36 * of a memory pool is exceeding a threshold value.
37 * The notification emitted will contain the memory notification
38 * information about the detected condition:
39 * <ul>
40 * <li>The name of the memory pool.</li>
41 * <li>The memory usage of the memory pool when the notification
42 * was constructed.</li>
43 * <li>The number of times that the memory usage has crossed
44 * a threshold when the notification was constructed.
45 * For usage threshold notifications, this count will be the
46 * {@link MemoryPoolMXBean#getUsageThresholdCount usage threshold
47 * count}. For collection threshold notifications,
48 * this count will be the
49 * {@link MemoryPoolMXBean#getCollectionUsageThresholdCount
50 * collection usage threshold count}.
51 * </li>
52 * </ul>
53 *
54 * <p>
55 * A {@link CompositeData CompositeData} representing
56 * the <tt>MemoryNotificationInfo</tt> object
57 * is stored in the
58 * {@link javax.management.Notification#setUserData user data}
59 * of a {@link javax.management.Notification notification}.
60 * The {@link #from from} method is provided to convert from
61 * a <tt>CompositeData</tt> to a <tt>MemoryNotificationInfo</tt>
62 * object. For example:
63 *
64 * <blockquote><pre>
65 * Notification notif;
66 *
67 * // receive the notification emitted by MemoryMXBean and set to notif
68 * ...
69 *
70 * String notifType = notif.getType();
71 * if (notifType.equals(MemoryNotificationInfo.MEMORY_THRESHOLD_EXCEEDED) ||
72 * notifType.equals(MemoryNotificationInfo.MEMORY_COLLECTION_THRESHOLD_EXCEEDED)) {
73 * // retrieve the memory notification information
74 * CompositeData cd = (CompositeData) notif.getUserData();
75 * MemoryNotificationInfo info = MemoryNotificationInfo.from(cd);
76 * ....
77 * }
78 * </pre></blockquote>
79 *
80 * <p>
81 * The types of notifications emitted by <tt>MemoryMXBean</tt> are:
82 * <ul>
83 * <li>A {@link #MEMORY_THRESHOLD_EXCEEDED
84 * usage threshold exceeded notification}.
85 * <br>This notification will be emitted when
86 * the memory usage of a memory pool is increased and has reached
87 * or exceeded its
88 * <a href="MemoryPoolMXBean.html#UsageThreshold"> usage threshold</a> value.
89 * Subsequent crossing of the usage threshold value does not cause
90 * further notification until the memory usage has returned
91 * to become less than the usage threshold value.
92 * </li>
93 * <li>A {@link #MEMORY_COLLECTION_THRESHOLD_EXCEEDED
94 * collection usage threshold exceeded notification}.
95 * <br>This notification will be emitted when
96 * the memory usage of a memory pool is greater than or equal to its
97 * <a href="MemoryPoolMXBean.html#CollectionThreshold">
98 * collection usage threshold</a> after the Java virtual machine
99 * has expended effort in recycling unused objects in that
100 * memory pool.</li>
101 * </ul>
102 *
103 * @author Mandy Chung
104 * @since 1.5
105 *
106 */
107 public class MemoryNotificationInfo {
108 private final String poolName;
109 private final MemoryUsage usage;
110 private final long count;
111
112 /**
113 * Notification type denoting that
114 * the memory usage of a memory pool has
115 * reached or exceeded its
116 * <a href="MemoryPoolMXBean.html#UsageThreshold"> usage threshold</a> value.
117 * This notification is emitted by {@link MemoryMXBean}.
118 * Subsequent crossing of the usage threshold value does not cause
119 * further notification until the memory usage has returned
120 * to become less than the usage threshold value.
121 * The value of this notification type is
122 * <tt>java.management.memory.threshold.exceeded</tt>.
123 */
124 public static final String MEMORY_THRESHOLD_EXCEEDED =
125 "java.management.memory.threshold.exceeded";
126
127 /**
128 * Notification type denoting that
129 * the memory usage of a memory pool is greater than or equal to its
130 * <a href="MemoryPoolMXBean.html#CollectionThreshold">
131 * collection usage threshold</a> after the Java virtual machine
132 * has expended effort in recycling unused objects in that
133 * memory pool.
134 * This notification is emitted by {@link MemoryMXBean}.
135 * The value of this notification type is
136 * <tt>java.management.memory.collection.threshold.exceeded</tt>.
137 */
138 public static final String MEMORY_COLLECTION_THRESHOLD_EXCEEDED =
139 "java.management.memory.collection.threshold.exceeded";
140
141 /**
142 * Constructs a <tt>MemoryNotificationInfo</tt> object.
143 *
144 * @param poolName The name of the memory pool which triggers this notification.
145 * @param usage Memory usage of the memory pool.
146 * @param count The threshold crossing count.
147 */
148 public MemoryNotificationInfo(String poolName,
149 MemoryUsage usage,
150 long count) {
151 if (poolName == null) {
152 throw new NullPointerException("Null poolName");
153 }
154 if (usage == null) {
155 throw new NullPointerException("Null usage");
156 }
157
158 this.poolName = poolName;
159 this.usage = usage;
160 this.count = count;
161 }
162
190 }
191
192 /**
193 * Returns the number of times that the memory usage has crossed
194 * a threshold when the notification was constructed.
195 * For usage threshold notifications, this count will be the
196 * {@link MemoryPoolMXBean#getUsageThresholdCount threshold
197 * count}. For collection threshold notifications,
198 * this count will be the
199 * {@link MemoryPoolMXBean#getCollectionUsageThresholdCount
200 * collection usage threshold count}.
201 *
202 * @return the number of times that the memory usage has crossed
203 * a threshold when the notification was constructed.
204 */
205 public long getCount() {
206 return count;
207 }
208
209 /**
210 * Returns a <tt>MemoryNotificationInfo</tt> object represented by the
211 * given <tt>CompositeData</tt>.
212 * The given <tt>CompositeData</tt> must contain
213 * the following attributes:
214 * <blockquote>
215 * <table border summary="The attributes and the types the given CompositeData contains">
216 * <tr>
217 * <th align=left>Attribute Name</th>
218 * <th align=left>Type</th>
219 * </tr>
220 * <tr>
221 * <td>poolName</td>
222 * <td><tt>java.lang.String</tt></td>
223 * </tr>
224 * <tr>
225 * <td>usage</td>
226 * <td><tt>javax.management.openmbean.CompositeData</tt></td>
227 * </tr>
228 * <tr>
229 * <td>count</td>
230 * <td><tt>java.lang.Long</tt></td>
231 * </tr>
232 * </table>
233 * </blockquote>
234 *
235 * @param cd <tt>CompositeData</tt> representing a
236 * <tt>MemoryNotificationInfo</tt>
237 *
238 * @throws IllegalArgumentException if <tt>cd</tt> does not
239 * represent a <tt>MemoryNotificationInfo</tt> object.
240 *
241 * @return a <tt>MemoryNotificationInfo</tt> object represented
242 * by <tt>cd</tt> if <tt>cd</tt> is not <tt>null</tt>;
243 * <tt>null</tt> otherwise.
244 */
245 public static MemoryNotificationInfo from(CompositeData cd) {
246 if (cd == null) {
247 return null;
248 }
249
250 if (cd instanceof MemoryNotifInfoCompositeData) {
251 return ((MemoryNotifInfoCompositeData) cd).getMemoryNotifInfo();
252 } else {
253 return new MemoryNotificationInfo(cd);
254 }
255 }
256 }
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36 * of a memory pool is exceeding a threshold value.
37 * The notification emitted will contain the memory notification
38 * information about the detected condition:
39 * <ul>
40 * <li>The name of the memory pool.</li>
41 * <li>The memory usage of the memory pool when the notification
42 * was constructed.</li>
43 * <li>The number of times that the memory usage has crossed
44 * a threshold when the notification was constructed.
45 * For usage threshold notifications, this count will be the
46 * {@link MemoryPoolMXBean#getUsageThresholdCount usage threshold
47 * count}. For collection threshold notifications,
48 * this count will be the
49 * {@link MemoryPoolMXBean#getCollectionUsageThresholdCount
50 * collection usage threshold count}.
51 * </li>
52 * </ul>
53 *
54 * <p>
55 * A {@link CompositeData CompositeData} representing
56 * the {@code MemoryNotificationInfo} object
57 * is stored in the
58 * {@link javax.management.Notification#setUserData user data}
59 * of a {@link javax.management.Notification notification}.
60 * The {@link #from from} method is provided to convert from
61 * a {@code CompositeData} to a {@code MemoryNotificationInfo}
62 * object. For example:
63 *
64 * <blockquote><pre>
65 * Notification notif;
66 *
67 * // receive the notification emitted by MemoryMXBean and set to notif
68 * ...
69 *
70 * String notifType = notif.getType();
71 * if (notifType.equals(MemoryNotificationInfo.MEMORY_THRESHOLD_EXCEEDED) ||
72 * notifType.equals(MemoryNotificationInfo.MEMORY_COLLECTION_THRESHOLD_EXCEEDED)) {
73 * // retrieve the memory notification information
74 * CompositeData cd = (CompositeData) notif.getUserData();
75 * MemoryNotificationInfo info = MemoryNotificationInfo.from(cd);
76 * ....
77 * }
78 * </pre></blockquote>
79 *
80 * <p>
81 * The types of notifications emitted by {@code MemoryMXBean} are:
82 * <ul>
83 * <li>A {@link #MEMORY_THRESHOLD_EXCEEDED
84 * usage threshold exceeded notification}.
85 * <br>This notification will be emitted when
86 * the memory usage of a memory pool is increased and has reached
87 * or exceeded its
88 * <a href="MemoryPoolMXBean.html#UsageThreshold"> usage threshold</a> value.
89 * Subsequent crossing of the usage threshold value does not cause
90 * further notification until the memory usage has returned
91 * to become less than the usage threshold value.
92 * </li>
93 * <li>A {@link #MEMORY_COLLECTION_THRESHOLD_EXCEEDED
94 * collection usage threshold exceeded notification}.
95 * <br>This notification will be emitted when
96 * the memory usage of a memory pool is greater than or equal to its
97 * <a href="MemoryPoolMXBean.html#CollectionThreshold">
98 * collection usage threshold</a> after the Java virtual machine
99 * has expended effort in recycling unused objects in that
100 * memory pool.</li>
101 * </ul>
102 *
103 * @author Mandy Chung
104 * @since 1.5
105 *
106 */
107 public class MemoryNotificationInfo {
108 private final String poolName;
109 private final MemoryUsage usage;
110 private final long count;
111
112 /**
113 * Notification type denoting that
114 * the memory usage of a memory pool has
115 * reached or exceeded its
116 * <a href="MemoryPoolMXBean.html#UsageThreshold"> usage threshold</a> value.
117 * This notification is emitted by {@link MemoryMXBean}.
118 * Subsequent crossing of the usage threshold value does not cause
119 * further notification until the memory usage has returned
120 * to become less than the usage threshold value.
121 * The value of this notification type is
122 * {@code java.management.memory.threshold.exceeded}.
123 */
124 public static final String MEMORY_THRESHOLD_EXCEEDED =
125 "java.management.memory.threshold.exceeded";
126
127 /**
128 * Notification type denoting that
129 * the memory usage of a memory pool is greater than or equal to its
130 * <a href="MemoryPoolMXBean.html#CollectionThreshold">
131 * collection usage threshold</a> after the Java virtual machine
132 * has expended effort in recycling unused objects in that
133 * memory pool.
134 * This notification is emitted by {@link MemoryMXBean}.
135 * The value of this notification type is
136 * {@code java.management.memory.collection.threshold.exceeded}.
137 */
138 public static final String MEMORY_COLLECTION_THRESHOLD_EXCEEDED =
139 "java.management.memory.collection.threshold.exceeded";
140
141 /**
142 * Constructs a {@code MemoryNotificationInfo} object.
143 *
144 * @param poolName The name of the memory pool which triggers this notification.
145 * @param usage Memory usage of the memory pool.
146 * @param count The threshold crossing count.
147 */
148 public MemoryNotificationInfo(String poolName,
149 MemoryUsage usage,
150 long count) {
151 if (poolName == null) {
152 throw new NullPointerException("Null poolName");
153 }
154 if (usage == null) {
155 throw new NullPointerException("Null usage");
156 }
157
158 this.poolName = poolName;
159 this.usage = usage;
160 this.count = count;
161 }
162
190 }
191
192 /**
193 * Returns the number of times that the memory usage has crossed
194 * a threshold when the notification was constructed.
195 * For usage threshold notifications, this count will be the
196 * {@link MemoryPoolMXBean#getUsageThresholdCount threshold
197 * count}. For collection threshold notifications,
198 * this count will be the
199 * {@link MemoryPoolMXBean#getCollectionUsageThresholdCount
200 * collection usage threshold count}.
201 *
202 * @return the number of times that the memory usage has crossed
203 * a threshold when the notification was constructed.
204 */
205 public long getCount() {
206 return count;
207 }
208
209 /**
210 * Returns a {@code MemoryNotificationInfo} object represented by the
211 * given {@code CompositeData}.
212 * The given {@code CompositeData} must contain
213 * the following attributes:
214 * <blockquote>
215 * <table border summary="The attributes and the types the given CompositeData contains">
216 * <tr>
217 * <th align=left>Attribute Name</th>
218 * <th align=left>Type</th>
219 * </tr>
220 * <tr>
221 * <td>poolName</td>
222 * <td>{@code java.lang.String}</td>
223 * </tr>
224 * <tr>
225 * <td>usage</td>
226 * <td>{@code javax.management.openmbean.CompositeData}</td>
227 * </tr>
228 * <tr>
229 * <td>count</td>
230 * <td>{@code java.lang.Long}</td>
231 * </tr>
232 * </table>
233 * </blockquote>
234 *
235 * @param cd {@code CompositeData} representing a
236 * {@code MemoryNotificationInfo}
237 *
238 * @throws IllegalArgumentException if {@code cd} does not
239 * represent a {@code MemoryNotificationInfo} object.
240 *
241 * @return a {@code MemoryNotificationInfo} object represented
242 * by {@code cd} if {@code cd} is not {@code null};
243 * {@code null} otherwise.
244 */
245 public static MemoryNotificationInfo from(CompositeData cd) {
246 if (cd == null) {
247 return null;
248 }
249
250 if (cd instanceof MemoryNotifInfoCompositeData) {
251 return ((MemoryNotifInfoCompositeData) cd).getMemoryNotifInfo();
252 } else {
253 return new MemoryNotificationInfo(cd);
254 }
255 }
256 }
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