Tomcat example source code file (JkMX.java)

This example Tomcat source code file (JkMX.java) 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.

Java - Tomcat tags/keywords

attribute, attribute, can't, integer, io, management, mbeanserver, mx4j, object, objectname, objectname, port, string, string, throwable, throwable

The Tomcat JkMX.java source code

/*
 *  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.jk.common;


import org.apache.jk.core.JkHandler;

import javax.management.MBeanServer;
import javax.management.ObjectName;
import javax.management.Attribute;
import javax.management.MBeanServerFactory;
import java.io.IOException;

/**
 * Load the HTTP or RMI adapters for MX4J and JMXRI.
 *
 * Add "mx.enabled=true" in jk2.properties to enable it.
 * You could also select http and/or jrmp protocol, 
 * with mx.httpPort, mx.httpHost, mxjrmpPort and mx.jrmpPort.
 * <p />
 * If you run into an error message like
 * "SystemId Unknown; Line #12; Column #81; Cannot add attribute name after
 * child nodes or before an element is produced.  Attribute will be ignored."
 * after setting mx.enabled to true, you probably need a newer version
 * of Xalan.  See the RELEASE-NOTES document section on XML Parsers for
 * more information.
 *
 */
public class JkMX extends JkHandler
{
    MBeanServer mserver;
    private boolean enabled=false;
    private boolean log4jEnabled=true;
    private int httpport=-1;
    private String httphost="localhost";
    private String authmode="none";
    private String authuser=null;
    private String authpassword=null;
    private int jrmpport=-1;
    private String jrmphost="localhost";
    private boolean useXSLTProcessor = true;

    public JkMX() {
    }

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

    /** Enable the MX4J adapters (new way)
     */
    public void setEnabled(boolean b) {
        enabled=b;
    }
        
    public boolean getEnabled() {
        return enabled;
    }
        
    /** Enable the Log4j MBean)
     */
    public void setLog4jEnabled(boolean b) {
        log4jEnabled=b;
    }
        
    public boolean getLog4jEnabled() {
        return log4jEnabled;
    }

    /** Enable the MX4J adapters (old way, compatible)
     */
    public void setPort(int i) {
        enabled=(i != -1);
    }
        
    public int getPort() {
        return ((httpport != -1) ? httpport : jrmpport);
    }

    /** Enable the MX4J HTTP internal adapter
     */ 
    public void setHttpPort( int i ) {
        httpport=i;
    }

    public int getHttpPort() {
        return httpport;
    }

    public void setHttpHost(String host ) {
        this.httphost=host;
    }

    public String getHttpHost() {
        return httphost;
    }

    public void setAuthMode(String mode) {
        authmode=mode;
    }

    public String getAuthMode() {
        return authmode;
    }

    public void setAuthUser(String user) {
        authuser=user;
    }

    public String getAuthUser() {
        return authuser;
    }

    public void setAuthPassword(String password) {
        authpassword=password;
    }

    public String getAuthPassword() {
        return authpassword;
    }

    /** Enable the MX4J JRMP internal adapter
     */
    public void setJrmpPort( int i ) {
        jrmpport=i;
    }

    public int getJrmpPort() {
        return jrmpport;
    }

    public void setJrmpHost(String host ) {
        this.jrmphost=host;
    }

    public String getJrmpHost() {
        return jrmphost;
    }

    public boolean getUseXSLTProcessor() {
        return useXSLTProcessor;
    }

    public void setUseXSLTProcessor(boolean uxsltp) {
        useXSLTProcessor = uxsltp;
    }        

    /* ==================== Start/stop ==================== */
    ObjectName httpServerName=null;
    ObjectName jrmpServerName=null;

    /** Initialize the worker. After this call the worker will be
     *  ready to accept new requests.
     */
    public void loadAdapter() throws IOException {
        boolean httpAdapterLoaded = false;
        boolean jrmpAdapterLoaded = false;
        
        if ((httpport != -1) && classExists("mx4j.adaptor.http.HttpAdaptor")) {
            try {
                httpServerName = registerObject("mx4j.adaptor.http.HttpAdaptor",
                                                "Http:name=HttpAdaptor");

                        
                if( httphost!=null )
                    mserver.setAttribute(httpServerName, new Attribute("Host", httphost));
                mserver.setAttribute(httpServerName, new Attribute("Port", new Integer(httpport)));

                if( "none".equals(authmode) || "basic".equals(authmode) || "digest".equals(authmode) )
                    mserver.setAttribute(httpServerName, new Attribute("AuthenticationMethod", authmode));

                if( authuser!=null && authpassword!=null )
                    mserver.invoke(httpServerName, "addAuthorization",
                        new Object[] {
                            authuser,
                            authpassword},
                        new String[] { "java.lang.String", "java.lang.String" });

                if(useXSLTProcessor) {
                    ObjectName processorName = registerObject("mx4j.adaptor.http.XSLTProcessor",
                                                          "Http:name=XSLTProcessor");
                    mserver.setAttribute(httpServerName, new Attribute("ProcessorName", processorName));
                }

                // starts the server
                mserver.invoke(httpServerName, "start", null, null);

                log.info( "Started MX4J console on host " + httphost + " at port " + httpport);
                
                httpAdapterLoaded = true;

            } catch( Throwable t ) {
                httpServerName=null;
                log.error( "Can't load the MX4J http adapter ", t );
            }
        }

        if ((httpport != -1) && (!httpAdapterLoaded) && classExists("mx4j.tools.adaptor.http.HttpAdaptor")) {
            try {
                httpServerName = registerObject("mx4j.tools.adaptor.http.HttpAdaptor",
                                                "Http:name=HttpAdaptor");

                        
                if( httphost!=null )
                    mserver.setAttribute(httpServerName, new Attribute("Host", httphost));
                mserver.setAttribute(httpServerName, new Attribute("Port", new Integer(httpport)));

                if( "none".equals(authmode) || "basic".equals(authmode) || "digest".equals(authmode) )
                    mserver.setAttribute(httpServerName, new Attribute("AuthenticationMethod", authmode));

                if( authuser!=null && authpassword!=null )
                    mserver.invoke(httpServerName, "addAuthorization",
                        new Object[] {
                            authuser,
                            authpassword},
                        new String[] { "java.lang.String", "java.lang.String" });

               if(useXSLTProcessor) {
                    ObjectName processorName = registerObject("mx4j.tools.adaptor.http.XSLTProcessor",
                                                          "Http:name=XSLTProcessor");
                    mserver.setAttribute(httpServerName, new Attribute("ProcessorName", processorName));
		}
                // starts the server
                mserver.invoke(httpServerName, "start", null, null);
                if(log.isInfoEnabled())
                    log.info( "Started MX4J console on host " + httphost + " at port " + httpport);
                
                httpAdapterLoaded = true;

            } catch( Throwable t ) {
                httpServerName=null;
                log.error( "Can't load the MX4J http adapter ", t );
            }
        }

        if ((jrmpport != -1) && classExists("mx4j.tools.naming.NamingService")) {
            try {
                jrmpServerName = registerObject("mx4j.tools.naming.NamingService",
                                                "Naming:name=rmiregistry");
				mserver.setAttribute(jrmpServerName, new Attribute("Port", 
				                                     new Integer(jrmpport)));
                mserver.invoke(jrmpServerName, "start", null, null);
                if(log.isInfoEnabled())
                    log.info( "Creating " + jrmpServerName );

                // Create the JRMP adaptor
                ObjectName adaptor = registerObject("mx4j.adaptor.rmi.jrmp.JRMPAdaptor",
                                                    "Adaptor:protocol=jrmp");


                mserver.setAttribute(adaptor, new Attribute("JNDIName", "jrmp"));

                mserver.invoke( adaptor, "putNamingProperty",
                        new Object[] {
                            javax.naming.Context.INITIAL_CONTEXT_FACTORY,
                            "com.sun.jndi.rmi.registry.RegistryContextFactory"},
                        new String[] { "java.lang.Object", "java.lang.Object" });

                String jrpmurl = "rmi://" + jrmphost + ":" + Integer.toString(jrmpport) ;
                                        
                mserver.invoke( adaptor, "putNamingProperty",
                        new Object[] {
                            javax.naming.Context.PROVIDER_URL,
                            jrpmurl},
                        new String[] { "java.lang.Object", "java.lang.Object" });

                // Registers the JRMP adaptor in JNDI and starts it
                mserver.invoke(adaptor, "start", null, null);
                if(log.isInfoEnabled())
                    log.info( "Creating " + adaptor + " on host " + jrmphost + " at port " + jrmpport);

                jrmpAdapterLoaded = true;

            } catch( Exception ex ) {
                jrmpServerName = null;
                log.error( "MX4j RMI adapter not loaded: " + ex.toString());
            }
        }

        if ((httpport != -1) && (! httpAdapterLoaded) && classExists("com.sun.jdmk.comm.HtmlAdaptorServer")) {
            try {
                httpServerName=registerObject("com.sun.jdmk.comm.HtmlAdaptorServer",
                                              "Adaptor:name=html,port=" + httpport);
                if(log.isInfoEnabled())
                    log.info("Registering the JMX_RI html adapter " + httpServerName + " at port " + httpport);

                mserver.setAttribute(httpServerName,
                                     new Attribute("Port", new Integer(httpport)));

                mserver.invoke(httpServerName, "start", null, null);

                httpAdapterLoaded = true;
            } catch( Throwable t ) {
                httpServerName = null;
                log.error( "Can't load the JMX_RI http adapter " + t.toString()  );
            }
        }

        if ((!httpAdapterLoaded) && (!jrmpAdapterLoaded))
            log.warn( "No adaptors were loaded but mx.enabled was defined.");

    }

    public void destroy() {
        try {
            if(log.isInfoEnabled())
                log.info("Stoping JMX ");

            if( httpServerName!=null ) {
                mserver.invoke(httpServerName, "stop", null, null);
            }
            if( jrmpServerName!=null ) {
                mserver.invoke(jrmpServerName, "stop", null, null);
            }
        } catch( Throwable t ) {
            log.error( "Destroy error" + t );
        }
    }

    public void init() throws IOException {
        try {
            mserver = getMBeanServer();

            if( enabled ) {
                loadAdapter();
            }
            if( log4jEnabled) {
                try {
                    registerObject("org.apache.log4j.jmx.HierarchyDynamicMBean" ,
                                   "log4j:hierarchy=default");
                    if(log.isInfoEnabled())
                         log.info("Registering the JMX hierarchy for Log4J ");
                } catch( Throwable t ) {
                    if(log.isInfoEnabled())
                        log.info("Can't enable log4j mx: ",t);
                }
            }
        } catch( Throwable t ) {
            log.error( "Init error", t );
        }
    }

    public void addHandlerCallback( JkHandler w ) {
    }

    MBeanServer getMBeanServer() {
        MBeanServer server;
        if( MBeanServerFactory.findMBeanServer(null).size() > 0 ) {
            server=(MBeanServer)MBeanServerFactory.findMBeanServer(null).get(0);
        } else {
            server=MBeanServerFactory.createMBeanServer();
        }
        return (server);
    }


    private static boolean classExists(String className) {
        try {
            Thread.currentThread().getContextClassLoader().loadClass(className);
            return true;
        } catch(Throwable e) {
            if (log.isInfoEnabled())
                log.info( "className [" + className + "] does not exist");
            return false;
        }
    }

    private ObjectName registerObject(String className, String oName) 
        throws Exception {
        Class c = Class.forName(className);
        Object o = c.newInstance();
        ObjectName objN = new ObjectName(oName);
        mserver.registerMBean(o, objN);
        return objN;
    }

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


}