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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * 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.

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 * 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,

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 *

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package com.sun.management;

import java.lang.management.PlatformManagedObject;

import javax.management.DynamicMBean;

/**

 * Management interface for the diagnostic commands for the HotSpot Virtual Machine.

 *

 * <p>The {@code DiagnosticCommandMBean} is registered to the

 * {@linkplain java.lang.management.ManagementFactory#getPlatformMBeanServer

 * platform MBeanServer} as are other platform MBeans.

 *

 * <p>The {@link javax.management.ObjectName ObjectName} for uniquely identifying

 * the diagnostic MBean within an MBeanServer is:

 * <blockquote>

 *    {@code com.sun.management:type=DiagnosticCommand}

 * </blockquote>

 *

 * <p>This MBean is a {@link javax.management.DynamicMBean DynamicMBean}

 * and also a {@link javax.management.NotificationEmitter}.

 * The {@code DiagnosticCommandMBean} is generated at runtime and is subject to

 * modifications during the lifetime of the Java virtual machine.

 *

 * A <em>diagnostic command</em> is represented as an operation of

 * the {@code DiagnosticCommandMBean} interface. Each diagnostic command has:

 * <ul>

 * <li>the diagnostic command name which is the name being referenced in

 *     the HotSpot Virtual Machine</li>

 * <li>the MBean operation name which is the

 *     {@linkplain javax.management.MBeanOperationInfo#getName() name}

 *     generated for the diagnostic command operation invocation.

 *     The MBean operation name is implementation dependent</li>

 * </ul>

 *

 * The recommended way to transform a diagnostic command name into a MBean

 * operation name is as follows:

 * <ul>

 * <li>All characters from the first one to the first dot are set to be

 *      lower-case characters</li>

 * <li>Every dot or underline character is removed and the following

 *   character is set to be an upper-case character</li>

 * <li>All other characters are copied without modification</li>

 * </ul>

 *

 * <p>The diagnostic command name is always provided with the meta-data on the

 * operation in a field named {@code dcmd.name} (see below).

 *

 * <p>A diagnostic command may or may not support options or arguments.

 * All the operations return {@code String} and either take

 * no parameter for operations that do not support any option or argument,

 * or take a {@code String[]} parameter for operations that support at least

 * one option or argument.

 * Each option or argument must be stored in a single String.

 * Options or arguments split across several String instances are not supported.

 *

 * <p>The distinction between options and arguments: options are identified by

 * the option name while arguments are identified by their position in the

 * command line. Options and arguments are processed in the order of the array

 * passed to the invocation method.

 *

 * <p>Like any operation of a dynamic MBean, each of these operations is

 * described by {@link javax.management.MBeanOperationInfo MBeanOperationInfo}

 * instance. Here's the values returned by this object:

 * <ul>

 *  <li>{@link javax.management.MBeanOperationInfo#getName() getName()}

 *      returns the operation name generated from the diagnostic command name</li>

 *  <li>{@link javax.management.MBeanOperationInfo#getDescription() getDescription()}

 *      returns the diagnostic command description

 *      (the same as the one return in the 'help' command)</li>

 *  <li>{@link javax.management.MBeanOperationInfo#getImpact() getImpact()}

 *      returns <code>ACTION_INFO</code></li>

 *  <li>{@link javax.management.MBeanOperationInfo#getReturnType() getReturnType()}

 *      returns {@code java.lang.String}</li>

 *  <li>{@link javax.management.MBeanOperationInfo#getDescriptor() getDescriptor()}

 *      returns a Descriptor instance (see below)</li>

 * </ul>

 *

 * <p>The {@link javax.management.Descriptor Descriptor}

 * is a collection of fields containing additional

 * meta-data for a JMX element. A field is a name and an associated value.

 * The additional meta-data provided for an operation associated with a

 * diagnostic command are described in the table below:

 * <p>

 *

 * <table border="1" cellpadding="5">

 *   <tr>

 *     <th>Name</th><th>Type</th><th>Description</th>

 *   </tr>

 *   <tr>

 *     <td>dcmd.name</td><td>String</td>

 *     <td>The original diagnostic command name (not the operation name)</td>

 *   </tr>

 *   <tr>

 *     <td>dcmd.description</td><td>String</td>

 *     <td>The diagnostic command description</td>

 *   </tr>

 *   <tr>

 *     <td>dcmd.help</td><td>String</td>

 *     <td>The full help message for this diagnostic command (same output as

 *          the one produced by the 'help' command)</td>

 *   </tr>

 *   <tr>

 *     <td>dcmd.vmImpact</td><td>String</td>

 *     <td>The impact of the diagnostic command,

 *      this value is the same as the one printed in the 'impact'

 *      section of the help message of the diagnostic command, and it

 *      is different from the getImpact() of the MBeanOperationInfo</td>

 *   </tr>

 *   <tr>

 *     <td>dcmd.enabled</td><td>boolean</td>

 *     <td>True if the diagnostic command is enabled, false otherwise</td>

 *   </tr>

 *   <tr>

 *     <td>dcmd.permissionClass</td><td>String</td>

 *     <td>Some diagnostic command might require a specific permission to be

 *          executed, in addition to the MBeanPermission to invoke their

 *          associated MBean operation. This field returns the fully qualified

 *          name of the permission class or null if no permission is required

 *   </td>

 *   </tr>

 *   <tr>

 *     <td>dcmd.permissionName</td><td>String</td>

 *     <td>The fist argument of the permission required to execute this

 *          diagnostic command or null if no permission is required</td>

 *   </tr>

 *   <tr>

 *     <td>dcmd.permissionAction</td><td>String</td>

 *     <td>The second argument of the permission required to execute this

 *          diagnostic command or null if the permission constructor has only

 *          one argument (like the ManagementPermission) or if no permission

 *          is required</td>

 *   </tr>

 *   <tr>

 *     <td>dcmd.arguments</td><td>Descriptor</td>

 *     <td>A Descriptor instance containing the descriptions of options and

 *          arguments supported by the diagnostic command (see below)</td>

 *   </tr>

 * </table>

 * <p>

 *

 * <p>The description of parameters (options or arguments) of a diagnostic

 * command is provided within a Descriptor instance. In this Descriptor,

 * each field name is a parameter name, and each field value is itself

 * a Descriptor instance. The fields provided in this second Descriptor

 * instance are described in the table below:

 *

 * <table border="1" cellpadding="5">

 *   <tr>

 *     <th>Name</th><th>Type</th><th>Description</th>

 *   </tr>

 *   <tr>

 *     <td>dcmd.arg.name</td><td>String</td>

 *     <td>The name of the parameter</td>

 *   </tr>

 *   <tr>

 *     <td>dcmd.arg.type</td><td>String</td>

 *     <td>The type of the parameter. The returned String is the name of a type

 *          recognized by the diagnostic command parser. These types are not

 *          Java types and are implementation dependent.

 *          </td>

 *   </tr>

 *   <tr>

 *     <td>dcmd.arg.description</td><td>String</td>

 *     <td>The parameter description</td>

 *   </tr>

 *   <tr>

 *     <td>dcmd.arg.isMandatory</td><td>boolean</td>

 *     <td>True if the parameter is mandatory, false otherwise</td>

 *   </tr>

 *   <tr>

 *     <td>dcmd.arg.isOption</td><td>boolean</td>

 *     <td>True if the parameter is an option, false if it is an argument</td>

 *   </tr>

 *   <tr>

 *     <td>dcmd.arg.isMultiple</td><td>boolean</td>

 *     <td>True if the parameter can be specified several times, false

 *          otherwise</td>

 *   </tr>

 * </table>

 *

 * <p>When the set of diagnostic commands currently supported by the Java

 * Virtual Machine is modified, the {@code DiagnosticCommandMBean} emits

 * a {@link javax.management.Notification} with a

 * {@linkplain javax.management.Notification#getType() type} of

 * <a href="{@docRoot}/../../../../api/javax/management/MBeanInfo.html#info-changed">

 * {@code "jmx.mbean.info.changed"}</a> and a

 * {@linkplain javax.management.Notification#getUserData() userData} that

 * is the new {@code MBeanInfo}.

 *

 * @since 1.8

 */

public interface DiagnosticCommandMBean extends DynamicMBean

{

}