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1 /* 2 * ==================================================================== 3 * 4 * The Apache Software License, Version 1.1 5 * 6 * Copyright (c) 2001-2002 The Apache Software Foundation. All rights 7 * reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. The end-user documentation included with the redistribution, if 22 * any, must include the following acknowlegement: 23 * "This product includes software developed by the 24 * Apache Software Foundation (http://www.apache.org/)." 25 * Alternately, this acknowlegement may appear in the software itself, 26 * if and wherever such third-party acknowlegements normally appear. 27 * 28 * 4. The names "The Jakarta Project", "Stronghold" and "Apache Software 29 * Foundation" must not be used to endorse or promote products 30 * derived from this software without prior written permission. For 31 * written permission, please contact apache@apache.org. 32 * 33 * 5. Products derived from this software may not be called "Apache" 34 * nor may "Apache" appear in their names without prior written 35 * permission of the Apache Group. 36 * 37 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 38 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 39 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 40 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 41 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 43 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 44 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 45 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 46 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 47 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 48 * SUCH DAMAGE. 49 * ==================================================================== 50 * 51 * This software consists of voluntary contributions made by many 52 * individuals on behalf of the Apache Software Foundation. For more 53 * information on the Apache Software Foundation, please see 54 * <http://www.apache.org/>;. 55 * 56 */ 57 package org.apache.sesame.filter; 58 59 import org.apache.sesame.model.Request; 60 import org.apache.sesame.exception.MissingDataServletException; 61 62 import javax.servlet.Filter; 63 import javax.servlet.FilterConfig; 64 import javax.servlet.ServletException; 65 import javax.servlet.ServletRequest; 66 import javax.servlet.ServletResponse; 67 import javax.servlet.FilterChain; 68 import java.io.IOException; 69 70 /*** 71 * Base Filter class for all Sesame Filters. It provides common helper methods 72 * such as easy access to model objects. 73 * 74 * @author <a href="mailto:vmassol@apache.org">Vincent Massol</a> 75 * 76 * @version $Id: AbstractFilter.java,v 1.4 2002/06/03 18:18:51 vmassol Exp $ 77 */ 78 public abstract class AbstractFilter implements Filter 79 { 80 /*** 81 * Name under which the @{link Request} object is stored as an HTTP 82 * attribute. 83 */ 84 private static final String HTTP_REQUEST_ATTRIBUTE = 85 "sesame.application.request"; 86 87 /*** 88 * The filter configuration object. 89 */ 90 private FilterConfig config; 91 92 /*** 93 * @see Filter#init(FilterConfig) 94 */ 95 public void init(FilterConfig filterConfig) throws ServletException 96 { 97 this.config = filterConfig; 98 } 99 100 /*** 101 * @see Filter#destroy() 102 */ 103 public void destroy() 104 { 105 } 106 107 /*** 108 * All Sesame filters must implement this method. This is where their 109 * execution code is placed. This is equivalent to the filter 110 * <code>doFilter</code> method but has been renamed so that this 111 * <code>AbstractFilter</code> filter can wrap it and perform additionnal 112 * actions such as managing exceptions and logging them, etc. 113 * 114 * @param servletRequest the incoming servlet request 115 * @param servletResponse the outgoing servelt response to send back 116 * @param filterChain the filter chain 117 * @throws IOException if an error occurs 118 * @throws ServletException if an error occurs 119 */ 120 public abstract void execute(ServletRequest servletRequest, 121 ServletResponse servletResponse, FilterChain filterChain) 122 throws IOException, ServletException; 123 124 /*** 125 * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain) 126 */ 127 public void doFilter(ServletRequest servletRequest, 128 ServletResponse servletResponse, FilterChain filterChain) 129 throws IOException, ServletException 130 { 131 // Call the filter execute method and handle error conditions 132 try 133 { 134 execute(servletRequest, servletResponse, filterChain); 135 } 136 catch (MissingDataServletException e) 137 { 138 // TODO: log the exception here 139 throw e; 140 } 141 } 142 143 /*** 144 * @param servletRequest the Servlet request 145 * @return the application {@link Request} object 146 * @throws ServletException if an error occurs 147 */ 148 public Request getApplicationRequest(ServletRequest servletRequest) 149 throws ServletException 150 { 151 Request request = 152 (Request) servletRequest.getAttribute(HTTP_REQUEST_ATTRIBUTE); 153 154 if (request == null) 155 { 156 throw new MissingDataServletException("Cannot find attribute [" + 157 HTTP_REQUEST_ATTRIBUTE + "] in HTTP request"); 158 } 159 160 return request; 161 } 162 163 /*** 164 * @return the filter config object 165 */ 166 public FilterConfig getFilterConfig() 167 { 168 return this.config; 169 } 170 }

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