1
19
20 package com.liferay.portal.servlet.filters.header;
21
22 import com.liferay.portal.kernel.servlet.HttpHeaders;
23 import com.liferay.portal.kernel.util.GetterUtil;
24 import com.liferay.portal.kernel.util.HttpUtil;
25 import com.liferay.portal.kernel.util.StringPool;
26 import com.liferay.portal.kernel.util.Validator;
27 import com.liferay.portal.servlet.filters.BasePortalFilter;
28
29 import java.io.IOException;
30
31 import java.text.DateFormat;
32 import java.text.SimpleDateFormat;
33
34 import java.util.Calendar;
35 import java.util.Enumeration;
36 import java.util.GregorianCalendar;
37 import java.util.Locale;
38 import java.util.Map;
39 import java.util.TimeZone;
40
41 import javax.servlet.FilterChain;
42 import javax.servlet.FilterConfig;
43 import javax.servlet.ServletException;
44 import javax.servlet.http.HttpServletRequest;
45 import javax.servlet.http.HttpServletResponse;
46 import javax.servlet.http.HttpSession;
47
48
56 public class HeaderFilter extends BasePortalFilter {
57
58 public void init(FilterConfig filterConfig) throws ServletException {
59 super.init(filterConfig);
60
61 _filterConfig = filterConfig;
62 _timeZone = TimeZone.getTimeZone(_TIME_ZONE);
63 }
64
65 protected long getLastModified(HttpServletRequest request) {
66 long lasModified = -1;
67
68 Map<String, String[]> parameterMap = HttpUtil.getParameterMap(
69 request.getQueryString());
70
71 String[] value = parameterMap.get("t");
72
73 if ((value != null) && (value.length > 0)) {
74 lasModified = GetterUtil.getLong(value[0]);
75 }
76
77 return lasModified;
78 }
79
80 protected void processFilter(
81 HttpServletRequest request, HttpServletResponse response,
82 FilterChain filterChain)
83 throws IOException, ServletException {
84
85 Enumeration<String> enu = _filterConfig.getInitParameterNames();
86
87 while (enu.hasMoreElements()) {
88 String name = enu.nextElement();
89
90 String value = _filterConfig.getInitParameter(name);
91
92 if (name.equals(_EXPIRES) && Validator.isNumber(value)) {
93 int seconds = GetterUtil.getInteger(value);
94
95 Calendar cal = new GregorianCalendar();
96
97 cal.add(Calendar.SECOND, seconds);
98
99 DateFormat dateFormat = new SimpleDateFormat(
100 _DATE_FORMAT, Locale.US);
101
102 dateFormat.setTimeZone(_timeZone);
103
104 value = dateFormat.format(cal.getTime());
105 }
106
107
109 boolean addHeader = true;
110
111 if (name.equalsIgnoreCase(HttpHeaders.CACHE_CONTROL)) {
112 HttpSession session = request.getSession(false);
113
114 if ((session == null) || session.isNew()) {
115 addHeader = false;
116 }
117 }
118
119 if (addHeader) {
120 response.addHeader(name, value);
121 }
122 }
123
124 long lastModified = getLastModified(request);
125 long ifModifiedSince = request.getDateHeader(
126 HttpHeaders.IF_MODIFIED_SINCE);
127
128 if (lastModified > 0) {
129 response.setDateHeader(HttpHeaders.LAST_MODIFIED, lastModified);
130
131 if (lastModified <= ifModifiedSince) {
132 response.setDateHeader(
133 HttpHeaders.LAST_MODIFIED, ifModifiedSince);
134 response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
135
136 return;
137 }
138 }
139
140 processFilter(HeaderFilter.class, request, response, filterChain);
141 }
142
143 private static final String _DATE_FORMAT = "EEE, dd MMM yyyy HH:mm:ss z";
144
145 private static final String _EXPIRES = "Expires";
146
147 private static final String _TIME_ZONE = StringPool.UTC;
148
149 private FilterConfig _filterConfig;
150 private TimeZone _timeZone;
151
152 }