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 * accompanied this code).

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package javax.management;

/**

 * <p>An MBean whose management interface is determined by reflection

 * on a Java interface, and that emits notifications.</p>

 *

 * <p>The following example shows how to use the public constructor

 * {@link #StandardEmitterMBean(Object, Class, NotificationEmitter)

 * StandardEmitterMBean(implementation, mbeanInterface, emitter)} to

 * create an MBean emitting notifications with any

 * implementation class name <i>Impl</i>, with a management

 * interface defined (as for current Standard MBeans) by any interface

 * <i>Intf</i>, and with any implementation of the interface

 * {@link NotificationEmitter}. The example uses the class

 * {@link NotificationBroadcasterSupport} as an implementation

 * of the interface {@link NotificationEmitter}.</p>

 *

 *     <pre>

 *     MBeanServer mbs;

 *     ...

 *     final String[] types = new String[] {"sun.disc.space","sun.disc.alarm"};

 *     final MBeanNotificationInfo info = new MBeanNotificationInfo(

 *                                          types,

 *                                          Notification.class.getName(),

 *                                          "Notification about disc info.");

 *     final NotificationEmitter emitter =

 *                    new NotificationBroadcasterSupport(info);

 *

 *     final Intf impl = new Impl(...);

 *     final Object mbean = new StandardEmitterMBean(

 *                                     impl, Intf.class, emitter);

 *     mbs.registerMBean(mbean, objectName);

 *     </pre>

 *

 * @see StandardMBean

 *

 * @since 1.6

 */

public class StandardEmitterMBean extends StandardMBean

        implements NotificationEmitter {

    private static final MBeanNotificationInfo[] NO_NOTIFICATION_INFO =

        new MBeanNotificationInfo[0];

    private final NotificationEmitter emitter;

    private final MBeanNotificationInfo[] notificationInfo;

    /**

     * <p>Make an MBean whose management interface is specified by

     * {@code mbeanInterface}, with the given implementation and

     * where notifications are handled by the given {@code NotificationEmitter}.

     * The resultant MBean implements the {@code NotificationEmitter} interface

     * by forwarding its methods to {@code emitter}.  It is legal and useful

     * for {@code implementation} and {@code emitter} to be the same object.</p>

     *

     * <p>If {@code emitter} is an instance of {@code

     * NotificationBroadcasterSupport} then the MBean's {@link #sendNotification

     * sendNotification} method will call {@code emitter.}{@link

     * NotificationBroadcasterSupport#sendNotification sendNotification}.</p>

     *

     * <p>The array returned by {@link #getNotificationInfo()} on the

     * new MBean is a copy of the array returned by

     * {@code emitter.}{@link NotificationBroadcaster#getNotificationInfo

     * getNotificationInfo()} at the time of construction.  If the array

     * returned by {@code emitter.getNotificationInfo()} later changes,

     * that will have no effect on this object's

     * {@code getNotificationInfo()}.</p>

     *

     * @param implementation the implementation of the MBean interface.

     * @param mbeanInterface a Standard MBean interface.

     * @param emitter the object that will handle notifications.

     *

     * @throws IllegalArgumentException if the {@code mbeanInterface}

     *    does not follow JMX design patterns for Management Interfaces, or

     *    if the given {@code implementation} does not implement the

     *    specified interface, or if {@code emitter} is null.

     */

    public <T> StandardEmitterMBean(T implementation, Class<T> mbeanInterface,

                                    NotificationEmitter emitter) {

        this(implementation, mbeanInterface, false, emitter);

    }

    /**

     * <p>Make an MBean whose management interface is specified by

     * {@code mbeanInterface}, with the given implementation and where

     * notifications are handled by the given {@code

     * NotificationEmitter}.  This constructor can be used to make

     * either Standard MBeans or MXBeans.  The resultant MBean

     * implements the {@code NotificationEmitter} interface by

     * forwarding its methods to {@code emitter}.  It is legal and

     * useful for {@code implementation} and {@code emitter} to be the

     * same object.</p>

     *

     * <p>If {@code emitter} is an instance of {@code

     * NotificationBroadcasterSupport} then the MBean's {@link #sendNotification

     * sendNotification} method will call {@code emitter.}{@link

     * NotificationBroadcasterSupport#sendNotification sendNotification}.</p>

     *

     * <p>The array returned by {@link #getNotificationInfo()} on the

     * new MBean is a copy of the array returned by

     * {@code emitter.}{@link NotificationBroadcaster#getNotificationInfo

     * getNotificationInfo()} at the time of construction.  If the array

     * returned by {@code emitter.getNotificationInfo()} later changes,

     * that will have no effect on this object's

     * {@code getNotificationInfo()}.</p>

     *

     * @param implementation the implementation of the MBean interface.

     * @param mbeanInterface a Standard MBean interface.

     * @param isMXBean If true, the {@code mbeanInterface} parameter

     * names an MXBean interface and the resultant MBean is an MXBean.

     * @param emitter the object that will handle notifications.

     *

     * @throws IllegalArgumentException if the {@code mbeanInterface}

     *    does not follow JMX design patterns for Management Interfaces, or

     *    if the given {@code implementation} does not implement the

     *    specified interface, or if {@code emitter} is null.

     */

    public <T> StandardEmitterMBean(T implementation, Class<T> mbeanInterface,

                                    boolean isMXBean,

                                    NotificationEmitter emitter) {

        super(implementation, mbeanInterface, isMXBean);

        if (emitter == null)

            throw new IllegalArgumentException("Null emitter");

        this.emitter = emitter;

        MBeanNotificationInfo[] infos = emitter.getNotificationInfo();

        if (infos == null || infos.length == 0) {

            this.notificationInfo = NO_NOTIFICATION_INFO;

        } else {

            this.notificationInfo = infos.clone();

        }

    }

    /**

     * <p>Make an MBean whose management interface is specified by

     * {@code mbeanInterface}, and

     * where notifications are handled by the given {@code NotificationEmitter}.

     * The resultant MBean implements the {@code NotificationEmitter} interface

     * by forwarding its methods to {@code emitter}.</p>

     *

     * <p>If {@code emitter} is an instance of {@code

     * NotificationBroadcasterSupport} then the MBean's {@link #sendNotification

     * sendNotification} method will call {@code emitter.}{@link

     * NotificationBroadcasterSupport#sendNotification sendNotification}.</p>

     *

     * <p>The array returned by {@link #getNotificationInfo()} on the

     * new MBean is a copy of the array returned by

     * {@code emitter.}{@link NotificationBroadcaster#getNotificationInfo

     * getNotificationInfo()} at the time of construction.  If the array

     * returned by {@code emitter.getNotificationInfo()} later changes,

     * that will have no effect on this object's

     * {@code getNotificationInfo()}.</p>

     *

     * <p>This constructor must be called from a subclass that implements

     * the given {@code mbeanInterface}.</p>

     *

     * @param mbeanInterface a StandardMBean interface.

     * @param emitter the object that will handle notifications.

     *

     * @throws IllegalArgumentException if the {@code mbeanInterface}

     *    does not follow JMX design patterns for Management Interfaces, or

     *    if {@code this} does not implement the specified interface, or

     *    if {@code emitter} is null.

     */

    protected StandardEmitterMBean(Class<?> mbeanInterface,

                                   NotificationEmitter emitter) {

        this(mbeanInterface, false, emitter);

    }

    /**

     * <p>Make an MBean whose management interface is specified by

     * {@code mbeanInterface}, and where notifications are handled by

     * the given {@code NotificationEmitter}.  This constructor can be

     * used to make either Standard MBeans or MXBeans.  The resultant

     * MBean implements the {@code NotificationEmitter} interface by

     * forwarding its methods to {@code emitter}.</p>

     *

     * <p>If {@code emitter} is an instance of {@code

     * NotificationBroadcasterSupport} then the MBean's {@link #sendNotification

     * sendNotification} method will call {@code emitter.}{@link

     * NotificationBroadcasterSupport#sendNotification sendNotification}.</p>

     *

     * <p>The array returned by {@link #getNotificationInfo()} on the

     * new MBean is a copy of the array returned by

     * {@code emitter.}{@link NotificationBroadcaster#getNotificationInfo

     * getNotificationInfo()} at the time of construction.  If the array

     * returned by {@code emitter.getNotificationInfo()} later changes,

     * that will have no effect on this object's

     * {@code getNotificationInfo()}.</p>

     *

     * <p>This constructor must be called from a subclass that implements

     * the given {@code mbeanInterface}.</p>

     *

     * @param mbeanInterface a StandardMBean interface.

     * @param isMXBean If true, the {@code mbeanInterface} parameter

     * names an MXBean interface and the resultant MBean is an MXBean.

     * @param emitter the object that will handle notifications.

     *

     * @throws IllegalArgumentException if the {@code mbeanInterface}

     *    does not follow JMX design patterns for Management Interfaces, or

     *    if {@code this} does not implement the specified interface, or

     *    if {@code emitter} is null.

     */

    protected StandardEmitterMBean(Class<?> mbeanInterface, boolean isMXBean,

                                   NotificationEmitter emitter) {

        super(mbeanInterface, isMXBean);

        if (emitter == null)

            throw new IllegalArgumentException("Null emitter");

        this.emitter = emitter;

        MBeanNotificationInfo[] infos = emitter.getNotificationInfo();

        if (infos == null || infos.length == 0) {

            this.notificationInfo = NO_NOTIFICATION_INFO;

        } else {

            this.notificationInfo = infos.clone();

        }

    }

    public void removeNotificationListener(NotificationListener listener)

            throws ListenerNotFoundException {

        emitter.removeNotificationListener(listener);

    }

    public void removeNotificationListener(NotificationListener listener,

                                           NotificationFilter filter,

                                           Object handback)

            throws ListenerNotFoundException {

        emitter.removeNotificationListener(listener, filter, handback);

    }

    public void addNotificationListener(NotificationListener listener,

                                        NotificationFilter filter,

                                        Object handback) {

        emitter.addNotificationListener(listener, filter, handback);

    }

    public MBeanNotificationInfo[] getNotificationInfo() {

        // this getter might get called from the super constructor

        // when the notificationInfo has not been properly set yet

        if (notificationInfo == null) {

            return NO_NOTIFICATION_INFO;

        }

        if (notificationInfo.length == 0) {

            return notificationInfo;

        } else {

            return notificationInfo.clone();

        }

    }

    /**

     * <p>Sends a notification.</p>

     *

     * <p>If the {@code emitter} parameter to the constructor was an

     * instance of {@code NotificationBroadcasterSupport} then this

     * method will call {@code emitter.}{@link

     * NotificationBroadcasterSupport#sendNotification

     * sendNotification}.</p>

     *

     * @param n the notification to send.

     *

     * @throws ClassCastException if the {@code emitter} parameter to the

     * constructor was not a {@code NotificationBroadcasterSupport}.

     */

    public void sendNotification(Notification n) {

        if (emitter instanceof NotificationBroadcasterSupport)

            ((NotificationBroadcasterSupport) emitter).sendNotification(n);

        else {

            final String msg =

                "Cannot sendNotification when emitter is not an " +

                "instance of NotificationBroadcasterSupport: " +

                emitter.getClass().getName();

            throw new ClassCastException(msg);

        }

    }

    /**

     * <p>Get the MBeanNotificationInfo[] that will be used in the

     * MBeanInfo returned by this MBean.</p>

     *

     * <p>The default implementation of this method returns

     * {@link #getNotificationInfo()}.</p>

     *

     * @param info The default MBeanInfo derived by reflection.

     * @return the MBeanNotificationInfo[] for the new MBeanInfo.

     */

    @Override

    MBeanNotificationInfo[] getNotifications(MBeanInfo info) {

        return getNotificationInfo();

    }

}