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* <tr> * <tr> * </table> * * <p>The {@code @DescriptorFields} annotation can be applied to:

* * <ul> * <li>a Standard MBean or MXBean interface; * <li>a method in such an interface; * <li>a parameter of a method in a Standard MBean or MXBean interface * when that method is an operation (not a getter or setter for an attribute); * <li>a public constructor in the class that implements a Standard MBean * or MXBean; * <li>a parameter in such a constructor. * </ul> * * <p>Other uses of the annotation will either fail to compile or be * ignored.</p> * * <p>Interface annotations are checked only on the exact interface * that defines the management interface of a Standard MBean or an * MXBean, not on its parent interfaces. Method annotations are * checked only in the most specific interface in which the method * appears; in other words, if a child interface overrides a method * from a parent interface, only {@code @DescriptorFields} annotations in * the method in the child interface are considered. * * <p>The Descriptor fields contributed in this way must be consistent * with each other and with any fields contributed by * DescriptorKey annotations. That is, two * different annotations, or two members of the same annotation, must * not define a different value for the same Descriptor field. Fields * from annotations on a getter method must also be consistent with * fields from annotations on the corresponding setter method.</p> * * <p>The Descriptor resulting from these annotations will be merged * with any Descriptor fields provided by the implementation, such as * the <a href="Descriptor.html#immutableInfo">{@code * immutableInfo}</a> field for an MBean. The fields from the annotations * must be consistent with these fields provided by the implementation.</p> * * <h4>{@literal @DescriptorFields and @DescriptorKey} * * <p>The DescriptorKey annotation provides * another way to use annotations to define Descriptor fields. * <code>@DescriptorKey requires more work but is also more * robust, because there is less risk of mistakes such as misspelling * the name of the field or giving an invalid value. * <code>@DescriptorFields is more convenient but includes * those risks. <code>@DescriptorFields is more * appropriate for occasional use, but for a Descriptor field that you * add in many places, you should consider a purpose-built annotation * using <code>@DescriptorKey. * * @since 1.7 */ @Documented @Inherited // for @MBean and @MXBean classes @Target({ElementType.CONSTRUCTOR, ElementType.METHOD, ElementType.FIELD, ElementType.PARAMETER, ElementType.TYPE}) @Retention(RetentionPolicy.RUNTIME) public @interface DescriptorFields { /** * <p>The descriptor fields. Each element of the string looks like * {@code "name=value"}.</p> */ public String[] value(); }

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Java example source code file (DescriptorFields.java)

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Java - Java tags/keywords

annotation, descriptorfields, documented, inherited, mbean, mxbean, string, target

The DescriptorFields.java Java example source code

/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */



package com.sun.org.glassfish.gmbal;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/** This is taken directly from JDK 7 in order to support this feature in
 * JDK 5.
 *
 * <p>Annotation that adds fields to a Descriptor.  This can be the
 * Descriptor for an MBean, or for an attribute, operation, or constructor
 * in an MBean, or for a parameter of an operation or constructor.</p>
 *
 * <p>Consider this Standard MBean interface, for example:

 *
 * <pre>
 * public interface CacheControlMBean {
 *     <b>@DescriptorFields("units=bytes")
 *     public long getCacheSize();
 * }
 * </pre>
 *
 * <p>When a Standard MBean is made using this interface, the usual rules
 * mean that it will have an attribute called {@code CacheSize} of type
 * {@code long}.  The {@code DescriptorFields} annotation will ensure
 * that the MBeanAttributeInfo for this attribute will have a
 * {@code Descriptor} that has a field called {@code units} with
 * corresponding value {@code bytes}.</p>
 *
 * <p>Similarly, if the interface looks like this:

 *
 * <pre>
 * public interface CacheControlMBean {
 *     <b>@DescriptorFields({"units=bytes", "since=1.5"})
 *     public long getCacheSize();
 * }
 * </pre>
 *
 * <p>then the resulting {@code Descriptor} will contain the following
 * fields:</p>
 *
 * <table border="2">
 * <tr>
NameValue
units"bytes"
since"1.5"
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