Java by API/javax.servlet.http/HttpSession

Материал из Java эксперт
Перейти к: навигация, поиск

bindings.listener

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());
  }
}





HttpSession: getAttributeNames()

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><H1>Session Count</H1>");
    out.println("You"ve visited this page " + count
        + ((count == 1) ? " time." : " times."));
    out.println("<P>");
    out.println("<H3>Here is your saved session data:</H3>");
    Enumeration e = session.getAttributeNames();
    while (e.hasMoreElements()) {
      String name = (String) e.nextElement();
      out.println(name + ": " + session.getAttribute(name) + "<BR>");
    }
    out.println("<H3>Here are some vital stats on your session:</H3>");
    out.println("Session id: " + session.getId() + " <I>(keep it secret)</I><BR>");
    out.println("New session: " + session.isNew() + "<BR>");
    out.println("Timeout: " + session.getMaxInactiveInterval());
    out.println("<I>(" + session.getMaxInactiveInterval() / 60 + " minutes)</I><BR>");
    out.println("Creation time: " + session.getCreationTime());
    out.println("<I>(" + new Date(session.getCreationTime()) + ")</I><BR>");
    out.println("Last access time: " + session.getLastAccessedTime());
    out.println("<I>(" + new Date(session.getLastAccessedTime()) + ")</I><BR>");
    out.println("Requested session ID from cookie: " + req.isRequestedSessionIdFromCookie()
        + "<BR>");
    out.println("Requested session ID from URL: " + req.isRequestedSessionIdFromURL() + "<BR>");
    out.println("Requested session ID valid: " + req.isRequestedSessionIdValid() + "<BR>");
    out.println("<H3>Test URL Rewriting</H3>");
    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>");
  }
}





HttpSession: getAttribute(String key)

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><H1>Session Count</H1>");
    out.println("You"ve visited this page " + count
        + ((count == 1) ? " time." : " times."));
    out.println("<P>");
    out.println("<H3>Here is your saved session data:</H3>");
    Enumeration e = session.getAttributeNames();
    while (e.hasMoreElements()) {
      String name = (String) e.nextElement();
      out.println(name + ": " + session.getAttribute(name) + "<BR>");
    }
    out.println("<H3>Here are some vital stats on your session:</H3>");
    out.println("Session id: " + session.getId() + " <I>(keep it secret)</I><BR>");
    out.println("New session: " + session.isNew() + "<BR>");
    out.println("Timeout: " + session.getMaxInactiveInterval());
    out.println("<I>(" + session.getMaxInactiveInterval() / 60 + " minutes)</I><BR>");
    out.println("Creation time: " + session.getCreationTime());
    out.println("<I>(" + new Date(session.getCreationTime()) + ")</I><BR>");
    out.println("Last access time: " + session.getLastAccessedTime());
    out.println("<I>(" + new Date(session.getLastAccessedTime()) + ")</I><BR>");
    out.println("Requested session ID from cookie: " + req.isRequestedSessionIdFromCookie()
        + "<BR>");
    out.println("Requested session ID from URL: " + req.isRequestedSessionIdFromURL() + "<BR>");
    out.println("Requested session ID valid: " + req.isRequestedSessionIdValid() + "<BR>");
    out.println("<H3>Test URL Rewriting</H3>");
    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>");
  }
}





HttpSession: getCreationTime()

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
      }
    }
  }
}





HttpSession: getId()

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><H1>Session Count</H1>");
    out.println("You"ve visited this page " + count
        + ((count == 1) ? " time." : " times."));
    out.println("<P>");
    out.println("<H3>Here is your saved session data:</H3>");
    Enumeration e = session.getAttributeNames();
    while (e.hasMoreElements()) {
      String name = (String) e.nextElement();
      out.println(name + ": " + session.getAttribute(name) + "<BR>");
    }
    out.println("<H3>Here are some vital stats on your session:</H3>");
    out.println("Session id: " + session.getId() + " <I>(keep it secret)</I><BR>");
    out.println("New session: " + session.isNew() + "<BR>");
    out.println("Timeout: " + session.getMaxInactiveInterval());
    out.println("<I>(" + session.getMaxInactiveInterval() / 60 + " minutes)</I><BR>");
    out.println("Creation time: " + session.getCreationTime());
    out.println("<I>(" + new Date(session.getCreationTime()) + ")</I><BR>");
    out.println("Last access time: " + session.getLastAccessedTime());
    out.println("<I>(" + new Date(session.getLastAccessedTime()) + ")</I><BR>");
    out.println("Requested session ID from cookie: " + req.isRequestedSessionIdFromCookie()
        + "<BR>");
    out.println("Requested session ID from URL: " + req.isRequestedSessionIdFromURL() + "<BR>");
    out.println("Requested session ID valid: " + req.isRequestedSessionIdValid() + "<BR>");
    out.println("<H3>Test URL Rewriting</H3>");
    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>");
  }
}





HttpSession: getLastAccessedTime()

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
      }
    }
  }
}





HttpSession: getLastAccessedTime() (2)

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><H1>Session Count</H1>");
    out.println("You"ve visited this page " + count
        + ((count == 1) ? " time." : " times."));
    out.println("<P>");
    out.println("<H3>Here is your saved session data:</H3>");
    Enumeration e = session.getAttributeNames();
    while (e.hasMoreElements()) {
      String name = (String) e.nextElement();
      out.println(name + ": " + session.getAttribute(name) + "<BR>");
    }
    out.println("<H3>Here are some vital stats on your session:</H3>");
    out.println("Session id: " + session.getId() + " <I>(keep it secret)</I><BR>");
    out.println("New session: " + session.isNew() + "<BR>");
    out.println("Timeout: " + session.getMaxInactiveInterval());
    out.println("<I>(" + session.getMaxInactiveInterval() / 60 + " minutes)</I><BR>");
    out.println("Creation time: " + session.getCreationTime());
    out.println("<I>(" + new Date(session.getCreationTime()) + ")</I><BR>");
    out.println("Last access time: " + session.getLastAccessedTime());
    out.println("<I>(" + new Date(session.getLastAccessedTime()) + ")</I><BR>");
    out.println("Requested session ID from cookie: " + req.isRequestedSessionIdFromCookie()
        + "<BR>");
    out.println("Requested session ID from URL: " + req.isRequestedSessionIdFromURL() + "<BR>");
    out.println("Requested session ID valid: " + req.isRequestedSessionIdValid() + "<BR>");
    out.println("<H3>Test URL Rewriting</H3>");
    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>");
  }
}





HttpSession: getMaxInactiveInterval()

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><H1>Session Timer</H1>");
    out.println("The previous timeout was " + session.getMaxInactiveInterval());
    out.println("<BR>");
    session.setMaxInactiveInterval(2 * 60 * 60); // two hours
    out.println("The newly assigned timeout is " + session.getMaxInactiveInterval());
    out.println("</BODY></HTML>");
  }
}





HttpSession: invalidate()

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
      }
    }
  }
}





HttpSession: isNew()

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><H1>Session Count</H1>");
    out.println("You"ve visited this page " + count
        + ((count == 1) ? " time." : " times."));
    out.println("<P>");
    out.println("<H3>Here is your saved session data:</H3>");
    Enumeration e = session.getAttributeNames();
    while (e.hasMoreElements()) {
      String name = (String) e.nextElement();
      out.println(name + ": " + session.getAttribute(name) + "<BR>");
    }
    out.println("<H3>Here are some vital stats on your session:</H3>");
    out.println("Session id: " + session.getId() + " <I>(keep it secret)</I><BR>");
    out.println("New session: " + session.isNew() + "<BR>");
    out.println("Timeout: " + session.getMaxInactiveInterval());
    out.println("<I>(" + session.getMaxInactiveInterval() / 60 + " minutes)</I><BR>");
    out.println("Creation time: " + session.getCreationTime());
    out.println("<I>(" + new Date(session.getCreationTime()) + ")</I><BR>");
    out.println("Last access time: " + session.getLastAccessedTime());
    out.println("<I>(" + new Date(session.getLastAccessedTime()) + ")</I><BR>");
    out.println("Requested session ID from cookie: " + req.isRequestedSessionIdFromCookie()
        + "<BR>");
    out.println("Requested session ID from URL: " + req.isRequestedSessionIdFromURL() + "<BR>");
    out.println("Requested session ID valid: " + req.isRequestedSessionIdValid() + "<BR>");
    out.println("<H3>Test URL Rewriting</H3>");
    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>");
  }
}





HttpSession: setAttribute(String key, Object value)

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><H1>Session Count</H1>");
    out.println("You"ve visited this page " + count
        + ((count == 1) ? " time." : " times."));
    out.println("<P>");
    out.println("<H3>Here is your saved session data:</H3>");
    Enumeration e = session.getAttributeNames();
    while (e.hasMoreElements()) {
      String name = (String) e.nextElement();
      out.println(name + ": " + session.getAttribute(name) + "<BR>");
    }
    out.println("<H3>Here are some vital stats on your session:</H3>");
    out.println("Session id: " + session.getId() + " <I>(keep it secret)</I><BR>");
    out.println("New session: " + session.isNew() + "<BR>");
    out.println("Timeout: " + session.getMaxInactiveInterval());
    out.println("<I>(" + session.getMaxInactiveInterval() / 60 + " minutes)</I><BR>");
    out.println("Creation time: " + session.getCreationTime());
    out.println("<I>(" + new Date(session.getCreationTime()) + ")</I><BR>");
    out.println("Last access time: " + session.getLastAccessedTime());
    out.println("<I>(" + new Date(session.getLastAccessedTime()) + ")</I><BR>");
    out.println("Requested session ID from cookie: " + req.isRequestedSessionIdFromCookie()
        + "<BR>");
    out.println("Requested session ID from URL: " + req.isRequestedSessionIdFromURL() + "<BR>");
    out.println("Requested session ID valid: " + req.isRequestedSessionIdValid() + "<BR>");
    out.println("<H3>Test URL Rewriting</H3>");
    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>");
  }
}





HttpSession: setMaxInactiveInterval(int arg0)

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><H1>Session Timer</H1>");
    out.println("The previous timeout was " + session.getMaxInactiveInterval());
    out.println("<BR>");
    session.setMaxInactiveInterval(2 * 60 * 60); // two hours
    out.println("The newly assigned timeout is " + session.getMaxInactiveInterval());
    out.println("</BODY></HTML>");
  }
}


Источник — «http://jexp.ru/index.php?title=Java_by_API/javax.servlet.http/HttpSession&oldid=1755»