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My first initial commit with all of mine experimental changes.

Dmitry Kabak (userdima committed 13 years ago

Commit d37b88d1 parent 3f5b46618352 files · +2598093 −-8690Browse files

Showing the changes to java/pkg/javax/management/DescriptorKey.java (1 of 18352 files). Show all

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java/pkg/javax/management/DescriptorKey.java+172−0
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1+/*
2+ * Copyright (c) 2005, 2008, 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.lang.annotation.*;
29+
30+/**
31+ * <p>Meta-annotation that describes how an annotation element relates
32+ * to a field in a {@link Descriptor}. This can be the Descriptor for
33+ * an MBean, or for an attribute, operation, or constructor in an
34+ * MBean, or for a parameter of an operation or constructor.</p>
35+ *
36+ * <p>Consider this annotation for example:</p>
37+ *
38+ * <pre>
39+ * &#64;Documented
40+ * &#64;Target(ElementType.METHOD)
41+ * &#64;Retention(RetentionPolicy.RUNTIME)
42+ * public &#64;interface Units {
43+ * <b>&#64;DescriptorKey("units")</b>
44+ * String value();
45+ * }
46+ * </pre>
47+ *
48+ * <p>and this use of the annotation:</p>
49+ *
50+ * <pre>
51+ * public interface CacheControlMBean {
52+ * <b>&#64;Units("bytes")</b>
53+ * public long getCacheSize();
54+ * }
55+ * </pre>
56+ *
57+ * <p>When a Standard MBean is made from the {@code CacheControlMBean},
58+ * the usual rules mean that it will have an attribute called
59+ * {@code CacheSize} of type {@code long}. The {@code @Units}
60+ * annotation, given the above definition, will ensure that the
61+ * {@link MBeanAttributeInfo} for this attribute will have a
62+ * {@code Descriptor} that has a field called {@code units} with
63+ * corresponding value {@code bytes}.</p>
64+ *
65+ * <p>Similarly, if the annotation looks like this:</p>
66+ *
67+ * <pre>
68+ * &#64;Documented
69+ * &#64;Target(ElementType.METHOD)
70+ * &#64;Retention(RetentionPolicy.RUNTIME)
71+ * public &#64;interface Units {
72+ * <b>&#64;DescriptorKey("units")</b>
73+ * String value();
74+ *
75+ * <b>&#64;DescriptorKey("descriptionResourceKey")</b>
76+ * String resourceKey() default "";
77+ *
78+ * <b>&#64;DescriptorKey("descriptionResourceBundleBaseName")</b>
79+ * String resourceBundleBaseName() default "";
80+ * }
81+ * </pre>
82+ *
83+ * <p>and it is used like this:</p>
84+ *
85+ * <pre>
86+ * public interface CacheControlMBean {
87+ * <b>&#64;Units("bytes",
88+ * resourceKey="bytes.key",
89+ * resourceBundleBaseName="com.example.foo.MBeanResources")</b>
90+ * public long getCacheSize();
91+ * }
92+ * </pre>
93+ *
94+ * <p>then the resulting {@code Descriptor} will contain the following
95+ * fields:</p>
96+ *
97+ * <table border="2">
98+ * <tr><th>Name</th><th>Value</th></tr>
99+ * <tr><td>units</td><td>"bytes"</td></tr>
100+ * <tr><td>descriptionResourceKey</td><td>"bytes.key"</td></tr>
101+ * <tr><td>descriptionResourceBundleBaseName</td>
102+ * <td>"com.example.foo.MBeanResources"</td></tr>
103+ * </table>
104+ *
105+ * <p>An annotation such as {@code @Units} can be applied to:</p>
106+ *
107+ * <ul>
108+ * <li>a Standard MBean or MXBean interface;
109+ * <li>a method in such an interface;
110+ * <li>a parameter of a method in a Standard MBean or MXBean interface
111+ * when that method is an operation (not a getter or setter for an attribute);
112+ * <li>a public constructor in the class that implements a Standard MBean
113+ * or MXBean;
114+ * <li>a parameter in such a constructor.
115+ * </ul>
116+ *
117+ * <p>Other uses of the annotation are ignored.</p>
118+ *
119+ * <p>Interface annotations are checked only on the exact interface
120+ * that defines the management interface of a Standard MBean or an
121+ * MXBean, not on its parent interfaces. Method annotations are
122+ * checked only in the most specific interface in which the method
123+ * appears; in other words, if a child interface overrides a method
124+ * from a parent interface, only {@code @DescriptorKey} annotations in
125+ * the method in the child interface are considered.
126+ *
127+ * <p>The Descriptor fields contributed in this way by different
128+ * annotations on the same program element must be consistent. That
129+ * is, two different annotations, or two members of the same
130+ * annotation, must not define a different value for the same
131+ * Descriptor field. Fields from annotations on a getter method must
132+ * also be consistent with fields from annotations on the
133+ * corresponding setter method.</p>
134+ *
135+ * <p>The Descriptor resulting from these annotations will be merged
136+ * with any Descriptor fields provided by the implementation, such as
137+ * the <a href="Descriptor.html#immutableInfo">{@code
138+ * immutableInfo}</a> field for an MBean. The fields from the annotations
139+ * must be consistent with these fields provided by the implementation.</p>
140+ *
141+ * <p>An annotation element to be converted into a descriptor field
142+ * can be of any type allowed by the Java language, except an annotation
143+ * or an array of annotations. The value of the field is derived from
144+ * the value of the annotation element as follows:</p>
145+ *
146+ * <table border="2">
147+ * <tr><th>Annotation element</th><th>Descriptor field</th></tr>
148+ * <tr><td>Primitive value ({@code 5}, {@code false}, etc)</td>
149+ * <td>Wrapped value ({@code Integer.valueOf(5)},
150+ * {@code Boolean.FALSE}, etc)</td></tr>
151+ * <tr><td>Class constant (e.g. {@code Thread.class})</td>
152+ * <td>Class name from {@link Class#getName()}
153+ * (e.g. {@code "java.lang.Thread"})</td></tr>
154+ * <tr><td>Enum constant (e.g. {@link ElementType#FIELD})</td>
155+ * <td>Constant name from {@link Enum#name()}
156+ * (e.g. {@code "FIELD"})</td></tr>
157+ * <tr><td>Array of class constants or enum constants</td>
158+ * <td>String array derived by applying these rules to each
159+ * element</td></tr>
160+ * <tr><td>Value of any other type<br>
161+ * ({@code String}, {@code String[]}, {@code int[]}, etc)</td>
162+ * <td>The same value</td></tr>
163+ * </table>
164+ *
165+ * @since 1.6
166+ */
167+@Documented
168+@Retention(RetentionPolicy.RUNTIME)
169+@Target(ElementType.METHOD)
170+public @interface DescriptorKey {
171+ String value();
172+}