src/web/org/codehaus/groovy/grails/web/servlet/mvc/GrailsWebRequestFilter.java

   1 /*
   2  * Copyright 2004-2005 the original author or authors.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package org.codehaus.groovy.grails.web.servlet.mvc;
  17
  18 import org.codehaus.groovy.grails.web.servlet.FlashScope;
  19 import org.codehaus.groovy.grails.web.util.WebUtils;
  20 import org.springframework.context.ApplicationContext;
  21 import org.springframework.context.i18n.LocaleContextHolder;
  22 import org.springframework.web.context.support.WebApplicationContextUtils;
  23 import org.springframework.web.filter.OncePerRequestFilter;
  24
  25 import javax.servlet.FilterChain;
  26 import javax.servlet.ServletException;
  27 import javax.servlet.http.HttpServletRequest;
  28 import javax.servlet.http.HttpServletResponse;
  29 import java.io.IOException;
  30
  31 /**
  32  * A filter that binds a GrailsWebRequest to the currently executing thread
  33  *
  34  * @author Graeme Rocher
  35  * @since 0.4
  36  *
  37  */
  38 public class GrailsWebRequestFilter extends OncePerRequestFilter {
  39
  40         /* (non-Javadoc)
  41          * @see org.springframework.web.filter.OncePerRequestFilter#doFilterInternal(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, javax.servlet.FilterChain)
  42          */
  43         protected void doFilterInternal(
  44                         HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
  45                         throws ServletException, IOException {
  46
  47                 LocaleContextHolder.setLocale(request.getLocale());
  48                 GrailsWebRequest webRequest = new GrailsWebRequest(request, response, getServletContext());
  49         configureParameterCreationListeners(webRequest);
  50
  51                 if (logger.isDebugEnabled()) {
  52                         logger.debug("Bound Grails request context to thread: " + request);
  53                 }
  54                 try {
  55             WebUtils.storeGrailsWebRequest(webRequest);
  56
  57             // Set the flash scope instance to its next state. We do
  58             // this here so that the flash is available from Grails
  59             // filters in a valid state.
  60             FlashScope fs = webRequest.getAttributes().getFlashScope(request);
  61             fs.next();
  62
  63             // Pass control on to the next filter (or the servlet if
  64             // there are no more filters in the chain).
  65             filterChain.doFilter(request, response);
  66                 }
  67                 finally {
  68                         webRequest.requestCompleted();
  69             WebUtils.clearGrailsWebRequest();
  70             LocaleContextHolder.setLocale(null);
  71                         if (logger.isDebugEnabled()) {
  72                                 logger.debug("Cleared Grails thread-bound request context: " + request);
  73                         }
  74                 }
  75         }
  76
  77     private void configureParameterCreationListeners(GrailsWebRequest webRequest) {
  78         ApplicationContext appCtx = WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext());
  79         String[] paramListenerBeans = appCtx.getBeanNamesForType(ParameterCreationListener.class);
  80         for (int i = 0; i < paramListenerBeans.length; i++) {
  81             ParameterCreationListener creationListenerBean = (ParameterCreationListener)appCtx.getBean(paramListenerBeans[i]);
  82             webRequest.addParameterListener(creationListenerBean);
  83         }
  84     }
  85
  86 }