alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

What this is

This file is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Other links

The source code

/*
 *  Copyright 1999-2004 The Apache Software Foundation
 *
 *  Licensed 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.jk.common;

import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URLConnection;
import java.net.URL;
import java.util.List;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import javax.management.MBeanServer;
import javax.management.AttributeNotFoundException;
import javax.management.MBeanException;
import javax.management.ReflectionException;
import javax.management.Attribute;
import javax.management.ObjectName;

import org.apache.jk.core.JkHandler;
import org.apache.commons.modeler.Registry;
import org.apache.commons.modeler.BaseModelMBean;
import org.apache.commons.modeler.ManagedBean;
import org.apache.commons.modeler.AttributeInfo;
import org.apache.commons.modeler.OperationInfo;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * A small mbean that will act as a proxy for mod_jk2.
 *
 * For efficiency, it'll get bulk results and cache them - you
 * can force an update by calling the refreshAttributes and refreshMetadata
 * operations on this mbean.
 *
 * TODO: implement the user/pass auth ( right now you must use IP based security )
 * TODO: eventually support https
 * TODO: support for metadata ( mbean-descriptors ) for description and type conversions
 * TODO: filter out trivial components ( mutexes, etc )
 *
 * @author Costin Manolache
 */
public class ModJkMX extends JkHandler
{
    private static Log log = LogFactory.getLog(ModJkMX.class);

    MBeanServer mserver;
    String webServerHost="localhost";
    int webServerPort=80;
    String statusPath="/jkstatus";
    String user;
    String pass;
    Registry reg;

    HashMap mbeans=new HashMap();
    long lastRefresh=0;
    long updateInterval=5000; // 5 sec - it's min time between updates

    public ModJkMX()
    {
    }

    /* -------------------- Public methods -------------------- */

    public String getWebServerHost() {
        return webServerHost;
    }

    public void setWebServerHost(String webServerHost) {
        this.webServerHost = webServerHost;
    }

    public int getWebServerPort() {
        return webServerPort;
    }

    public void setWebServerPort(int webServerPort) {
        this.webServerPort = webServerPort;
    }

    public long getUpdateInterval() {
        return updateInterval;
    }

    public void setUpdateInterval(long updateInterval) {
        this.updateInterval = updateInterval;
    }

    public String getUser() {
        return user;
    }

    public void setUser(String user) {
        this.user = user;
    }

    public String getPass() {
        return pass;
    }

    public void setPass(String pass) {
        this.pass = pass;
    }

    public String getStatusPath() {
        return statusPath;
    }

    public void setStatusPath(String statusPath) {
        this.statusPath = statusPath;
    }
    /* ==================== Start/stop ==================== */

    public void destroy() {
        try {
            // We should keep track of loaded beans and call stop.
            // Modeler should do it...
            Iterator mbeansIt=mbeans.values().iterator();
            MBeanServer mbserver = Registry.getRegistry().getMBeanServer();
            while( mbeansIt.hasNext()) {
                MBeanProxy proxy=(MBeanProxy)mbeansIt.next();
                Object ooname = proxy.getObjectName();
                if( ooname != null ) {
                    ObjectName oname = null;
                    if(ooname instanceof ObjectName) {
                        oname = (ObjectName)ooname;
                    } else if(ooname instanceof String) {
                        oname = new ObjectName((String)ooname);
                    }
                    if( oname != null ) {
                        mbserver.unregisterMBean(oname);
                    }
                }
            }
        } catch( Throwable t ) {
            log.error( "Destroy error", t );
        }
    }

    public void init() throws IOException {
        try {
            //if( log.isDebugEnabled() )
            log.info("init " + webServerHost + " " + webServerPort);
            reg=Registry.getRegistry();
            refreshMetadata();
            refreshAttributes();
        } catch( Throwable t ) {
            log.error( "Init error", t );
        }
    }

    public void start() throws IOException {
        if( reg==null)
            init();
    }

    /** Refresh the proxies, if updateInterval passed
     *
     */
    public void refresh()  {
        long time=System.currentTimeMillis();
        if( time - lastRefresh < updateInterval ) {
            return;
        }
        lastRefresh=time;
        refreshMetadata();
        refreshAttributes();
    }

    public void refreshAttributes()  {
        try {
            int cnt=0;
            // connect to apache, get a list of mbeans
            BufferedReader is=getStream( "dmp=*");
            if( is==null ) return;

            String name=null;
            String att=null;
            String val=null;
            while(true) {
                String line=is.readLine();
                if( line==null ) break;
                line=line.trim();
                if( "".equals(line) || line.startsWith("#") ) continue;

                // for each mbean, create a proxy
                if(log.isDebugEnabled())
                    log.debug("Read " + line);

                if(line.startsWith( "[")) {
                    name=line.substring(1);
                    if( name.endsWith("]")) {
                        name=name.substring(0, name.length()-1);
                    }
                }
                // Name/value pair
                int idx=line.indexOf('=');
                if( idx < 0 ) continue;
                att=line.substring(0, idx );
                val=line.substring(idx+1);

                if( log.isDebugEnabled())
                    log.debug("name: " + name + " att=" + att +
                            " val=" + val);

                MBeanProxy proxy=(MBeanProxy)mbeans.get(name);
                if( proxy==null ) {
                    log.info( "Unknown object " + name);
                } else {
                    proxy.update(att, val);
                    cnt++;
                }
            }
            log.info( "Refreshing attributes " + cnt);
        } catch( Exception ex ) {
            log.info("Error ", ex);
        }
    }

    /** connect to apache, get a list of mbeans
      */
    BufferedReader getStream(String qry) throws Exception {
        try {
            String path=statusPath + "?" + qry;
            URL url=new URL( "http", webServerHost, webServerPort, path);
            URLConnection urlc=url.openConnection();
            BufferedReader is=new BufferedReader(new InputStreamReader(urlc.getInputStream()));
            return is;
        } catch (IOException e) {
            log.info( "Can't connect to jkstatus " + webServerHost + ":" + webServerPort
            + " " + e.toString());
            return null;
        }
    }

    public void refreshMetadata() {
        try {
            int cnt=0;
            int newCnt=0;
            BufferedReader is=getStream("lst=*");
            if( is==null ) return;
            String name=null;
            String type=null;
            ArrayList getters=new ArrayList();
            ArrayList setters=new ArrayList();
            ArrayList methods=new ArrayList();
            while(true) {
                String line=is.readLine();
                if( log.isDebugEnabled())
                    log.debug("Read " + line);

                // end of section
                if( line == null || line.startsWith("[") ) {
                    if( name != null ) {
                        cnt++;
                        if( mbeans.get( name ) ==null ) {
                            // New component
                            newCnt++;
                            MBeanProxy mproxy=new MBeanProxy(this);
                            mproxy.init( name, getters, setters, methods);
                            mbeans.put( name, mproxy );
                        }
                        if( log.isDebugEnabled())
                            log.debug("mbean name: " + name + " type=" + type);

                        getters.clear();
                        setters.clear();
                        methods.clear();
                    }
                }
                // end of data
                if( line==null ) break;

                line=line.trim();
                if( "".equals( line ) || line.startsWith("#"))  continue;

                // for each mbean, create a proxy

                if(line.startsWith( "[") && line.endsWith("]")) {
                    name=line.substring(1, line.length()-1);
                }
                if(line.startsWith( "T=")) {
                    type=line.substring(2);
                }
                if( line.startsWith("G=")) {
                    getters.add(line.substring(2));
                }
                if( line.startsWith("S=")) {
                    setters.add(line.substring(2));
                }
                if( line.startsWith("M=")) {
                    methods.add(line.substring(2));
                }
            }
            log.info( "Refreshing metadata " + cnt + " " +  newCnt);
        } catch( Exception ex ) {
            log.info("Error ", ex);
        }
    }

    /** Use the same metadata, except that we replace the attribute
     * get/set methods.
     */
    static class MBeanProxy extends BaseModelMBean {
        private static Log log = LogFactory.getLog(MBeanProxy.class);

        String jkName;
        List getAttNames;
        List setAttNames;
        HashMap atts=new HashMap();
        ModJkMX jkmx;

        public MBeanProxy(ModJkMX jkmx) throws Exception {
            this.jkmx=jkmx;
        }

        void init( String name, List getters, List setters, List methods )
            throws Exception
        {
            if(log.isDebugEnabled())
                log.debug("Register " + name );
            int col=name.indexOf( ':' );
            this.jkName=name;
            String type=name.substring(0, col );
            String id=name.substring(col+1);
            id=id.replace('*','%');
            id=id.replace(':', '%');
            if( id.length() == 0 ) {
                id="default";
            }
            ManagedBean mbean= new ManagedBean();

            AttributeInfo ai=new AttributeInfo();
            ai.setName( "jkName" );
            ai.setType( "java.lang.String");
            ai.setWriteable(false);
            mbean.addAttribute(ai);

            for( int i=0; i
... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.