001    /**
002     * Copyright (c) 2000-2010 Liferay, Inc. All rights reserved.
003     *
004     * This library is free software; you can redistribute it and/or modify it under
005     * the terms of the GNU Lesser General Public License as published by the Free
006     * Software Foundation; either version 2.1 of the License, or (at your option)
007     * any later version.
008     *
009     * This library is distributed in the hope that it will be useful, but WITHOUT
010     * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
011     * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
012     * details.
013     */
014    
015    package com.liferay.portal.servlet.filters.validhtml;
016    
017    import com.liferay.portal.kernel.log.Log;
018    import com.liferay.portal.kernel.log.LogFactoryUtil;
019    import com.liferay.portal.kernel.servlet.StringServletResponse;
020    import com.liferay.portal.kernel.util.ContentTypes;
021    import com.liferay.portal.kernel.util.HttpUtil;
022    import com.liferay.portal.kernel.util.StringPool;
023    import com.liferay.portal.kernel.util.StringUtil;
024    import com.liferay.portal.servlet.filters.BasePortalFilter;
025    import com.liferay.util.servlet.ServletResponseUtil;
026    
027    import javax.servlet.FilterChain;
028    import javax.servlet.http.HttpServletRequest;
029    import javax.servlet.http.HttpServletResponse;
030    
031    /**
032     * @author Julio Camarero
033     * @author Brian Wing Shun Chan
034     * @author Shuyang Zhou
035     */
036    public class ValidHtmlFilter extends BasePortalFilter {
037    
038            public static final String SKIP_FILTER =
039                    ValidHtmlFilter.class.getName() + "SKIP_FILTER";
040    
041            protected String getContent(HttpServletRequest request, String content) {
042                    content = StringUtil.replaceLast(
043                            content, _CLOSE_BODY, StringPool.BLANK);
044                    content = StringUtil.replaceLast(
045                            content, _CLOSE_HTML, _CLOSE_BODY + _CLOSE_HTML);
046    
047                    return content;
048            }
049    
050            protected boolean isAlreadyFiltered(HttpServletRequest request) {
051                    if (request.getAttribute(SKIP_FILTER) != null) {
052                            return true;
053                    }
054                    else {
055                            return false;
056                    }
057            }
058    
059            protected boolean isEnsureValidHtml(
060                    HttpServletRequest request, HttpServletResponse response) {
061    
062                    String contentType = response.getContentType();
063    
064                    if ((contentType != null) &&
065                            contentType.startsWith(ContentTypes.TEXT_HTML)) {
066    
067                            return true;
068                    }
069                    else {
070                            return false;
071                    }
072            }
073    
074            protected void processFilter(
075                            HttpServletRequest request, HttpServletResponse response,
076                            FilterChain filterChain)
077                    throws Exception {
078    
079                    if (isEnsureValidHtml(request, response) &&
080                            !isAlreadyFiltered(request)) {
081    
082                            request.setAttribute(SKIP_FILTER, Boolean.TRUE);
083    
084                            if (_log.isDebugEnabled()) {
085                                    String completeURL = HttpUtil.getCompleteURL(request);
086    
087                                    _log.debug("Ensuring valid HTML " + completeURL);
088                            }
089    
090                            StringServletResponse stringServerResponse =
091                                    new StringServletResponse(response);
092    
093                            processFilter(
094                                    ValidHtmlFilter.class, request, stringServerResponse,
095                                    filterChain);
096    
097                            String content = getContent(
098                                    request, stringServerResponse.getString());
099    
100                            ServletResponseUtil.write(response, content);
101                    }
102                    else {
103                            if (_log.isDebugEnabled()) {
104                                    String completeURL = HttpUtil.getCompleteURL(request);
105    
106                                    _log.debug("Not ensuring valid HTML " + completeURL);
107                            }
108    
109                            processFilter(
110                                    ValidHtmlFilter.class, request, response, filterChain);
111                    }
112            }
113    
114            private static final String _CLOSE_BODY = "</body>";
115    
116            private static final String _CLOSE_HTML = "</html>";
117    
118            private static Log _log = LogFactoryUtil.getLog(ValidHtmlFilter.class);
119    
120    }