during the forward, don't close the // response as it may be written to during the async handling return; } // server/106r, ioc/0310 if (isValid) { finishResponse(response); } } } // ----------------------------------------------------------------------------------- /** * Fills the invocation with uri. * * @throws IOException */ private HttpInvocation buildDispatchInvocation(String rawContextURI) throws ServletException { return _webApp.buildDispatchInvocation(rawContextURI); } /** * Fills the invocation for a forward request. * * @throws IOException */ private HttpInvocation buildForwardInvocation(String rawContextURI) throws ServletException { return _webApp.buildForwardInvocation(rawContextURI); } /** * Fills the invocation for an include request. * * @throws IOException */ private HttpInvocation buildIncludeInvocation(String rawContextURI) throws ServletException { return _webApp.buildIncludeInvocation(rawContextURI); } /** * Fills the invocation for an error request. * * @throws IOException */ private HttpInvocation buildErrorInvocation(String rawContextURI) throws ServletException { return _webApp.buildErrorInvocation(rawContextURI); } // ------------------------------------------------------------------------------------ private void finishResponse(ServletResponse res) throws ServletException, IOException { if (res instanceof HttpServletResponseImpl) { res.flushBuffer(); // we sure that all data has already put to the ByteBuf? } else { try { OutputStream os = res.getOutputStream(); os.flush(); // os.close(); } catch (Exception e) { } try { PrintWriter out = res.getWriter(); out.flush(); // out.close(); } catch (Exception e) { } } } @Override public String toString() { return (getClass().getSimpleName() + "[" + _dispatchInvocation.getRawContextURI() + "]"); } // Util------------------------------------------------------------ /** * reques,ServletRequest * * @param request * @return */ private static ServletRequest unwarp(ServletRequest request) { ServletRequest _request = request; while (_request instanceof ServletRequestWrapper) { _request = ((ServletRequestWrapper) _request).getRequest(); } return _request; } /** * response,ServletResponse * * @param response * @return */ private static ServletResponse unwarp(ServletResponse response) { ServletResponse _response = response; while (_response instanceof ServletResponseWrapper) { _response = ((ServletResponseWrapper) _response).getResponse(); } return _response; } }