Groovy example source code file (JmxEventEmitter.java)

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Java - Groovy tags/keywords

atomiclong, atomiclong, event, jmxeventemitter, jmxeventemittermbean, management, notification, notification, notificationbroadcastersupport, notificationbroadcastersupport, numbersequencer, string, string

The Groovy JmxEventEmitter.java source code

/*
 * Copyright 2008 the original author or authors.
 *
 * 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 groovy.jmx.builder;

import javax.management.Notification;
import javax.management.NotificationBroadcasterSupport;
import java.util.concurrent.atomic.AtomicLong;

/**
 * The JmxEventEmitter is a JMX Broadcaster class that is used to send generic events on the MBeanServer's
 * event bus.  It is used by the Emitter node () to send event to registered listeners.
 * <p/>
 * <pre>
 *     def jmx = JmxBuilder()
 *     jmx.emitter(name:"Object name"|ObjectName(), event:"event type")
 *     ...
 *     jmx.emitter.send(object)
 * </pre>
 *
 * @author Vladimir Vivien
 * @see groovy.jmx.builder.JmxEmitterFactory
 */
public class JmxEventEmitter extends NotificationBroadcasterSupport implements JmxEventEmitterMBean {
    private String event;
    private String message;

    /**
     * Event type getter
     *
     * @return - returns event type string thrown by this emitter
     */
    public String getEvent() {
        return event;
    }

    /**
     * Event type setter
     *
     * @param event - event type set for this emitter.
     */
    public void setEvent(String event) {
        this.event = event;
    }

    /**
     * Event message getter
     *
     * @return - message that is associated with event.
     */
    public String getMessage() {
        return message;
    }

    /**
     * Event message setter.
     *
     * @param message - message that is associated with event emitted.
     */
    public void setMessage(String message) {
        this.message = message;
    }

    /**
     * Called to broadcast message on MBeanServer event bus.  Internally, it calls
     * NotificationBroadCasterSupport.sendNotification() method to dispatch the event.
     *
     * @param data - a data object sent as part of the event parameter.
     * @return a sequence number associated with the emitted event.
     */
    public long send(Object data) {
        long seq = NumberSequencer.getNextSequence();
        Notification note = new Notification(
                this.getEvent(),
                this,
                seq,
                System.currentTimeMillis(),
                "Event notification " + this.getEvent()
        );
        note.setUserData(data);
        super.sendNotification(note);
        return seq;
    }

    private static class NumberSequencer {
        private static AtomicLong num;

        static {
            num = new AtomicLong(0);
        }

        public static long getNextSequence() {
            return num.incrementAndGet();
        }
    }
}