Commons Modeler example source code file (MLETTask.java)

This example Commons Modeler source code file (MLETTask.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 - Commons Modeler tags/keywords

arg, arg, arraylist, arraylist, jmxset, list, management, mbeanserver, mlet, mlettask, net, network, object, objectname, objectname, string, string, util

The Commons Modeler MLETTask.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.commons.modeler.ant;

import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import javax.management.JMException;
import javax.management.MBeanServer;
import javax.management.MBeanServerFactory;
import javax.management.ObjectName;
import javax.management.loading.MLet;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Task;

/**
 * Load an MBean. The syntax is similar with the <mlet>, with few
 * ant-specific extensions.
 *
 * A separate classloader can be used, the mechanism is similar with
 * what taskdef is using.
 *
 * Note that mlet will use the arguments in the constructor.
 *
 *
 */
public class MLETTask extends Task {
    private static Log log = LogFactory.getLog(MLETTask.class);
    String code;
    String archive;
    String codebase;
    String objectName;
    ObjectName oname;

    List args=new ArrayList();
    List attributes=new ArrayList();

    // ant specific
    String loaderRef; // class loader ref

    public MLETTask() {
    }

    public void addArg(Arg arg ) {
        args.add(arg);
    }

    public void addAttribute( JmxSet arg ) {
        attributes.add( arg );
    }


    public void setCode(String code) {
        this.code = code;
    }

    public void setArchive(String archive) {
        this.archive = archive;
    }

    public void setCodebase(String codebase) {
        this.codebase = codebase;
    }

    public void setName(String name) {
        this.objectName = name;
    }

    MBeanServer server;

    public MBeanServer getMBeanServer() {
        if( server!= null ) return server;

        server=(MBeanServer)project.getReference("jmx.server");

        if (server != null) return server;

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

                // Register a loader that will be find ant classes.
                ObjectName defaultLoader= new ObjectName("modeler-ant",
                        "loader", "ant");
                MLet mlet=new MLet( new URL[0], this.getClass().getClassLoader());
                server.registerMBean(mlet, defaultLoader);

                if( log.isDebugEnabled())
                    log.debug("Creating mbean server and loader "+ mlet +
                            " " + this.getClass().getClassLoader());
            }
            project.addReference("jmx.server", server);

            // Create the MLet object
        } catch( JMException ex ) {
            log.error("Error creating server", ex);
        }

        if( log.isDebugEnabled()) log.debug("Using Mserver " + server );

        return server;
    }

    boolean modeler=false;

    public void setModeler(boolean modeler) {
        this.modeler = modeler;
    }

    protected void bindJmx(String objectName, String code,
                           String arg0, List args)
            throws Exception
    {
        MBeanServer server=getMBeanServer();
        oname=new ObjectName( objectName );
        if( modeler ) {
            Arg codeArg=new Arg();
            codeArg.setType("java.lang.String");
            codeArg.setValue( code );
            if( args==null) args=new ArrayList();
            args.add(0, codeArg);
            code="org.apache.commons.modeler.BaseModelMBean";
        }

        Object argsA[]=new Object[ args.size()];
        String sigA[]=new String[args.size()];
        for( int i=0; i<args.size(); i++ ) {
            Arg arg=(Arg)args.get(i);
            if( arg.type==null )
                arg.type="java.lang.String";
            sigA[i]=arg.getType();
            argsA[i]=arg.getValue();
            // XXX Deal with not string types - IntrospectionUtils
        }

        // XXX Use the loader ref, if any
        if( args.size()==0 ) {
            server.createMBean(code, oname);
        } else {
            server.createMBean(code, oname, argsA, sigA );
        }
        log.debug( "Created MBEAN " + oname + " " + code);
    }

    public ObjectName getObjectName() {
        return oname;
    }

    public void execute() throws BuildException {
        try {
            // create the mbean
            bindJmx( objectName, code, null, args);

            // process attributes
            for( int i=0; i<attributes.size(); i++ ) {
                JmxSet att=(JmxSet)attributes.get(i);
                att.setObjectName( oname );
                log.info("Setting attribute " + oname + " " + att.getName());
                att.execute();
            }
        } catch(Exception ex) {
            log.error("Can't create mbean " + objectName, ex);
        }
    }

}