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.StringUtil;
025    import com.liferay.portal.kernel.util.TimeZoneUtil;
026    import com.liferay.portal.kernel.util.Validator;
027    import com.liferay.portal.servlet.filters.BasePortalFilter;
028    import com.liferay.portal.util.PortalUtil;
029    import com.liferay.portal.util.PropsValues;
030    
031    import java.text.Format;
032    
033    import java.util.Calendar;
034    import java.util.Enumeration;
035    import java.util.GregorianCalendar;
036    import java.util.Map;
037    import java.util.Set;
038    
039    import javax.servlet.FilterChain;
040    import javax.servlet.FilterConfig;
041    import javax.servlet.http.HttpServletRequest;
042    import javax.servlet.http.HttpServletResponse;
043    import javax.servlet.http.HttpSession;
044    
045    /**
046     * @author Brian Wing Shun Chan
047     * @author Raymond Aug??
048     * @author Eduardo Lundgren
049     */
050    public class HeaderFilter extends BasePortalFilter {
051    
052            @Override
053            public void init(FilterConfig filterConfig) {
054                    super.init(filterConfig);
055    
056                    _filterConfig = filterConfig;
057                    _dateFormat = FastDateFormatFactoryUtil.getSimpleDateFormat(
058                            _DATE_FORMAT, LocaleUtil.US, TimeZoneUtil.GMT);
059            }
060    
061            protected long getLastModified(HttpServletRequest request) {
062                    long lasModified = -1;
063    
064                    Map<String, String[]> parameterMap = HttpUtil.getParameterMap(
065                            request.getQueryString());
066    
067                    String[] value = parameterMap.get("t");
068    
069                    if (ArrayUtil.isNotEmpty(value)) {
070                            lasModified = GetterUtil.getLong(value[0]);
071                    }
072    
073                    return lasModified;
074            }
075    
076            @Override
077            protected void processFilter(
078                            HttpServletRequest request, HttpServletResponse response,
079                            FilterChain filterChain)
080                    throws Exception {
081    
082                    Enumeration<String> enu = _filterConfig.getInitParameterNames();
083    
084                    while (enu.hasMoreElements()) {
085                            String name = enu.nextElement();
086    
087                            if (_requestHeaderIgnoreInitParams.contains(name)) {
088                                    continue;
089                            }
090    
091                            String value = _filterConfig.getInitParameter(name);
092    
093                            if (name.equals(_EXPIRES) && Validator.isNumber(value)) {
094                                    int seconds = GetterUtil.getInteger(value);
095    
096                                    Calendar cal = new GregorianCalendar();
097    
098                                    cal.add(Calendar.SECOND, seconds);
099    
100                                    value = _dateFormat.format(cal.getTime());
101                            }
102    
103                            // LEP-5895 and LPS-15802
104    
105                            boolean addHeader = true;
106    
107                            if (StringUtil.equalsIgnoreCase(name, HttpHeaders.CACHE_CONTROL) ||
108                                    StringUtil.equalsIgnoreCase(name, HttpHeaders.EXPIRES)) {
109    
110                                    boolean newSession = false;
111    
112                                    HttpSession session = request.getSession(false);
113    
114                                    if ((session == null) || session.isNew()) {
115                                            newSession = true;
116                                    }
117    
118                                    String contextPath = request.getContextPath();
119    
120                                    if (StringUtil.equalsIgnoreCase(name, HttpHeaders.EXPIRES) &&
121                                            newSession) {
122    
123                                            addHeader = false;
124                                    }
125                                    else if (PropsValues.WEB_SERVER_PROXY_LEGACY_MODE &&
126                                                     newSession &&
127                                                     contextPath.equals(PortalUtil.getPathContext())) {
128    
129                                            addHeader = false;
130                                    }
131                            }
132    
133                            if (addHeader) {
134                                    response.addHeader(name, value);
135                            }
136                    }
137    
138                    long lastModified = getLastModified(request);
139                    long ifModifiedSince = request.getDateHeader(
140                            HttpHeaders.IF_MODIFIED_SINCE);
141    
142                    if (lastModified > 0) {
143                            response.setDateHeader(HttpHeaders.LAST_MODIFIED, lastModified);
144    
145                            if (lastModified <= ifModifiedSince) {
146                                    response.setDateHeader(
147                                            HttpHeaders.LAST_MODIFIED, ifModifiedSince);
148                                    response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
149    
150                                    return;
151                            }
152                    }
153    
154                    processFilter(HeaderFilter.class, request, response, filterChain);
155            }
156    
157            private static final String _DATE_FORMAT = "EEE, dd MMM yyyy HH:mm:ss z";
158    
159            private static final String _EXPIRES = "Expires";
160    
161            private static Set<String> _requestHeaderIgnoreInitParams =
162                    SetUtil.fromArray(PropsValues.REQUEST_HEADER_IGNORE_INIT_PARAMS);
163    
164            private Format _dateFormat;
165            private FilterConfig _filterConfig;
166    
167    }