NotificationResult


1   /*
2    * @(#)NotificationResult.java  1.6 03/12/19
3    * 
4    * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
5    * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
6    */
7   
8   package javax.management.remote;
9   
10  import java.io.Serializable  ;
11  
12  import javax.management.Notification  ;
13  import javax.management.ObjectName  ;
14  
15  /**
16   * <p>Result of a query for buffered notifications.  Notifications in
17   * a notification buffer have positive, monotonically increasing
18   * sequence numbers.  The result of a notification query contains the
19   * following elements:</p>
20   *
21   * <ul>
22   *
23   * <li>The sequence number of the earliest notification still in
24   * the buffer.
25   *
26   * <li>The sequence number of the next notification available for
27   * querying.  This will be the starting sequence number for the next
28   * notification query.
29   *
30   * <li>An array of (Notification,listenerID) pairs corresponding to
31   * the returned notifications and the listeners they correspond to.
32   *
33   * </ul>
34   *
35   * <p>It is possible for the <code>nextSequenceNumber</code> to be less
36   * than the <code>earliestSequenceNumber</code>.  This signifies that
37   * notifications between the two might have been lost.</p>
38   *
39   * @since 1.5
40   * @since.unbundled 1.0
41   */
42  public class NotificationResult implements Serializable   {
43  
44      private static final long serialVersionUID = 1191800228721395279L;
45  
46      /**
47       * <p>Constructs a notification query result.</p>
48       *
49       * @param earliestSequenceNumber the sequence number of the
50       * earliest notification still in the buffer.
51       * @param nextSequenceNumber the sequence number of the next
52       * notification available for querying.
53       * @param targetedNotifications the notifications resulting from
54       * the query, and the listeners they correspond to.  This array
55       * can be empty.
56       *
57       * @exception IllegalArgumentException if
58       * <code>targetedNotifications</code> is null or if
59       * <code>earliestSequenceNumber</code> or
60       * <code>nextSequenceNumber</code> is negative.
61       */
62      public NotificationResult(long earliestSequenceNumber,
63                    long nextSequenceNumber,
64                    TargetedNotification  [] targetedNotifications) {
65      if (targetedNotifications == null) {
66          final String   msg = "Notifications null";
67          throw new IllegalArgumentException  (msg);
68      }
69  
70      if (earliestSequenceNumber < 0 || nextSequenceNumber < 0)
71          throw new IllegalArgumentException  ("Bad sequence numbers");
72      /* We used to check nextSequenceNumber >= earliestSequenceNumber
73         here.  But in fact the opposite can legitimately be true if
74         notifications have been lost.  */
75  
76      this.earliestSequenceNumber = earliestSequenceNumber;
77      this.nextSequenceNumber = nextSequenceNumber;
78      this.targetedNotifications = targetedNotifications;
79      }
80  
81      /**
82       * Returns the sequence number of the earliest notification still
83       * in the buffer.
84       *
85       * @return the sequence number of the earliest notification still
86       * in the buffer.
87       */
88      public long getEarliestSequenceNumber() {
89      return earliestSequenceNumber;
90      }
91  
92      /**
93       * Returns the sequence number of the next notification available
94       * for querying.
95       *
96       * @return the sequence number of the next notification available
97       * for querying.
98       */
99      public long getNextSequenceNumber() {
100     return nextSequenceNumber;
101     }
102 
103     /**
104      * Returns the notifications resulting from the query, and the
105      * listeners they correspond to.
106      *
107      * @return the notifications resulting from the query, and the
108      * listeners they correspond to.  This array can be empty.
109      */
110     public TargetedNotification  [] getTargetedNotifications() {
111     return targetedNotifications;
112     }
113 
114     /**
115      * Returns a string representation of the object.  The result
116      * should be a concise but informative representation that is easy
117      * for a person to read.
118      *
119      * @return a string representation of the object.
120      */
121     public String   toString() {
122     return "NotificationResult: earliest=" + getEarliestSequenceNumber() +
123         "; next=" + getNextSequenceNumber() + "; nnotifs=" +
124         getTargetedNotifications().length;
125     }
126 
127     private final long earliestSequenceNumber;
128     private final long nextSequenceNumber;
129     private final TargetedNotification  [] targetedNotifications;
130 }
131
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Free Books Free Magazines
Popular Tags