/*
* $Header: /home/cvs/jakarta-tomcat/proposals/catalina/src/share/org/apache/tomcat/session/StandardManager.java,v 1.4 2000/01/31 05:29:04 craigmcc Exp $
* $Revision: 1.4 $
* $Date: 2000/01/31 05:29:04 $
*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
* [Additional notices, if required by prior licensing conditions]
*
*/
package org.apache.tomcat.session;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpSession;
import org.apache.tomcat.Lifecycle;
import org.apache.tomcat.LifecycleException;
import org.apache.tomcat.Manager;
import org.apache.tomcat.Request;
import org.apache.tomcat.Session;
import org.apache.tomcat.util.StringManager;
/**
* Standard implementation of the <b>Manager</b> interface that provides
* simple session persistence across restarts of this component (such as
* when the entire server is shut down and restarted, or when a particular
* web application is reloaded.
* <p>
* <b>IMPLEMENTATION NOTE</b>: Correct behavior of session storing and
* reloading depends upon external calls to the <code>start()</code> and
* <code>stop()</code> methods of this class at the correct times.
*
* @author Craig R. McClanahan
* @version $Revision: 1.4 $ $Date: 2000/01/31 05:29:04 $
*/
public final class StandardManager
extends ManagerBase
implements Lifecycle, Runnable {
// ----------------------------------------------------- Instance Variables
/**
* The interval (in seconds) between checks for expired sessions.
*/
private int checkInterval = 60;
/**
* The descriptive information about this implementation.
*/
private static final String info = "StandardManager/1.0";
/**
* The maximum number of active Sessions allowed, or -1 for no limit.
*/
private int maxActiveSessions = -1;
/**
* Path name of the disk file in which active sessions are saved
* when we stop, and from which these sessions are loaded when we start.
* A <code>null</code> value indicates that no persistence is desired.
*/
private String pathname = null;
/**
* The string manager for this package.
*/
private StringManager sm =
StringManager.getManager(Constants.Package);
/**
* Has this component been started yet?
*/
private boolean started = false;
/**
* The background thread.
*/
private Thread thread = null;
/**
* The background thread completion semaphore.
*/
private boolean threadDone = false;
/**
* Name to register for the background thread.
*/
private String threadName = "StandardManager";
// ------------------------------------------------------------- Properties
/**
* Return the check interval (in seconds) for this Manager.
*/
public int getCheckInterval() {
return (this.checkInterval);
}
/**
* Set the check interval (in seconds) for this Manager.
*
* @param checkInterval The new check interval
*/
public void setCheckInterval(int checkInterval) {
int oldCheckInterval = this.checkInterval;
this.checkInterval = checkInterval;
support.firePropertyChange("checkInterval",
new Integer(oldCheckInterval),
new Integer(this.checkInterval));
}
/**
* Return descriptive information about this Manager implementation and
* the corresponding version number, in the format
* <code><description>/<version></code>.
*/
public String getInfo() {
return (this.info);
}
/**
* Return the maximum number of active Sessions allowed, or -1 for
* no limit.
*/
public int getMaxActiveSessions() {
return (this.maxActiveSessions);
}
/**
* Set the maximum number of actives Sessions allowed, or -1 for
* no limit.
*
* @param max The new maximum number of sessions
*/
public void setMaxActiveSessions(int max) {
int oldMaxActiveSessions = this.maxActiveSessions;
this.maxActiveSessions = max;
support.firePropertyChange("maxActiveSessions",
new Integer(oldMaxActiveSessions),
new Integer(this.maxActiveSessions));
}
/**
* Return the session persistence pathname, if any.
*/
public String getPathname() {
return (this.pathname);
}
/**
* Set the session persistence pathname to the specified value. If no
* persistence support is desired, set the pathname to <code>null</code>.
*
* @param pathname New session persistence pathname
*/
public void setPathname(String pathname) {
String oldPathname = this.pathname;
this.pathname = pathname;
support.firePropertyChange("pathname", oldPathname, this.pathname);
}
// --------------------------------------------------------- Public Methods
/**
* Construct and return a new session object, based on the default
* settings specified by this Manager's properties. The session
* id will be assigned by this method, and available via the getId()
* method of the returned session. If a new session cannot be created
* for any reason, return <code>null</code>.
*
* @exception IllegalStateException if a new session cannot be
* instantiated for any reason
*/
public Session createSession() {
if ((maxActiveSessions >= 0) &&
(sessions.size() >= maxActiveSessions))
throw new IllegalStateException
(sm.getString("standardManager.createSession.ise"));
return (super.createSession());
}
// ------------------------------------------------------ Lifecycle Methods
/**
* Prepare for the beginning of active use of the public methods of this
* component. This method should be called after <code>configure()</code>,
* and before any of the public methods of the component are utilized.
*
* @exception IllegalStateException if this component has already been
* started
* @exception LifecycleException if this component detects a fatal error
* that prevents this component from being used
*/
public void start() throws LifecycleException {
// Validate and update our current component state
if (started)
throw new LifecycleException
(sm.getString("standardManager.alreadyStarted"));
started = true;
// Load any previously persisted sessions
load();
// Start the background reaper thread
threadStart();
}
/**
* Gracefully terminate the active use of the public methods of this
* component. This method should be the last one called on a given
* instance of this component.
*
* @exception IllegalStateException if this component has not been started
* @exception LifecycleException if this component detects a fatal error
* that needs to be reported
*/
public void stop() throws LifecycleException {
// Validate and update our current component state
if (!started)
throw new LifecycleException
(sm.getString("standardManager.notStarted"));
started = false;
// Stop the background reaper thread
threadStop();
// Save any currently active sessions
unload();
// Expire all active sessions
Session sessions[] = findSessions();
for (int i = 0; i < sessions.length; i++) {
StandardSession session = (StandardSession) sessions[i];
if (!session.isValid())
continue;
session.expire();
}
}
// -------------------------------------------------------- Private Methods
/**
* Load any currently active sessions that were previously unloaded
* to the specified persistence file, if any.
*
* @exception LifecycleException if a fatal error is encountered
*/
private void load() throws LifecycleException {
// Initialize our internal data structures
recycled.removeAllElements();
sessions.clear();
// Open an input stream to the specified pathname, if any
if (pathname == null)
return;
FileInputStream fis = null;
ObjectInputStream ois = null;
try {
fis = new FileInputStream(pathname);
ois = new ObjectInputStream(new BufferedInputStream(fis));
} catch (FileNotFoundException e) {
return;
} catch (IOException e) {
if (ois != null) {
try {
ois.close();
} catch (IOException f) {
;
}
ois = null;
}
throw new LifecycleException("load/open: IOException", e);
}
// Load the previously unloaded active sessions
synchronized (sessions) {
try {
Integer count = (Integer) ois.readObject();
int n = count.intValue();
for (int i = 0; i < n; i++) {
Session session = (Session) ois.readObject();
sessions.put(session.getId(), session);
}
} catch (ClassNotFoundException e) {
if (ois != null) {
try {
ois.close();
} catch (IOException f) {
;
}
ois = null;
}
throw new LifecycleException
("load/read: ClassNotFoundException", e);
} catch (IOException e) {
if (ois != null) {
try {
ois.close();
} catch (IOException f) {
;
}
ois = null;
}
throw new LifecycleException("load/read: IOException", e);
}
}
// Close the input stream
try {
ois.close();
} catch (IOException f) {
;
}
}
/**
* Invalidate all sessions that have expired.
*/
private void processExpires() {
long timeNow = System.currentTimeMillis();
Session sessions[] = findSessions();
for (int i = 0; i < sessions.length; i++) {
StandardSession session = (StandardSession) sessions[i];
if (!session.isValid())
continue;
int maxInactiveInterval = session.getMaxInactiveInterval();
if (maxInactiveInterval < 0)
continue;
int timeIdle = // Truncate, do not round up
(int) ((timeNow - session.getLastAccessedTime()) / 1000L);
if (timeIdle >= maxInactiveInterval)
session.expire();
}
}
/**
* Save any currently active sessions in the specified persistence file,
* if any.
*
* @exception LifecycleException if a fatal error is encountered
*/
private void unload() throws LifecycleException {
// Open an output stream to the specified pathname, if any
if (pathname == null)
return;
FileOutputStream fos = null;
ObjectOutputStream oos = null;
try {
fos = new FileOutputStream(pathname);
oos = new ObjectOutputStream(new BufferedOutputStream(fos));
} catch (IOException e) {
if (oos != null) {
try {
oos.close();
} catch (IOException f) {
;
}
oos = null;
}
throw new LifecycleException("unload/open: IOException", e);
}
// Write the number of active sessions, followed by the details
synchronized (sessions) {
try {
oos.writeObject(new Integer(sessions.size()));
Enumeration elements = sessions.elements();
while (elements.hasMoreElements()) {
Session session = (Session) elements.nextElement();
oos.writeObject(session);
}
} catch (IOException e) {
if (oos != null) {
try {
oos.close();
} catch (IOException f) {
;
}
oos = null;
}
throw new LifecycleException("unload/write: IOException", e);
}
}
// Flush and close the output stream
try {
oos.flush();
oos.close();
oos = null;
} catch (IOException e) {
if (oos != null) {
try {
oos.close();
} catch (IOException f) {
;
}
oos = null;
}
throw new LifecycleException("unload/close: IOException", e);
}
}
/**
* Sleep for the duration specified by the <code>checkInterval</code>
* property.
*/
private void threadSleep() {
try {
Thread.sleep(checkInterval * 1000L);
} catch (InterruptedException e) {
;
}
}
/**
* Start the background thread that will periodically check for
* session timeouts.
*/
private void threadStart() {
if (thread != null)
return;
threadDone = false;
thread = new Thread(this, threadName);
thread.setDaemon(true);
thread.start();
}
/**
* Stop the background thread that is periodically checking for
* session timeouts.
*/
private void threadStop() {
if (thread == null)
return;
threadDone = true;
thread.interrupt();
try {
thread.join();
} catch (InterruptedException e) {
;
}
thread = null;
}
// ------------------------------------------------------ Background Thread
/**
* The background thread that checks for session timeouts and shutdown.
*/
public void run() {
// Loop until the termination semaphore is set
while (!threadDone) {
threadSleep();
processExpires();
}
}
}