1 /* NotificationResult.java -- Wrapper for a series of buffered notifications.
2    Copyright (C) 2008 Free Software Foundation, Inc.
3 
4 This file is part of GNU Classpath.
5 
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10 
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 General Public License for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING.  If not, write to the
18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19 02110-1301 USA.
20 
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library.  Thus, the terms and
23 conditions of the GNU General Public License cover the whole
24 combination.
25 
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module.  An independent module is a module which is not derived from
33 or based on this library.  If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so.  If you do not wish to do so, delete this
36 exception statement from your version. */
37 
38 package javax.management.remote;
39 
40 import java.io.Serializable;
41 
42 /**
43  * <p>
44  * Wraps the result of a query for buffered notifications.  In a remote
45  * scenario, it may be more practical for the server to buffer individual
46  * notifications from its beans and then return them in bulk on request.
47  * This class contains the notifications returned by such a request.
48  * </p>
49  * <p>
50  * It consists of a series of {@link Notification} and identifier pairs,
51  * wrapped in a {@link TargetedNotification} object.  The identifiers
52  * serve to pair up the notification with the listener that requested
53  * it.  Two positive numbers are also included: the first sequence number
54  * used by the returned notifications, and the sequence number of the
55  * notification which will be returned by the next query.  The first
56  * sequence number may be greater than the next sequence number if some
57  * notifications have been lost.
58  * </p>
59  *
60  * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
61  * @since 1.5
62  */
63 public class NotificationResult
64   implements Serializable
65 {
66 
67   /**
68    * Compatible with JDK 1.6
69    */
70   private static final long serialVersionUID = 1191800228721395279L;
71 
72   /**
73    * The sequence number of the first notification.
74    */
75   private long earliestSequenceNumber;
76 
77   /**
78    * The sequence number of the next notification to be
79    * returned by a future query.
80    */
81   private long nextSequenceNumber;
82 
83   /**
84    * The pairs of notifications and identifiers returned
85    * by the query.
86    */
87   private TargetedNotification[] targetedNotifications;
88 
89   /**
90    * Constructs a new {@link NotificationResult} using the specified
91    * sequence numbers and the supplied array of notification pairs.
92    *
93    * @param startSeqNumber the sequence number of the first notification
94    *                       being returned.
95    * @param nextSeqNumber the sequence numbr of the next notification
96    *                      that will be returned from a future query.
97    * @param notifications the notification and identifier pairs.  This
98    *                      may be empty.
99    * @throws IllegalArgumentException if a sequence number is negative
100    *                                  or <code>notifications</code> is
101    *                                  <code>null</code>.
102    */
NotificationResult(long startSeqNumber, long nextSeqNumber, TargetedNotification[] notifications)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    */
getEarliestSequenceNumber()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    */
getNextSequenceNumber()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    */
getTargetedNotifications()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    */
toString()157   public String toString()
158   {
159     return getClass().getName() +
160       "[earliestSequenceNumber=" + earliestSequenceNumber +
161       ",nextSequenceNumber=" + nextSequenceNumber +
162       ",targetedNotifications=" + targetedNotifications +
163       "]";
164   }
165 
166 }
167