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/*
* 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:</p>
*
* <pre>
* public interface CacheControlMBean {
* <b>@DescriptorFields("units=bytes")</b>
* 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:</p>
*
* <pre>
* public interface CacheControlMBean {
* <b>@DescriptorFields({"units=bytes", "since=1.5"})</b>
* public long getCacheSize();
* }
* </pre>
*
* <p>then the resulting {@code Descriptor} will contain the following
* fields:</p>
*
* <table border="2">
* <tr><th>Name</th><th>Value</th></tr>
* <tr><td>units</td><td>"bytes"</td></tr>
* <tr><td>since</td><td>"1.5"</td></tr>
* </table>
*
* <p>The {@code @DescriptorFields} annotation can be applied to:</p>
*
* <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}</h4>
*
* <p>The DescriptorKey annotation provides
* another way to use annotations to define Descriptor fields.
* <code>@DescriptorKey</code> 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</code> is more convenient but includes
* those risks. <code>@DescriptorFields</code> 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</code>.
*
* @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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