standardmanager.java

业界著名的tomcat服务器的最新6.0的源代码。

/*
 * 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.
 */


package org.apache.catalina.session;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
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.security.AccessController;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.ArrayList;
import java.util.Iterator;
import javax.servlet.ServletContext;
import org.apache.catalina.Container;
import org.apache.catalina.Context;
import org.apache.catalina.Globals;
import org.apache.catalina.Lifecycle;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.LifecycleListener;
import org.apache.catalina.Loader;
import org.apache.catalina.Session;
import org.apache.catalina.util.CustomObjectInputStream;
import org.apache.catalina.util.LifecycleSupport;

import org.apache.catalina.security.SecurityUtil;
/**
 * 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
 * @author Jean-Francois Arcand
 * @version $Revision: 467222 $ $Date: 2006-10-24 05:17:11 +0200 (mar., 24 oct. 2006) $
 */

public class StandardManager
    extends ManagerBase
    implements Lifecycle, PropertyChangeListener {

    // ---------------------------------------------------- Security Classes
    private class PrivilegedDoLoad
        implements PrivilegedExceptionAction {

        PrivilegedDoLoad() {
        }

        public Object run() throws Exception{
           doLoad();
           return null;
        }
    }

    private class PrivilegedDoUnload
        implements PrivilegedExceptionAction {

        PrivilegedDoUnload() {
        }

        public Object run() throws Exception{
            doUnload();
            return null;
        }

    }


    // ----------------------------------------------------- Instance Variables


    /**
     * The descriptive information about this implementation.
     */
    protected static final String info = "StandardManager/1.0";


    /**
     * The lifecycle event support for this component.
     */
    protected LifecycleSupport lifecycle = new LifecycleSupport(this);


    /**
     * The maximum number of active Sessions allowed, or -1 for no limit.
     */
    protected int maxActiveSessions = -1;


    /**
     * The descriptive name of this Manager implementation (for logging).
     */
    protected static String name = "StandardManager";


    /**
     * 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.
     * If this pathname is relative, it will be resolved against the
     * temporary working directory provided by our context, available via
     * the <code>javax.servlet.context.tempdir</code> context attribute.
     */
    protected String pathname = "SESSIONS.ser";


    /**
     * Has this component been started yet?
     */
    protected boolean started = false;


    /**
     * Number of session creations that failed due to maxActiveSessions.
     */
    protected int rejectedSessions = 0;


    /**
     * Processing time during session expiration.
     */
    protected long processingTime = 0;


    // ------------------------------------------------------------- Properties


    /**
     * Set the Container with which this Manager has been associated.  If
     * it is a Context (the usual case), listen for changes to the session
     * timeout property.
     *
     * @param container The associated Container
     */
    public void setContainer(Container container) {

        // De-register from the old Container (if any)
        if ((this.container != null) && (this.container instanceof Context))
            ((Context) this.container).removePropertyChangeListener(this);

        // Default processing provided by our superclass
        super.setContainer(container);

        // Register with the new Container (if any)
        if ((this.container != null) && (this.container instanceof Context)) {
            setMaxInactiveInterval
                ( ((Context) this.container).getSessionTimeout()*60 );
            ((Context) this.container).addPropertyChangeListener(this);
        }

    }


    /**
     * Return descriptive information about this Manager implementation and
     * the corresponding version number, in the format
     * <code>&lt;description&gt;/&lt;version&gt;</code>.
     */
    public String getInfo() {

        return (info);

    }


    /**
     * Return the maximum number of active Sessions allowed, or -1 for
     * no limit.
     */
    public int getMaxActiveSessions() {

        return (this.maxActiveSessions);

    }


    /** Number of session creations that failed due to maxActiveSessions
     *
     * @return The count
     */
    public int getRejectedSessions() {
        return rejectedSessions;
    }


    public void setRejectedSessions(int rejectedSessions) {
        this.rejectedSessions = rejectedSessions;
    }


    /**
     * 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 descriptive short name of this Manager implementation.
     */
    public String getName() {

        return (name);

    }


    /**
     * 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(String sessionId) {

        if ((maxActiveSessions >= 0) &&
            (sessions.size() >= maxActiveSessions)) {
            rejectedSessions++;
            throw new IllegalStateException
                (sm.getString("standardManager.createSession.ise"));
        }

        return (super.createSession(sessionId));

    }


    /**
     * Load any currently active sessions that were previously unloaded
     * to the appropriate persistence mechanism, if any.  If persistence is not
     * supported, this method returns without doing anything.
     *
     * @exception ClassNotFoundException if a serialized class cannot be
     *  found during the reload
     * @exception IOException if an input/output error occurs
     */
    public void load() throws ClassNotFoundException, IOException {
        if (SecurityUtil.isPackageProtectionEnabled()){
            try{
                AccessController.doPrivileged( new PrivilegedDoLoad() );
            } catch (PrivilegedActionException ex){
                Exception exception = ex.getException();
                if (exception instanceof ClassNotFoundException){
                    throw (ClassNotFoundException)exception;
                } else if (exception instanceof IOException){
                    throw (IOException)exception;
                }
                if (log.isDebugEnabled())
                    log.debug("Unreported exception in load() "
                        + exception);
            }
        } else {
            doLoad();
        }
    }


    /**
     * Load any currently active sessions that were previously unloaded
     * to the appropriate persistence mechanism, if any.  If persistence is not
     * supported, this method returns without doing anything.
     *
     * @exception ClassNotFoundException if a serialized class cannot be
     *  found during the reload
     * @exception IOException if an input/output error occurs
     */
    protected void doLoad() throws ClassNotFoundException, IOException {
        if (log.isDebugEnabled())
            log.debug("Start: Loading persisted sessions");

        // Initialize our internal data structures
        sessions.clear();

        // Open an input stream to the specified pathname, if any
        File file = file();
        if (file == null)
            return;
        if (log.isDebugEnabled())
            log.debug(sm.getString("standardManager.loading", pathname));
        FileInputStream fis = null;
        ObjectInputStream ois = null;
        Loader loader = null;
        ClassLoader classLoader = null;
        try {
            fis = new FileInputStream(file.getAbsolutePath());
            BufferedInputStream bis = new BufferedInputStream(fis);
            if (container != null)
                loader = container.getLoader();
            if (loader != null)
                classLoader = loader.getClassLoader();
            if (classLoader != null) {
                if (log.isDebugEnabled())
                    log.debug("Creating custom object input stream for class loader ");
                ois = new CustomObjectInputStream(bis, classLoader);
            } else {
                if (log.isDebugEnabled())
                    log.debug("Creating standard object input stream");
                ois = new ObjectInputStream(bis);
            }
        } catch (FileNotFoundException e) {
            if (log.isDebugEnabled())
                log.debug("No persisted data file found");
            return;
        } catch (IOException e) {
            log.error(sm.getString("standardManager.loading.ioe", e), e);
            if (ois != null) {
                try {
                    ois.close();
                } catch (IOException f) {
                    ;