Java by API/javax.servlet.http/HttpSession
Содержание
bindings.listener
<source lang="java">
import java.io.IOException; import java.io.PrintWriter; import java.util.Date; import javax.servlet.ServletContext; 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 javax.servlet.http.HttpSessionBindingEvent; import javax.servlet.http.HttpSessionBindingListener; public class SessionBindings extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/plain");
PrintWriter out = res.getWriter();
// Get the current session object, create one if necessary
HttpSession session = req.getSession();
// Add a CustomBindingListener
session.setAttribute("bindings.listener", new CustomBindingListener(getServletContext()));
out.println("This page intentionally left blank");
}
} class CustomBindingListener implements HttpSessionBindingListener {
ServletContext context;
public CustomBindingListener(ServletContext context) {
this.context = context;
}
public void valueBound(HttpSessionBindingEvent event) {
context.log("[" + new Date() + "] BOUND as " + event.getName() + " to "
+ event.getSession().getId());
}
public void valueUnbound(HttpSessionBindingEvent event) {
context.log("[" + new Date() + "] UNBOUND as " + event.getName() + " from "
+ event.getSession().getId());
}
}
</source>
HttpSession: getAttributeNames()
<source lang="java">
import java.io.IOException; import java.io.PrintWriter; import java.util.Date; import java.util.Enumeration; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class SessionSnoop extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
HttpSession session = req.getSession();
Integer count = (Integer) session.getAttribute("count");
if (count == null)
count = new Integer(1);
else
count = new Integer(count.intValue() + 1);
session.setAttribute("count", count);
out.println("<HTML><HEAD><TITLE>Session Count</TITLE></HEAD>");
out.println("<BODY>Session Count
"); out.println("You"ve visited this page " + count
+ ((count == 1) ? " time." : " times."));
out.println(""); out.println("
Here is your saved session data:
"); Enumeration e = session.getAttributeNames();
while (e.hasMoreElements()) {
String name = (String) e.nextElement();
out.println(name + ": " + session.getAttribute(name) + "
");
}
out.println("Here are some vital stats on your session:
"); out.println("Session id: " + session.getId() + " (keep it secret)
");
out.println("New session: " + session.isNew() + "
");
out.println("Timeout: " + session.getMaxInactiveInterval());
out.println("(" + session.getMaxInactiveInterval() / 60 + " minutes)
");
out.println("Creation time: " + session.getCreationTime());
out.println("(" + new Date(session.getCreationTime()) + ")
");
out.println("Last access time: " + session.getLastAccessedTime());
out.println("(" + new Date(session.getLastAccessedTime()) + ")
");
out.println("Requested session ID from cookie: " + req.isRequestedSessionIdFromCookie()
+ "
");
out.println("Requested session ID from URL: " + req.isRequestedSessionIdFromURL() + "
");
out.println("Requested session ID valid: " + req.isRequestedSessionIdValid() + "
");
out.println("Test URL Rewriting
"); out.println("Click ");
out.println("to test that session tracking works via URL");
out.println("rewriting even when cookies aren"t supported.");
out.println("</BODY></HTML>");
}
}
</source>
HttpSession: getAttribute(String key)
<source lang="java">
import java.io.IOException; import java.io.PrintWriter; import java.util.Date; import java.util.Enumeration; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class SessionSnoop extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
HttpSession session = req.getSession();
Integer count = (Integer) session.getAttribute("count");
if (count == null)
count = new Integer(1);
else
count = new Integer(count.intValue() + 1);
session.setAttribute("count", count);
out.println("<HTML><HEAD><TITLE>Session Count</TITLE></HEAD>");
out.println("<BODY>Session Count
"); out.println("You"ve visited this page " + count
+ ((count == 1) ? " time." : " times."));
out.println("<P>");
out.println("Here is your saved session data:
"); Enumeration e = session.getAttributeNames();
while (e.hasMoreElements()) {
String name = (String) e.nextElement();
out.println(name + ": " + session.getAttribute(name) + "
");
}
out.println("Here are some vital stats on your session:
"); out.println("Session id: " + session.getId() + " (keep it secret)
");
out.println("New session: " + session.isNew() + "
");
out.println("Timeout: " + session.getMaxInactiveInterval());
out.println("(" + session.getMaxInactiveInterval() / 60 + " minutes)
");
out.println("Creation time: " + session.getCreationTime());
out.println("(" + new Date(session.getCreationTime()) + ")
");
out.println("Last access time: " + session.getLastAccessedTime());
out.println("(" + new Date(session.getLastAccessedTime()) + ")
");
out.println("Requested session ID from cookie: " + req.isRequestedSessionIdFromCookie()
+ "
");
out.println("Requested session ID from URL: " + req.isRequestedSessionIdFromURL() + "
");
out.println("Requested session ID valid: " + req.isRequestedSessionIdValid() + "
");
out.println("Test URL Rewriting
"); out.println("Click ");
out.println("to test that session tracking works via URL");
out.println("rewriting even when cookies aren"t supported.");
out.println("</BODY></HTML>");
}
}
</source>
HttpSession: getCreationTime()
<source lang="java">
import java.io.IOException; import java.util.Date; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class ManualInvalidate extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
HttpSession session = req.getSession();
// Invalidate the session if it"s more than a day old or has been
// inactive for more than an hour.
if (!session.isNew()) { // skip new sessions
Date dayAgo = new Date(System.currentTimeMillis() - 24 * 60 * 60 * 1000);
Date hourAgo = new Date(System.currentTimeMillis() - 60 * 60 * 1000);
Date created = new Date(session.getCreationTime());
Date accessed = new Date(session.getLastAccessedTime());
if (created.before(dayAgo) || accessed.before(hourAgo)) {
session.invalidate();
session = req.getSession(); // get a new session
}
}
}
}
</source>
HttpSession: getId()
<source lang="java">
import java.io.IOException; import java.io.PrintWriter; import java.util.Date; import java.util.Enumeration; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class SessionSnoop extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
HttpSession session = req.getSession();
Integer count = (Integer) session.getAttribute("count");
if (count == null)
count = new Integer(1);
else
count = new Integer(count.intValue() + 1);
session.setAttribute("count", count);
out.println("<HTML><HEAD><TITLE>Session Count</TITLE></HEAD>");
out.println("<BODY>Session Count
"); out.println("You"ve visited this page " + count
+ ((count == 1) ? " time." : " times."));
out.println("<P>");
out.println("Here is your saved session data:
"); Enumeration e = session.getAttributeNames();
while (e.hasMoreElements()) {
String name = (String) e.nextElement();
out.println(name + ": " + session.getAttribute(name) + "
");
}
out.println("Here are some vital stats on your session:
"); out.println("Session id: " + session.getId() + " (keep it secret)
");
out.println("New session: " + session.isNew() + "
");
out.println("Timeout: " + session.getMaxInactiveInterval());
out.println("(" + session.getMaxInactiveInterval() / 60 + " minutes)
");
out.println("Creation time: " + session.getCreationTime());
out.println("(" + new Date(session.getCreationTime()) + ")
");
out.println("Last access time: " + session.getLastAccessedTime());
out.println("(" + new Date(session.getLastAccessedTime()) + ")
");
out.println("Requested session ID from cookie: " + req.isRequestedSessionIdFromCookie()
+ "
");
out.println("Requested session ID from URL: " + req.isRequestedSessionIdFromURL() + "
");
out.println("Requested session ID valid: " + req.isRequestedSessionIdValid() + "
");
out.println("Test URL Rewriting
"); out.println("Click ");
out.println("to test that session tracking works via URL");
out.println("rewriting even when cookies aren"t supported.");
out.println("</BODY></HTML>");
}
}
</source>
HttpSession: getLastAccessedTime()
<source lang="java">
import java.io.IOException; import java.util.Date; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class ManualInvalidate extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
HttpSession session = req.getSession();
// Invalidate the session if it"s more than a day old or has been
// inactive for more than an hour.
if (!session.isNew()) { // skip new sessions
Date dayAgo = new Date(System.currentTimeMillis() - 24 * 60 * 60 * 1000);
Date hourAgo = new Date(System.currentTimeMillis() - 60 * 60 * 1000);
Date created = new Date(session.getCreationTime());
Date accessed = new Date(session.getLastAccessedTime());
if (created.before(dayAgo) || accessed.before(hourAgo)) {
session.invalidate();
session = req.getSession(); // get a new session
}
}
}
}
</source>
HttpSession: getLastAccessedTime() (2)
<source lang="java">
import java.io.IOException; import java.io.PrintWriter; import java.util.Date; import java.util.Enumeration; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class SessionSnoop extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
HttpSession session = req.getSession();
Integer count = (Integer) session.getAttribute("count");
if (count == null)
count = new Integer(1);
else
count = new Integer(count.intValue() + 1);
session.setAttribute("count", count);
out.println("<HTML><HEAD><TITLE>Session Count</TITLE></HEAD>");
out.println("<BODY>Session Count
"); out.println("You"ve visited this page " + count
+ ((count == 1) ? " time." : " times."));
out.println("<P>");
out.println("Here is your saved session data:
"); Enumeration e = session.getAttributeNames();
while (e.hasMoreElements()) {
String name = (String) e.nextElement();
out.println(name + ": " + session.getAttribute(name) + "
");
}
out.println("Here are some vital stats on your session:
"); out.println("Session id: " + session.getId() + " (keep it secret)
");
out.println("New session: " + session.isNew() + "
");
out.println("Timeout: " + session.getMaxInactiveInterval());
out.println("(" + session.getMaxInactiveInterval() / 60 + " minutes)
");
out.println("Creation time: " + session.getCreationTime());
out.println("(" + new Date(session.getCreationTime()) + ")
");
out.println("Last access time: " + session.getLastAccessedTime());
out.println("(" + new Date(session.getLastAccessedTime()) + ")
");
out.println("Requested session ID from cookie: " + req.isRequestedSessionIdFromCookie()
+ "
");
out.println("Requested session ID from URL: " + req.isRequestedSessionIdFromURL() + "
");
out.println("Requested session ID valid: " + req.isRequestedSessionIdValid() + "
");
out.println("Test URL Rewriting
"); out.println("Click ");
out.println("to test that session tracking works via URL");
out.println("rewriting even when cookies aren"t supported.");
out.println("</BODY></HTML>");
}
}
</source>
HttpSession: getMaxInactiveInterval()
<source lang="java">
import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class SessionTimer extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
HttpSession session = req.getSession();
out.println("<HTML><HEAD><TITLE>SessionTimer</TITLE></HEAD>");
out.println("<BODY>Session Timer
"); out.println("The previous timeout was " + session.getMaxInactiveInterval());
out.println("
");
session.setMaxInactiveInterval(2 * 60 * 60); // two hours
out.println("The newly assigned timeout is " + session.getMaxInactiveInterval());
out.println("</BODY></HTML>");
}
}
</source>
HttpSession: invalidate()
<source lang="java">
import java.io.IOException; import java.util.Date; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class ManualInvalidate extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
HttpSession session = req.getSession();
// Invalidate the session if it"s more than a day old or has been
// inactive for more than an hour.
if (!session.isNew()) { // skip new sessions
Date dayAgo = new Date(System.currentTimeMillis() - 24 * 60 * 60 * 1000);
Date hourAgo = new Date(System.currentTimeMillis() - 60 * 60 * 1000);
Date created = new Date(session.getCreationTime());
Date accessed = new Date(session.getLastAccessedTime());
if (created.before(dayAgo) || accessed.before(hourAgo)) {
session.invalidate();
session = req.getSession(); // get a new session
}
}
}
}
</source>
HttpSession: isNew()
<source lang="java">
import java.io.IOException; import java.io.PrintWriter; import java.util.Date; import java.util.Enumeration; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class SessionSnoop extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
HttpSession session = req.getSession();
Integer count = (Integer) session.getAttribute("count");
if (count == null)
count = new Integer(1);
else
count = new Integer(count.intValue() + 1);
session.setAttribute("count", count);
out.println("<HTML><HEAD><TITLE>Session Count</TITLE></HEAD>");
out.println("<BODY>Session Count
"); out.println("You"ve visited this page " + count
+ ((count == 1) ? " time." : " times."));
out.println("<P>");
out.println("Here is your saved session data:
"); Enumeration e = session.getAttributeNames();
while (e.hasMoreElements()) {
String name = (String) e.nextElement();
out.println(name + ": " + session.getAttribute(name) + "
");
}
out.println("Here are some vital stats on your session:
"); out.println("Session id: " + session.getId() + " (keep it secret)
");
out.println("New session: " + session.isNew() + "
");
out.println("Timeout: " + session.getMaxInactiveInterval());
out.println("(" + session.getMaxInactiveInterval() / 60 + " minutes)
");
out.println("Creation time: " + session.getCreationTime());
out.println("(" + new Date(session.getCreationTime()) + ")
");
out.println("Last access time: " + session.getLastAccessedTime());
out.println("(" + new Date(session.getLastAccessedTime()) + ")
");
out.println("Requested session ID from cookie: " + req.isRequestedSessionIdFromCookie()
+ "
");
out.println("Requested session ID from URL: " + req.isRequestedSessionIdFromURL() + "
");
out.println("Requested session ID valid: " + req.isRequestedSessionIdValid() + "
");
out.println("Test URL Rewriting
"); out.println("Click ");
out.println("to test that session tracking works via URL");
out.println("rewriting even when cookies aren"t supported.");
out.println("</BODY></HTML>");
}
}
</source>
HttpSession: setAttribute(String key, Object value)
<source lang="java">
import java.io.IOException; import java.io.PrintWriter; import java.util.Date; import java.util.Enumeration; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class SessionSnoop extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
HttpSession session = req.getSession();
Integer count = (Integer) session.getAttribute("count");
if (count == null)
count = new Integer(1);
else
count = new Integer(count.intValue() + 1);
session.setAttribute("count", count);
out.println("<HTML><HEAD><TITLE>Session Count</TITLE></HEAD>");
out.println("<BODY>Session Count
"); out.println("You"ve visited this page " + count
+ ((count == 1) ? " time." : " times."));
out.println("<P>");
out.println("Here is your saved session data:
"); Enumeration e = session.getAttributeNames();
while (e.hasMoreElements()) {
String name = (String) e.nextElement();
out.println(name + ": " + session.getAttribute(name) + "
");
}
out.println("Here are some vital stats on your session:
"); out.println("Session id: " + session.getId() + " (keep it secret)
");
out.println("New session: " + session.isNew() + "
");
out.println("Timeout: " + session.getMaxInactiveInterval());
out.println("(" + session.getMaxInactiveInterval() / 60 + " minutes)
");
out.println("Creation time: " + session.getCreationTime());
out.println("(" + new Date(session.getCreationTime()) + ")
");
out.println("Last access time: " + session.getLastAccessedTime());
out.println("(" + new Date(session.getLastAccessedTime()) + ")
");
out.println("Requested session ID from cookie: " + req.isRequestedSessionIdFromCookie()
+ "
");
out.println("Requested session ID from URL: " + req.isRequestedSessionIdFromURL() + "
");
out.println("Requested session ID valid: " + req.isRequestedSessionIdValid() + "
");
out.println("Test URL Rewriting
"); out.println("Click ");
out.println("to test that session tracking works via URL");
out.println("rewriting even when cookies aren"t supported.");
out.println("</BODY></HTML>");
}
}
</source>
HttpSession: setMaxInactiveInterval(int arg0)
<source lang="java">
import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class SessionTimer extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
HttpSession session = req.getSession();
out.println("<HTML><HEAD><TITLE>SessionTimer</TITLE></HEAD>");
out.println("<BODY>Session Timer
"); out.println("The previous timeout was " + session.getMaxInactiveInterval());
out.println("
");
session.setMaxInactiveInterval(2 * 60 * 60); // two hours
out.println("The newly assigned timeout is " + session.getMaxInactiveInterval());
out.println("</BODY></HTML>");
}
}
</source>
