1 /* 2 * $Id: ServletUtil.java 1375743 2012-08-21 20:05:58Z nlebas $ 3 * 4 * Licensed to the Apache Software Foundation (ASF) under one 5 * or more contributor license agreements. See the NOTICE file 6 * distributed with this work for additional information 7 * regarding copyright ownership. The ASF licenses this file 8 * to you under the Apache License, Version 2.0 (the 9 * "License"); you may not use this file except in compliance 10 * with the License. You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, 15 * software distributed under the License is distributed on an 16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 17 * KIND, either express or implied. See the License for the 18 * specific language governing permissions and limitations 19 * under the License. 20 */ 21 22 package org.apache.tiles.request.servlet; 23 24 import java.io.IOException; 25 26 import javax.servlet.ServletContext; 27 import javax.servlet.ServletException; 28 29 import org.apache.tiles.request.ApplicationContext; 30 import org.apache.tiles.request.ApplicationAccess; 31 import org.apache.tiles.request.RequestWrapper; 32 import org.apache.tiles.request.Request; 33 34 /** 35 * Utilities for Tiles request servlet support. 36 * 37 * @version $Rev: 1375743 $ $Date: 2012-08-22 06:05:58 +1000 (Wed, 22 Aug 2012) $ 38 */ 39 public final class ServletUtil { 40 41 /** 42 * Constructor. 43 */ 44 private ServletUtil() { 45 } 46 47 /** 48 * Wraps a ServletException to create an IOException with the root cause if present. 49 * 50 * @param ex The exception to wrap. 51 * @param message The message of the exception. 52 * @return The wrapped exception. 53 */ 54 public static IOException wrapServletException(ServletException ex, 55 String message) { 56 IOException retValue; 57 Throwable rootCause = ex.getRootCause(); 58 if (rootCause != null) { 59 // Replace the ServletException with an IOException, with the root 60 // cause of the first as the cause of the latter. 61 retValue = new IOException(message, rootCause); 62 } else { 63 retValue = new IOException(message, ex); 64 } 65 66 return retValue; 67 } 68 69 /** 70 * Returns the application context getting it from the servlet context. It must be 71 * first saved creating a {@link ServletApplicationContext} and using 72 * {@link ApplicationAccess#register(ApplicationContext)}. 73 * 74 * @param servletContext The servlet context. 75 * @return The application context, if found, <code>null</code> otherwise. 76 */ 77 public static ApplicationContext getApplicationContext(ServletContext servletContext) { 78 return (ApplicationContext) servletContext 79 .getAttribute(ApplicationAccess.APPLICATION_CONTEXT_ATTRIBUTE); 80 } 81 82 /** 83 * Opens a TilesRequestContext until it finds a ServletTilesRequestContext. 84 * 85 * @param request The request to open. 86 * @return The servlet-based request context. 87 * @throws NotAServletEnvironmentException If a servlet-based request 88 * context could not be found. 89 */ 90 public static ServletRequest getServletRequest(Request request) { 91 Request currentRequest = request; 92 while (true) { 93 if (currentRequest == null) { 94 throw new NotAServletEnvironmentException("Last Tiles request context is null"); 95 } 96 97 if (currentRequest instanceof ServletRequest) { 98 return (ServletRequest) currentRequest; 99 } 100 if (!(currentRequest instanceof RequestWrapper)) { 101 throw new NotAServletEnvironmentException("Not a Servlet environment, not supported"); 102 } 103 currentRequest = ((RequestWrapper) currentRequest).getWrappedRequest(); 104 } 105 } 106 107 /** 108 * Gets a servlet context from a TilesApplicationContext. 109 * 110 * @param applicationContext The application context to analyze. 111 * @return The servlet context. 112 * @throws NotAServletEnvironmentException If the application context is not 113 * servlet-based. 114 */ 115 public static ServletContext getServletContext(ApplicationContext applicationContext) { 116 if (applicationContext instanceof ServletApplicationContext) { 117 return (ServletContext) ((ServletApplicationContext) applicationContext).getContext(); 118 } 119 120 throw new NotAServletEnvironmentException("Not a Servlet-based environment"); 121 } 122 }