mapperlistener.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.connector;

import java.util.Iterator;
import java.util.Set;

import javax.management.MBeanServer;
import javax.management.MBeanServerNotification;
import javax.management.Notification;
import javax.management.NotificationListener;
import javax.management.ObjectInstance;
import javax.management.ObjectName;

import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;


import org.apache.tomcat.util.http.mapper.Mapper;
import org.apache.tomcat.util.modeler.Registry;

import org.apache.tomcat.util.res.StringManager;


/**
 * Mapper listener.
 *
 * @author Remy Maucherat
 * @author Costin Manolache
 */
public class MapperListener
    implements NotificationListener 
 {
    private static Log log = LogFactory.getLog(MapperListener.class);


    // ----------------------------------------------------- Instance Variables
    /**
     * Associated mapper.
     */
    protected Mapper mapper = null;

    /**
     * MBean server.
     */
    protected MBeanServer mBeanServer = null;


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

    // It should be null - and fail if not set
    private String domain="*";
    private String engine="*";

    // ----------------------------------------------------------- Constructors


    /**
     * Create mapper listener.
     */
    public MapperListener(Mapper mapper) {
        this.mapper = mapper;
    }


    // --------------------------------------------------------- Public Methods

    public String getDomain() {
        return domain;
    }

    public void setDomain(String domain) {
        this.domain = domain;
    }

    public String getEngine() {
        return engine;
    }

    public void setEngine(String engine) {
        this.engine = engine;
    }

    /**
     * Initialize associated mapper.
     */
    public void init() {

        try {

            mBeanServer = Registry.getRegistry(null, null).getMBeanServer();

            registerEngine();

            // Query hosts
            String onStr = domain + ":type=Host,*";
            ObjectName objectName = new ObjectName(onStr);
            Set set = mBeanServer.queryMBeans(objectName, null);
            Iterator iterator = set.iterator();
            while (iterator.hasNext()) {
                ObjectInstance oi = (ObjectInstance) iterator.next();
                registerHost(oi.getObjectName());
            }


            // Query contexts
            onStr = "*:j2eeType=WebModule,*";
            objectName = new ObjectName(onStr);
            set = mBeanServer.queryMBeans(objectName, null);
            iterator = set.iterator();
            while (iterator.hasNext()) {
                ObjectInstance oi = (ObjectInstance) iterator.next();
                registerContext(oi.getObjectName());
            }

            // Query wrappers
            onStr = "*:j2eeType=Servlet,*";
            objectName = new ObjectName(onStr);
            set = mBeanServer.queryMBeans(objectName, null);
            iterator = set.iterator();
            while (iterator.hasNext()) {
                ObjectInstance oi = (ObjectInstance) iterator.next();
                registerWrapper(oi.getObjectName());
            }

            onStr = "JMImplementation:type=MBeanServerDelegate";
            objectName = new ObjectName(onStr);
            mBeanServer.addNotificationListener(objectName, this, null, null);

        } catch (Exception e) {
            log.warn("Error registering contexts",e);
        }

    }

    /**
     * unregister this from JMImplementation:type=MBeanServerDelegate
     */
    public void destroy() {
        try {

            ObjectName objectName = new ObjectName(
                    "JMImplementation:type=MBeanServerDelegate");
            mBeanServer.removeNotificationListener(objectName, this);
        } catch (Exception e) {
            log.warn("Error unregistering MBeanServerDelegate", e);
        }
    }

    // ------------------------------------------- NotificationListener Methods


    public void handleNotification(Notification notification,
                                   java.lang.Object handback) {

        if (notification instanceof MBeanServerNotification) {
            ObjectName objectName = 
                ((MBeanServerNotification) notification).getMBeanName();
            String j2eeType = objectName.getKeyProperty("j2eeType");
            String engineName = null;
            if (j2eeType != null) {
                if ((j2eeType.equals("WebModule")) || 
                    (j2eeType.equals("Servlet"))) {
                    if (mBeanServer.isRegistered(objectName)) {
                        try {
                            engineName = (String)
                                mBeanServer.getAttribute(objectName, "engineName");
                        } catch (Exception e) {
                            // Ignore  
                        }
                    }
                }
            }

            // At deployment time, engineName is always = null.
            if ( (!"*".equals(domain)) &&
                 ( !domain.equals(objectName.getDomain()) ) &&
                 ( (!domain.equals(engineName) ) &&
                   (engineName != null) ) )  {
                return;
            }
            if(log.isDebugEnabled())
                log.debug( "Handle " + objectName  + " type : " + notification.getType());    
            if (notification.getType().equals
                (MBeanServerNotification.REGISTRATION_NOTIFICATION)) {
                String type=objectName.getKeyProperty("type");
                if( "Host".equals( type ) && domain.equals(objectName.getDomain())) {
                    try {
                        registerHost(objectName);
                    } catch (Exception e) {
                        log.warn("Error registering Host " + objectName, e);  
                    }
                }
    
                if (j2eeType != null) {
                    if (j2eeType.equals("WebModule")) {
                        try {
                            registerContext(objectName);
                        } catch (Throwable t) {
                            log.warn("Error registering Context " + objectName,t);
                        }
                    } else if (j2eeType.equals("Servlet")) {
                        try {
                            registerWrapper(objectName);
                        } catch (Throwable t) {
                            log.warn("Error registering Wrapper " + objectName,t);
                        }
                    }
                }
            } else if (notification.getType().equals
                       (MBeanServerNotification.UNREGISTRATION_NOTIFICATION)) {
                String type=objectName.getKeyProperty("type");
                if( "Host".equals( type )&& domain.equals(objectName.getDomain())) {
                    try {
                        unregisterHost(objectName);
                    } catch (Exception e) {
                        log.warn("Error unregistering Host " + objectName,e);  
                    }
                }
 
                if (j2eeType != null) {
                    if (j2eeType.equals("WebModule")) {
                        try {
                            unregisterContext(objectName);
                        } catch (Throwable t) {
                            log.warn("Error unregistering webapp " + objectName,t);
                        }
                    }
                }
            }
        }

    }