containerbase.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.core;


import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.io.IOException;
import java.io.Serializable;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Iterator;

import javax.management.MBeanRegistration;
import javax.management.MBeanServer;
import javax.management.MalformedObjectNameException;
import javax.management.ObjectName;
import javax.naming.directory.DirContext;
import javax.servlet.ServletException;

import org.apache.catalina.Cluster;
import org.apache.catalina.Container;
import org.apache.catalina.ContainerEvent;
import org.apache.catalina.ContainerListener;
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.Manager;
import org.apache.catalina.Pipeline;
import org.apache.catalina.Realm;
import org.apache.catalina.Valve;
import org.apache.catalina.connector.Request;
import org.apache.catalina.connector.Response;
import org.apache.catalina.util.LifecycleSupport;
import org.apache.catalina.util.StringManager;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.naming.resources.ProxyDirContext;
import org.apache.tomcat.util.modeler.Registry;


/**
 * Abstract implementation of the <b>Container</b> interface, providing common
 * functionality required by nearly every implementation.  Classes extending
 * this base class must implement <code>getInfo()</code>, and may implement
 * a replacement for <code>invoke()</code>.
 * <p>
 * All subclasses of this abstract base class will include support for a
 * Pipeline object that defines the processing to be performed for each request
 * received by the <code>invoke()</code> method of this class, utilizing the
 * "Chain of Responsibility" design pattern.  A subclass should encapsulate its
 * own processing functionality as a <code>Valve</code>, and configure this
 * Valve into the pipeline by calling <code>setBasic()</code>.
 * <p>
 * This implementation fires property change events, per the JavaBeans design
 * pattern, for changes in singleton properties.  In addition, it fires the
 * following <code>ContainerEvent</code> events to listeners who register
 * themselves with <code>addContainerListener()</code>:
 * <table border=1>
 *   <tr>
 *     <th>Type</th>
 *     <th>Data</th>
 *     <th>Description</th>
 *   </tr>
 *   <tr>
 *     <td align=center><code>addChild</code></td>
 *     <td align=center><code>Container</code></td>
 *     <td>Child container added to this Container.</td>
 *   </tr>
 *   <tr>
 *     <td align=center><code>addValve</code></td>
 *     <td align=center><code>Valve</code></td>
 *     <td>Valve added to this Container.</td>
 *   </tr>
 *   <tr>
 *     <td align=center><code>removeChild</code></td>
 *     <td align=center><code>Container</code></td>
 *     <td>Child container removed from this Container.</td>
 *   </tr>
 *   <tr>
 *     <td align=center><code>removeValve</code></td>
 *     <td align=center><code>Valve</code></td>
 *     <td>Valve removed from this Container.</td>
 *   </tr>
 *   <tr>
 *     <td align=center><code>start</code></td>
 *     <td align=center><code>null</code></td>
 *     <td>Container was started.</td>
 *   </tr>
 *   <tr>
 *     <td align=center><code>stop</code></td>
 *     <td align=center><code>null</code></td>
 *     <td>Container was stopped.</td>
 *   </tr>
 * </table>
 * Subclasses that fire additional events should document them in the
 * class comments of the implementation class.
 *
 * @author Craig R. McClanahan
 */

public abstract class ContainerBase
    implements Container, Lifecycle, Pipeline, MBeanRegistration, Serializable {

    private static org.apache.juli.logging.Log log=
        org.apache.juli.logging.LogFactory.getLog( ContainerBase.class );

    /**
     * Perform addChild with the permissions of this class.
     * addChild can be called with the XML parser on the stack,
     * this allows the XML parser to have fewer privileges than
     * Tomcat.
     */
    protected class PrivilegedAddChild
        implements PrivilegedAction {

        private Container child;

        PrivilegedAddChild(Container child) {
            this.child = child;
        }

        public Object run() {
            addChildInternal(child);
            return null;
        }

    }


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


    /**
     * The child Containers belonging to this Container, keyed by name.
     */
    protected HashMap children = new HashMap();


    /**
     * The processor delay for this component.
     */
    protected int backgroundProcessorDelay = -1;


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


    /**
     * The container event listeners for this Container.
     */
    protected ArrayList listeners = new ArrayList();


    /**
     * The Loader implementation with which this Container is associated.
     */
    protected Loader loader = null;


    /**
     * The Logger implementation with which this Container is associated.
     */
    protected Log logger = null;


    /**
     * Associated logger name.
     */
    protected String logName = null;
    

    /**
     * The Manager implementation with which this Container is associated.
     */
    protected Manager manager = null;


    /**
     * The cluster with which this Container is associated.
     */
    protected Cluster cluster = null;

    
    /**
     * The human-readable name of this Container.
     */
    protected String name = null;


    /**
     * The parent Container to which this Container is a child.
     */
    protected Container parent = null;


    /**
     * The parent class loader to be configured when we install a Loader.
     */
    protected ClassLoader parentClassLoader = null;


    /**
     * The Pipeline object with which this Container is associated.
     */
    protected Pipeline pipeline = new StandardPipeline(this);


    /**
     * The Realm with which this Container is associated.
     */
    protected Realm realm = null;


    /**
     * The resources DirContext object with which this Container is associated.
     */
    protected DirContext resources = null;


    /**
     * The string manager for this package.
     */
    protected static StringManager sm =
        StringManager.getManager(Constants.Package);


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

    protected boolean initialized=false;

    /**
     * The property change support for this component.
     */
    protected PropertyChangeSupport support = new PropertyChangeSupport(this);


    /**
     * The background thread.
     */
    private Thread thread = null;


    /**
     * The background thread completion semaphore.
     */
    private boolean threadDone = false;


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


    /**
     * Get the delay between the invocation of the backgroundProcess method on
     * this container and its children. Child containers will not be invoked
     * if their delay value is not negative (which would mean they are using 
     * their own thread). Setting this to a positive value will cause 
     * a thread to be spawn. After waiting the specified amount of time, 
     * the thread will invoke the executePeriodic method on this container 
     * and all its children.
     */
    public int getBackgroundProcessorDelay() {
        return backgroundProcessorDelay;
    }


    /**
     * Set the delay between the invocation of the execute method on this
     * container and its children.
     * 
     * @param delay The delay in seconds between the invocation of 
     *              backgroundProcess methods
     */
    public void setBackgroundProcessorDelay(int delay) {
        backgroundProcessorDelay = delay;
    }


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


    /**
     * Return the Loader with which this Container is associated.  If there is
     * no associated Loader, return the Loader associated with our parent
     * Container (if any); otherwise, return <code>null</code>.
     */
    public Loader getLoader() {

        if (loader != null)
            return (loader);
        if (parent != null)
            return (parent.getLoader());
        return (null);

    }


    /**
     * Set the Loader with which this Container is associated.
     *
     * @param loader The newly associated loader
     */
    public synchronized void setLoader(Loader loader) {

        // Change components if necessary
        Loader oldLoader = this.loader;
        if (oldLoader == loader)
            return;
        this.loader = loader;

        // Stop the old component if necessary
        if (started && (oldLoader != null) &&
            (oldLoader instanceof Lifecycle)) {
            try {
                ((Lifecycle) oldLoader).stop();
            } catch (LifecycleException e) {
                log.error("ContainerBase.setLoader: stop: ", e);
            }
        }

        // Start the new component if necessary
        if (loader != null)
            loader.setContainer(this);
        if (started && (loader != null) &&
            (loader instanceof Lifecycle)) {
            try {
                ((Lifecycle) loader).start();
            } catch (LifecycleException e) {
                log.error("ContainerBase.setLoader: start: ", e);
            }
        }

        // Report this property change to interested listeners
        support.firePropertyChange("loader", oldLoader, this.loader);

    }


    /**
     * Return the Logger with which this Container is associated.  If there is
     * no associated Logger, return the Logger associated with our parent
     * Container (if any); otherwise return <code>null</code>.
     */
    public Log getLogger() {

        if (logger != null)
            return (logger);
        logger = LogFactory.getLog(logName());
        return (logger);

    }


    /**
     * Return the Manager with which this Container is associated.  If there is
     * no associated Manager, return the Manager associated with our parent
     * Container (if any); otherwise return <code>null</code>.
     */
    public Manager getManager() {

        if (manager != null)
            return (manager);
        if (parent != null)
            return (parent.getManager());