1 /*
2 * Copyright (c) 1999, 2006, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.management;
27
28 import java.util.Arrays;
29 import java.util.Objects;
30
31 /**
32 * <p>The <CODE>MBeanNotificationInfo</CODE> class is used to describe the
33 * characteristics of the different notification instances
34 * emitted by an MBean, for a given Java class of notification.
35 * If an MBean emits notifications that can be instances of different Java classes,
36 * then the metadata for that MBean should provide an <CODE>MBeanNotificationInfo</CODE>
37 * object for each of these notification Java classes.</p>
38 *
39 * <p>Instances of this class are immutable. Subclasses may be
40 * mutable but this is not recommended.</p>
41 *
42 * <p>This class extends <CODE>javax.management.MBeanFeatureInfo</CODE>
43 * and thus provides <CODE>name</CODE> and <CODE>description</CODE> fields.
44 * The <CODE>name</CODE> field should be the fully qualified Java class name of
45 * the notification objects described by this class.</p>
46 *
47 * <p>The <CODE>getNotifTypes</CODE> method returns an array of
48 * strings containing the notification types that the MBean may
49 * emit. The notification type is a dot-notation string which
50 * describes what the emitted notification is about, not the Java
51 * class of the notification. A single generic notification class can
52 * be used to send notifications of several types. All of these types
53 * are returned in the string array result of the
54 * <CODE>getNotifTypes</CODE> method.
55 *
56 * @since 1.5
57 */
58 public class MBeanNotificationInfo extends MBeanFeatureInfo implements Cloneable {
59
60 /* Serial version */
61 static final long serialVersionUID = -3888371564530107064L;
62
63 private static final String[] NO_TYPES = new String[0];
64
65 static final MBeanNotificationInfo[] NO_NOTIFICATIONS =
66 new MBeanNotificationInfo[0];
67
68 /**
69 * @serial The different types of the notification.
70 */
71 private final String[] types;
72
73 /** @see MBeanInfo#arrayGettersSafe */
74 private final transient boolean arrayGettersSafe;
75
76 /**
77 * Constructs an <CODE>MBeanNotificationInfo</CODE> object.
78 *
79 * @param notifTypes The array of strings (in dot notation)
80 * containing the notification types that the MBean may emit.
81 * This may be null with the same effect as a zero-length array.
82 * @param name The fully qualified Java class name of the
83 * described notifications.
84 * @param description A human readable description of the data.
85 */
86 public MBeanNotificationInfo(String[] notifTypes,
87 String name,
88 String description) {
89 this(notifTypes, name, description, null);
90 }
91
92 /**
93 * Constructs an <CODE>MBeanNotificationInfo</CODE> object.
94 *
95 * @param notifTypes The array of strings (in dot notation)
96 * containing the notification types that the MBean may emit.
97 * This may be null with the same effect as a zero-length array.
98 * @param name The fully qualified Java class name of the
99 * described notifications.
100 * @param description A human readable description of the data.
101 * @param descriptor The descriptor for the notifications. This may be null
102 * which is equivalent to an empty descriptor.
103 *
104 * @since 1.6
105 */
106 public MBeanNotificationInfo(String[] notifTypes,
107 String name,
108 String description,
109 Descriptor descriptor) {
110 super(name, description, descriptor);
111
112 /* We do not validate the notifTypes, since the spec just says
113 they are dot-separated, not that they must look like Java
114 classes. E.g. the spec doesn't forbid "sun.prob.25" as a
115 notifType, though it doesn't explicitly allow it
116 either. */
117
118 if (notifTypes == null)
119 notifTypes = NO_TYPES;
120 this.types = notifTypes;
121 this.arrayGettersSafe =
122 MBeanInfo.arrayGettersSafe(this.getClass(),
123 MBeanNotificationInfo.class);
124 }
125
126
127 /**
128 * Returns a shallow clone of this instance.
129 * The clone is obtained by simply calling <tt>super.clone()</tt>,
130 * thus calling the default native shallow cloning mechanism
131 * implemented by <tt>Object.clone()</tt>.
132 * No deeper cloning of any internal field is made.
133 */
134 public Object clone () {
135 try {
136 return super.clone() ;
137 } catch (CloneNotSupportedException e) {
138 // should not happen as this class is cloneable
139 return null;
140 }
141 }
142
143
144 /**
145 * Returns the array of strings (in dot notation) containing the
146 * notification types that the MBean may emit.
147 *
148 * @return the array of strings. Changing the returned array has no
149 * effect on this MBeanNotificationInfo.
150 */
151 public String[] getNotifTypes() {
152 if (types.length == 0)
153 return NO_TYPES;
154 else
155 return types.clone();
156 }
157
158 private String[] fastGetNotifTypes() {
159 if (arrayGettersSafe)
160 return types;
161 else
162 return getNotifTypes();
163 }
164
165 public String toString() {
166 return
167 getClass().getName() + "[" +
168 "description=" + getDescription() + ", " +
169 "name=" + getName() + ", " +
170 "notifTypes=" + Arrays.asList(fastGetNotifTypes()) + ", " +
171 "descriptor=" + getDescriptor() +
172 "]";
173 }
174
175 /**
176 * Compare this MBeanNotificationInfo to another.
177 *
178 * @param o the object to compare to.
179 *
180 * @return true if and only if <code>o</code> is an MBeanNotificationInfo
181 * such that its {@link #getName()}, {@link #getDescription()},
182 * {@link #getDescriptor()},
183 * and {@link #getNotifTypes()} values are equal (not necessarily
184 * identical) to those of this MBeanNotificationInfo. Two
185 * notification type arrays are equal if their corresponding
186 * elements are equal. They are not equal if they have the same
187 * elements but in a different order.
188 */
189 public boolean equals(Object o) {
190 if (o == this)
191 return true;
192 if (!(o instanceof MBeanNotificationInfo))
193 return false;
194 MBeanNotificationInfo p = (MBeanNotificationInfo) o;
195 return (Objects.equals(p.getName(), getName()) &&
196 Objects.equals(p.getDescription(), getDescription()) &&
197 Objects.equals(p.getDescriptor(), getDescriptor()) &&
198 Arrays.equals(p.fastGetNotifTypes(), fastGetNotifTypes()));
199 }
200
201 public int hashCode() {
202 int hash = getName().hashCode();
203 for (int i = 0; i < types.length; i++)
204 hash ^= types[i].hashCode();
205 return hash;
206 }
207 }