001 /* NotificationResult.java -- Wrapper for a series of buffered notifications.
002 Copyright (C) 2008 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038 package javax.management.remote;
039
040 import java.io.Serializable;
041
042 /**
043 * <p>
044 * Wraps the result of a query for buffered notifications. In a remote
045 * scenario, it may be more practical for the server to buffer individual
046 * notifications from its beans and then return them in bulk on request.
047 * This class contains the notifications returned by such a request.
048 * </p>
049 * <p>
050 * It consists of a series of {@link Notification} and identifier pairs,
051 * wrapped in a {@link TargetedNotification} object. The identifiers
052 * serve to pair up the notification with the listener that requested
053 * it. Two positive numbers are also included: the first sequence number
054 * used by the returned notifications, and the sequence number of the
055 * notification which will be returned by the next query. The first
056 * sequence number may be greater than the next sequence number if some
057 * notifications have been lost.
058 * </p>
059 *
060 * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
061 * @since 1.5
062 */
063 public class NotificationResult
064 implements Serializable
065 {
066
067 /**
068 * Compatible with JDK 1.6
069 */
070 private static final long serialVersionUID = 1191800228721395279L;
071
072 /**
073 * The sequence number of the first notification.
074 */
075 private long earliestSequenceNumber;
076
077 /**
078 * The sequence number of the next notification to be
079 * returned by a future query.
080 */
081 private long nextSequenceNumber;
082
083 /**
084 * The pairs of notifications and identifiers returned
085 * by the query.
086 */
087 private TargetedNotification[] targetedNotifications;
088
089 /**
090 * Constructs a new {@link NotificationResult} using the specified
091 * sequence numbers and the supplied array of notification pairs.
092 *
093 * @param startSeqNumber the sequence number of the first notification
094 * being returned.
095 * @param nextSeqNumber the sequence numbr of the next notification
096 * that will be returned from a future query.
097 * @param notifications the notification and identifier pairs. This
098 * may be empty.
099 * @throws IllegalArgumentException if a sequence number is negative
100 * or <code>notifications</code> is
101 * <code>null</code>.
102 */
103 public NotificationResult(long startSeqNumber, long nextSeqNumber,
104 TargetedNotification[] notifications)
105 {
106 if (startSeqNumber < 0)
107 throw new IllegalArgumentException("Starting sequence number is " +
108 "less than 0.");
109 if (nextSeqNumber < 0)
110 throw new IllegalArgumentException("Next sequence number is " +
111 "less than 0.");
112 if (notifications == null)
113 throw new IllegalArgumentException("The array of notifications is null.");
114 earliestSequenceNumber = startSeqNumber;
115 nextSequenceNumber = nextSeqNumber;
116 targetedNotifications = notifications;
117 }
118
119 /**
120 * Returns the sequence number of the earliest notification
121 * in the buffer.
122 *
123 * @return the sequence number of the earliest notification.
124 */
125 public long getEarliestSequenceNumber()
126 {
127 return earliestSequenceNumber;
128 }
129
130 /**
131 * Returns the sequence number of the next notification to
132 * be returned by a future query.
133 *
134 * @return the sequence number of the next notification.
135 */
136 public long getNextSequenceNumber()
137 {
138 return nextSequenceNumber;
139 }
140
141 /**
142 * Returns the notification and identifier pairs returned
143 * by the query.
144 *
145 * @return the notification and identifier pairs.
146 */
147 public TargetedNotification[] getTargetedNotifications()
148 {
149 return targetedNotifications;
150 }
151
152 /**
153 * Returns a textual representation of the object.
154 *
155 * @return a textual representation.
156 */
157 public String toString()
158 {
159 return getClass().getName() +
160 "[earliestSequenceNumber=" + earliestSequenceNumber +
161 ",nextSequenceNumber=" + nextSequenceNumber +
162 ",targetedNotifications=" + targetedNotifications +
163 "]";
164 }
165
166 }