/*
 * Copyright (c) 2003, 2007, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javax.management.remote;

import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.Serializable;

Result of a query for buffered notifications. Notifications in a notification buffer have positive, monotonically increasing sequence numbers. The result of a notification query contains the following elements:

  • The sequence number of the earliest notification still in the buffer.
  • The sequence number of the next notification available for querying. This will be the starting sequence number for the next notification query.
  • An array of (Notification,listenerID) pairs corresponding to the returned notifications and the listeners they correspond to.

It is possible for the nextSequenceNumber to be less than the earliestSequenceNumber. This signifies that notifications between the two might have been lost.

Since:1.5
/** * <p>Result of a query for buffered notifications. Notifications in * a notification buffer have positive, monotonically increasing * sequence numbers. The result of a notification query contains the * following elements:</p> * * <ul> * * <li>The sequence number of the earliest notification still in * the buffer. * * <li>The sequence number of the next notification available for * querying. This will be the starting sequence number for the next * notification query. * * <li>An array of (Notification,listenerID) pairs corresponding to * the returned notifications and the listeners they correspond to. * * </ul> * * <p>It is possible for the <code>nextSequenceNumber</code> to be less * than the <code>earliestSequenceNumber</code>. This signifies that * notifications between the two might have been lost.</p> * * @since 1.5 */
public class NotificationResult implements Serializable { private static final long serialVersionUID = 1191800228721395279L;

Constructs a notification query result.

Params:
  • earliestSequenceNumber – the sequence number of the earliest notification still in the buffer.
  • nextSequenceNumber – the sequence number of the next notification available for querying.
  • targetedNotifications – the notifications resulting from the query, and the listeners they correspond to. This array can be empty.
Throws:
  • IllegalArgumentException – if targetedNotifications is null or if earliestSequenceNumber or nextSequenceNumber is negative.
/** * <p>Constructs a notification query result.</p> * * @param earliestSequenceNumber the sequence number of the * earliest notification still in the buffer. * @param nextSequenceNumber the sequence number of the next * notification available for querying. * @param targetedNotifications the notifications resulting from * the query, and the listeners they correspond to. This array * can be empty. * * @exception IllegalArgumentException if * <code>targetedNotifications</code> is null or if * <code>earliestSequenceNumber</code> or * <code>nextSequenceNumber</code> is negative. */
public NotificationResult(long earliestSequenceNumber, long nextSequenceNumber, TargetedNotification[] targetedNotifications) { validate(targetedNotifications, earliestSequenceNumber, nextSequenceNumber); this.earliestSequenceNumber = earliestSequenceNumber; this.nextSequenceNumber = nextSequenceNumber; this.targetedNotifications = (targetedNotifications.length == 0 ? targetedNotifications : targetedNotifications.clone()); }
Returns the sequence number of the earliest notification still in the buffer.
Returns:the sequence number of the earliest notification still in the buffer.
/** * Returns the sequence number of the earliest notification still * in the buffer. * * @return the sequence number of the earliest notification still * in the buffer. */
public long getEarliestSequenceNumber() { return earliestSequenceNumber; }
Returns the sequence number of the next notification available for querying.
Returns:the sequence number of the next notification available for querying.
/** * Returns the sequence number of the next notification available * for querying. * * @return the sequence number of the next notification available * for querying. */
public long getNextSequenceNumber() { return nextSequenceNumber; }
Returns the notifications resulting from the query, and the listeners they correspond to.
Returns:the notifications resulting from the query, and the listeners they correspond to. This array can be empty.
/** * Returns the notifications resulting from the query, and the * listeners they correspond to. * * @return the notifications resulting from the query, and the * listeners they correspond to. This array can be empty. */
public TargetedNotification[] getTargetedNotifications() { return targetedNotifications.length == 0 ? targetedNotifications : targetedNotifications.clone(); }
Returns a string representation of the object. The result should be a concise but informative representation that is easy for a person to read.
Returns:a string representation of the object.
/** * Returns a string representation of the object. The result * should be a concise but informative representation that is easy * for a person to read. * * @return a string representation of the object. */
public String toString() { return "NotificationResult: earliest=" + getEarliestSequenceNumber() + "; next=" + getNextSequenceNumber() + "; nnotifs=" + getTargetedNotifications().length; } private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException { ois.defaultReadObject(); try { validate( this.targetedNotifications, this.earliestSequenceNumber, this.nextSequenceNumber ); this.targetedNotifications = this.targetedNotifications.length == 0 ? this.targetedNotifications : this.targetedNotifications.clone(); } catch (IllegalArgumentException e) { throw new InvalidObjectException(e.getMessage()); } } private long earliestSequenceNumber; private long nextSequenceNumber; private TargetedNotification[] targetedNotifications; private static void validate(TargetedNotification[] targetedNotifications, long earliestSequenceNumber, long nextSequenceNumber) throws IllegalArgumentException { if (targetedNotifications == null) { final String msg = "Notifications null"; throw new IllegalArgumentException(msg); } if (earliestSequenceNumber < 0 || nextSequenceNumber < 0) throw new IllegalArgumentException("Bad sequence numbers"); /* We used to check nextSequenceNumber >= earliestSequenceNumber here. But in fact the opposite can legitimately be true if notifications have been lost. */ } }