/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.io.IOException;
import java.io.PrintWriter;
import java.net.URLEncoder;
import java.util.Date;
import java.util.Enumeration;
import java.util.ResourceBundle;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import util.HTMLFilter;
/**
* Example servlet showing request headers
*/
public class SessionExample
extends HttpServlet
{
private static final long serialVersionUID = 1L
;
private static final int SESSION_ATTRIBUTE_COUNT_LIMIT =
10;
@
Override
public void doGet
(HttpServletRequest request, HttpServletResponse response
) throws IOException, ServletException
{
ResourceBundle rb =
ResourceBundle.
getBundle("LocalStrings", request.
getLocale());
response.
setContentType("text/html");
response.
setCharacterEncoding("UTF-8");
PrintWriter out = response.
getWriter();
out.
println("<!DOCTYPE html><html>");
out.
println("<head>");
out.
println("<meta charset=\"UTF-8\" />");
String title = rb.
getString("sessions.title");
out.
println("<title>" + title +
"</title>");
out.
println("</head>");
out.
println("<body bgcolor=\"white\">");
out.
println("<a href=\"../sessions.html\">");
out.
println(
"<img src=\"../images/code.gif\" height=24 " +
"width=24 align=right border=0 alt=\"view code\"></a>");
out.
println("<a href=\"../index.html\">");
out.
println(
"<img src=\"../images/return.gif\" height=24 " +
"width=24 align=right border=0 alt=\"return\"></a>");
out.
println("<h3>" + title +
"</h3>");
HttpSession session = request.
getSession(true);
out.
println(rb.
getString("sessions.id") +
" " + session.
getId());
out.
println("<br>");
out.
println(rb.
getString("sessions.created") +
" ");
out.
println(new Date(session.
getCreationTime()) +
"<br>");
out.
println(rb.
getString("sessions.lastaccessed") +
" ");
out.
println(new Date(session.
getLastAccessedTime()));
// Count the existing attributes
int sessionAttributeCount =
0;
Enumeration<String> names = session.
getAttributeNames();
while (names.
hasMoreElements()) {
names.
nextElement();
sessionAttributeCount++
;
}
String dataName = request.
getParameter("dataname");
String dataValue = request.
getParameter("datavalue");
if (dataName
!=
null) {
if (dataValue ==
null) {
session.
removeAttribute(dataName
);
sessionAttributeCount--
;
} else if (sessionAttributeCount
< SESSION_ATTRIBUTE_COUNT_LIMIT
) {
session.
setAttribute(dataName, dataValue
);
sessionAttributeCount++
;
} else {
out.
print("<p> Session attribute [");
out.
print(HTMLFilter.
filter(dataName
));
out.
print("] not added as there are already "+ SESSION_ATTRIBUTE_COUNT_LIMIT +
" attributes in the ");
out.
println("session. Delete an attribute before adding another.");
}
}
out.
println("<p>");
out.
println(rb.
getString("sessions.data") +
"<br>");
names = session.
getAttributeNames();
while (names.
hasMoreElements()) {
String name = names.
nextElement();
String value = session.
getAttribute(name
).
toString();
out.
println(HTMLFilter.
filter(name
) +
" = " + HTMLFilter.
filter(value
));
out.
print("<a href=\"");
out.
print(HTMLFilter.
filter(
response.
encodeURL("SessionExample?dataname=" +
URLEncoder.
encode(name,
"UTF-8"))));
out.
println("\" >delete</a>");
out.
println("<br>");
}
if (sessionAttributeCount
< SESSION_ATTRIBUTE_COUNT_LIMIT
) {
out.
println("<p>");
out.
print("<form action=\"");
out.
print(response.
encodeURL("SessionExample"));
out.
print("\" ");
out.
println("method=POST>");
out.
println(rb.
getString("sessions.dataname"));
out.
println("<input type=text size=20 name=dataname>");
out.
println("<br>");
out.
println(rb.
getString("sessions.datavalue"));
out.
println("<input type=text size=20 name=datavalue>");
out.
println("<br>");
out.
println("<input type=submit>");
out.
println("</form>");
out.
println("<p>GET based form:<br>");
out.
print("<form action=\"");
out.
print(response.
encodeURL("SessionExample"));
out.
print("\" ");
out.
println("method=GET>");
out.
println(rb.
getString("sessions.dataname"));
out.
println("<input type=text size=20 name=dataname>");
out.
println("<br>");
out.
println(rb.
getString("sessions.datavalue"));
out.
println("<input type=text size=20 name=datavalue>");
out.
println("<br>");
out.
println("<input type=submit>");
out.
println("</form>");
out.
print("<p><a href=\"");
out.
print(HTMLFilter.
filter(response.
encodeURL("SessionExample?dataname=exampleName&datavalue=exampleValue")));
out.
println("\" >URL encoded </a>");
} else {
out.
print("<p>You may not add more than " + SESSION_ATTRIBUTE_COUNT_LIMIT +
" attributes to this session.");
}
out.
println("</body>");
out.
println("</html>");
}
@
Override
public void doPost
(HttpServletRequest request, HttpServletResponse response
) throws IOException, ServletException
{
doGet
(request, response
);
}
}