001    /**
002     * Copyright (c) 2000-2013 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.header;
016    
017    import com.liferay.portal.kernel.servlet.HttpHeaders;
018    import com.liferay.portal.kernel.util.ArrayUtil;
019    import com.liferay.portal.kernel.util.FastDateFormatFactoryUtil;
020    import com.liferay.portal.kernel.util.GetterUtil;
021    import com.liferay.portal.kernel.util.HttpUtil;
022    import com.liferay.portal.kernel.util.LocaleUtil;
023    import com.liferay.portal.kernel.util.SetUtil;
024    import com.liferay.portal.kernel.util.TimeZoneUtil;
025    import com.liferay.portal.kernel.util.Validator;
026    import com.liferay.portal.servlet.filters.BasePortalFilter;
027    import com.liferay.portal.util.PortalUtil;
028    import com.liferay.portal.util.PropsValues;
029    
030    import java.text.Format;
031    
032    import java.util.Calendar;
033    import java.util.Enumeration;
034    import java.util.GregorianCalendar;
035    import java.util.Map;
036    import java.util.Set;
037    
038    import javax.servlet.FilterChain;
039    import javax.servlet.FilterConfig;
040    import javax.servlet.http.HttpServletRequest;
041    import javax.servlet.http.HttpServletResponse;
042    import javax.servlet.http.HttpSession;
043    
044    /**
045     * @author Brian Wing Shun Chan
046     * @author Raymond Aug??
047     * @author Eduardo Lundgren
048     */
049    public class HeaderFilter extends BasePortalFilter {
050    
051            @Override
052            public void init(FilterConfig filterConfig) {
053                    super.init(filterConfig);
054    
055                    _filterConfig = filterConfig;
056                    _dateFormat = FastDateFormatFactoryUtil.getSimpleDateFormat(
057                            _DATE_FORMAT, LocaleUtil.US, TimeZoneUtil.GMT);
058            }
059    
060            protected long getLastModified(HttpServletRequest request) {
061                    long lasModified = -1;
062    
063                    Map<String, String[]> parameterMap = HttpUtil.getParameterMap(
064                            request.getQueryString());
065    
066                    String[] value = parameterMap.get("t");
067    
068                    if (ArrayUtil.isNotEmpty(value)) {
069                            lasModified = GetterUtil.getLong(value[0]);
070                    }
071    
072                    return lasModified;
073            }
074    
075            @Override
076            protected void processFilter(
077                            HttpServletRequest request, HttpServletResponse response,
078                            FilterChain filterChain)
079                    throws Exception {
080    
081                    Enumeration<String> enu = _filterConfig.getInitParameterNames();
082    
083                    while (enu.hasMoreElements()) {
084                            String name = enu.nextElement();
085    
086                            if (_requestHeaderIgnoreInitParams.contains(name)) {
087                                    continue;
088                            }
089    
090                            String value = _filterConfig.getInitParameter(name);
091    
092                            if (name.equals(_EXPIRES) && Validator.isNumber(value)) {
093                                    int seconds = GetterUtil.getInteger(value);
094    
095                                    Calendar cal = new GregorianCalendar();
096    
097                                    cal.add(Calendar.SECOND, seconds);
098    
099                                    value = _dateFormat.format(cal.getTime());
100                            }
101    
102                            // LEP-5895 and LPS-15802
103    
104                            boolean addHeader = true;
105    
106                            if (name.equalsIgnoreCase(HttpHeaders.CACHE_CONTROL) ||
107                                    name.equalsIgnoreCase(HttpHeaders.EXPIRES)) {
108    
109                                    boolean newSession = false;
110    
111                                    HttpSession session = request.getSession(false);
112    
113                                    if ((session == null) || session.isNew()) {
114                                            newSession = true;
115                                    }
116    
117                                    String contextPath = request.getContextPath();
118    
119                                    if (name.equalsIgnoreCase(HttpHeaders.EXPIRES) && newSession) {
120                                            addHeader = false;
121                                    }
122                                    else if (PropsValues.WEB_SERVER_PROXY_LEGACY_MODE &&
123                                                     newSession &&
124                                                     contextPath.equals(PortalUtil.getPathContext())) {
125    
126                                            addHeader = false;
127                                    }
128                            }
129    
130                            if (addHeader) {
131                                    response.addHeader(name, value);
132                            }
133                    }
134    
135                    long lastModified = getLastModified(request);
136                    long ifModifiedSince = request.getDateHeader(
137                            HttpHeaders.IF_MODIFIED_SINCE);
138    
139                    if (lastModified > 0) {
140                            response.setDateHeader(HttpHeaders.LAST_MODIFIED, lastModified);
141    
142                            if (lastModified <= ifModifiedSince) {
143                                    response.setDateHeader(
144                                            HttpHeaders.LAST_MODIFIED, ifModifiedSince);
145                                    response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
146    
147                                    return;
148                            }
149                    }
150    
151                    processFilter(HeaderFilter.class, request, response, filterChain);
152            }
153    
154            private static final String _DATE_FORMAT = "EEE, dd MMM yyyy HH:mm:ss z";
155    
156            private static final String _EXPIRES = "Expires";
157    
158            private static Set<String> _requestHeaderIgnoreInitParams =
159                    SetUtil.fromArray(PropsValues.REQUEST_HEADER_IGNORE_INIT_PARAMS);
160    
161            private Format _dateFormat;
162            private FilterConfig _filterConfig;
163    
164    }