001    /**
002     * Copyright (c) 2000-2012 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.FastDateFormatFactoryUtil;
019    import com.liferay.portal.kernel.util.GetterUtil;
020    import com.liferay.portal.kernel.util.HttpUtil;
021    import com.liferay.portal.kernel.util.SetUtil;
022    import com.liferay.portal.kernel.util.TimeZoneUtil;
023    import com.liferay.portal.kernel.util.Validator;
024    import com.liferay.portal.servlet.filters.BasePortalFilter;
025    import com.liferay.portal.util.PortalUtil;
026    import com.liferay.portal.util.PropsValues;
027    
028    import java.text.Format;
029    
030    import java.util.Calendar;
031    import java.util.Enumeration;
032    import java.util.GregorianCalendar;
033    import java.util.Locale;
034    import java.util.Map;
035    import java.util.Set;
036    
037    import javax.servlet.FilterChain;
038    import javax.servlet.FilterConfig;
039    import javax.servlet.http.HttpServletRequest;
040    import javax.servlet.http.HttpServletResponse;
041    import javax.servlet.http.HttpSession;
042    
043    /**
044     * @author Brian Wing Shun Chan
045     * @author Raymond Augé
046     * @author Eduardo Lundgren
047     */
048    public class HeaderFilter extends BasePortalFilter {
049    
050            @Override
051            public void init(FilterConfig filterConfig) {
052                    super.init(filterConfig);
053    
054                    _filterConfig = filterConfig;
055                    _dateFormat = FastDateFormatFactoryUtil.getSimpleDateFormat(
056                            _DATE_FORMAT, Locale.US, TimeZoneUtil.getTimeZone(_TIME_ZONE));
057            }
058    
059            protected long getLastModified(HttpServletRequest request) {
060                    long lasModified = -1;
061    
062                    Map<String, String[]> parameterMap = HttpUtil.getParameterMap(
063                            request.getQueryString());
064    
065                    String[] value = parameterMap.get("t");
066    
067                    if ((value != null) && (value.length > 0)) {
068                            lasModified = GetterUtil.getLong(value[0]);
069                    }
070    
071                    return lasModified;
072            }
073    
074            @Override
075            protected void processFilter(
076                            HttpServletRequest request, HttpServletResponse response,
077                            FilterChain filterChain)
078                    throws Exception {
079    
080                    Enumeration<String> enu = _filterConfig.getInitParameterNames();
081    
082                    while (enu.hasMoreElements()) {
083                            String name = enu.nextElement();
084    
085                            if (_requestHeaderIgnoreInitParams.contains(name)) {
086                                    continue;
087                            }
088    
089                            String value = _filterConfig.getInitParameter(name);
090    
091                            if (name.equals(_EXPIRES) && Validator.isNumber(value)) {
092                                    int seconds = GetterUtil.getInteger(value);
093    
094                                    Calendar cal = new GregorianCalendar();
095    
096                                    cal.add(Calendar.SECOND, seconds);
097    
098                                    value = _dateFormat.format(cal.getTime());
099                            }
100    
101                            // LEP-5895 and LPS-15802
102    
103                            boolean addHeader = true;
104    
105                            if (name.equalsIgnoreCase(HttpHeaders.CACHE_CONTROL) ||
106                                    name.equalsIgnoreCase(HttpHeaders.EXPIRES)) {
107    
108                                    boolean newSession = false;
109    
110                                    HttpSession session = request.getSession(false);
111    
112                                    if ((session == null) || session.isNew()) {
113                                            newSession = true;
114                                    }
115    
116                                    String contextPath = request.getContextPath();
117    
118                                    if (name.equalsIgnoreCase(HttpHeaders.EXPIRES) && newSession) {
119                                            addHeader = false;
120                                    }
121                                    else if (PropsValues.WEB_SERVER_PROXY_LEGACY_MODE &&
122                                                     newSession &&
123                                                     contextPath.equals(PortalUtil.getPathContext())) {
124    
125                                            addHeader = false;
126                                    }
127                            }
128    
129                            if (addHeader) {
130                                    response.addHeader(name, value);
131                            }
132                    }
133    
134                    long lastModified = getLastModified(request);
135                    long ifModifiedSince = request.getDateHeader(
136                            HttpHeaders.IF_MODIFIED_SINCE);
137    
138                    if (lastModified > 0) {
139                            response.setDateHeader(HttpHeaders.LAST_MODIFIED, lastModified);
140    
141                            if (lastModified <= ifModifiedSince) {
142                                    response.setDateHeader(
143                                            HttpHeaders.LAST_MODIFIED, ifModifiedSince);
144                                    response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
145    
146                                    return;
147                            }
148                    }
149    
150                    processFilter(HeaderFilter.class, request, response, filterChain);
151            }
152    
153            private static final String _DATE_FORMAT = "EEE, dd MMM yyyy HH:mm:ss z";
154    
155            private static final String _EXPIRES = "Expires";
156    
157            private static final String _TIME_ZONE = "GMT";
158    
159            private static Set<String> _requestHeaderIgnoreInitParams =
160                    SetUtil.fromArray(PropsValues.REQUEST_HEADER_IGNORE_INIT_PARAMS);
161    
162            private Format _dateFormat;
163            private FilterConfig _filterConfig;
164    
165    }