EventHandlerMBeanProxy.java

/*******************************************************************************
 * This file is part of OpenNMS(R).
 *
 * Copyright (C) 2006-2011 The OpenNMS Group, Inc.
 * OpenNMS(R) is Copyright (C) 1999-2011 The OpenNMS Group, Inc.
 *
 * OpenNMS(R) is a registered trademark of The OpenNMS Group, Inc.
 *
 * OpenNMS(R) is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version.
 *
 * OpenNMS(R) is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with OpenNMS(R).  If not, see:
 *      http://www.gnu.org/licenses/
 *
 * For more information contact:
 *     OpenNMS(R) Licensing <license@opennms.org>
 *     http://www.opennms.org/
 *     http://www.opennms.com/
 *******************************************************************************/

package org.opennms.netmgt.eventd.adaptors;

import java.util.List;

import javax.management.InstanceNotFoundException;
import javax.management.MBeanServer;
import javax.management.MBeanServerFactory;
import javax.management.MalformedObjectNameException;
import javax.management.ObjectName;

import org.apache.commons.lang.builder.HashCodeBuilder;
import org.opennms.core.utils.ThreadCategory;
import org.opennms.netmgt.xml.event.Event;
import org.opennms.netmgt.xml.event.EventReceipt;

/**
 * This interface provides the contract that implementor must implement in order
 * to receive events from adaptors.
 *
 * @author <a href="mailto:weave@oculan.com">Brian Weaver </a>
 * @author <a href="http;//www.opennms.org">OpenNMS </a>
 * @version $Id: $
 */
public class EventHandlerMBeanProxy implements EventHandler {
    private MBeanServer m_mbserver;

    private ObjectName m_listener;

    private void findServer() throws InstanceNotFoundException {
        
        for (final MBeanServer sx : findMBeanServers()) {
            try {
                if (sx.getObjectInstance(m_listener) != null) {
                    m_mbserver = sx;
                    break;
                }
            } catch (final InstanceNotFoundException e) {
                // do nothing
            }
        }
        if (m_mbserver == null) {
            throw new InstanceNotFoundException("could not locate mbean server instance");
        }
        
    }

    private List<MBeanServer> findMBeanServers() {
        // In java 1.5 this returns a generic ArrayList
        return MBeanServerFactory.findMBeanServer(null);
    }

    /**
     * <p>Constructor for EventHandlerMBeanProxy.</p>
     *
     * @param name a {@link java.lang.String} object.
     * @throws javax.management.MalformedObjectNameException if any.
     * @throws javax.management.InstanceNotFoundException if any.
     */
    public EventHandlerMBeanProxy(final String name) throws MalformedObjectNameException, InstanceNotFoundException {
        m_listener = new ObjectName(name);
        findServer();
    }

    /**
     * <p>Constructor for EventHandlerMBeanProxy.</p>
     *
     * @param name a {@link javax.management.ObjectName} object.
     * @throws javax.management.InstanceNotFoundException if any.
     */
    public EventHandlerMBeanProxy(final ObjectName name) throws InstanceNotFoundException {
        m_listener = name;
        findServer();
    }

    /**
     * <p>Constructor for EventHandlerMBeanProxy.</p>
     *
     * @param name a {@link javax.management.ObjectName} object.
     * @param server a {@link javax.management.MBeanServer} object.
     */
    public EventHandlerMBeanProxy(final ObjectName name, final MBeanServer server) {
        m_listener = name;
        m_mbserver = server;
    }

    /** {@inheritDoc} */
    public boolean processEvent(final Event event) {
        boolean result = false;
        try {
            result = (Boolean) m_mbserver.invoke(m_listener, "processEvent", new Object[] { event }, new String[] { "org.opennms.netmgt.xml.event.Event" });
        } catch (final Throwable t) {
            ThreadCategory.getInstance(getClass()).warn("Invocation on object " + m_listener + " failed", t);
        }

        return result;
    }

    /** {@inheritDoc} */
    public void receiptSent(final EventReceipt receipt) {
        try {
            m_mbserver.invoke(m_listener, "receiptSent", new Object[] { receipt }, new String[] { "org.opennms.netmgt.xml.event.EventReceipt" });
        } catch (final Throwable t) {
            ThreadCategory.getInstance(getClass()).warn("Invocation on object " + m_listener + " failed", t);
        }
    }

    /** {@inheritDoc} */
    @Override
    public int hashCode() {
        return new HashCodeBuilder(9, 13)
            .append(m_mbserver)
            .append(m_listener)
            .toHashCode();
    }

    /** {@inheritDoc} */
    @Override
    public boolean equals(Object obj) {
        boolean rc = false;
        if (this == obj) {
            rc = true;
        } else if (obj != null && obj instanceof EventHandlerMBeanProxy) {
            EventHandlerMBeanProxy p = (EventHandlerMBeanProxy) obj;
            if (p.m_mbserver.equals(m_mbserver) && p.m_listener.equals(m_listener))
                rc = true;
        }

        return rc;
    }
}