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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.

The DiagnosticCommandMBean is registered to the 
platform MBeanServer as are other platform MBeans. 
The ObjectName for uniquely identifying the diagnostic MBean within an MBeanServer is: 
 com.sun.management:type=DiagnosticCommand 


This MBean is a DynamicMBean and also a NotificationEmitter. The DiagnosticCommandMBean is generated at runtime and is subject to modifications during the lifetime of the Java virtual machine. A diagnostic command is represented as an operation of the DiagnosticCommandMBean interface. Each diagnostic command has: 
    

  • the diagnostic command name which is the name being referenced in
    the HotSpot Virtual Machine
    • 

  • the MBean operation name which is the name generated for the diagnostic command operation invocation. The MBean operation name is implementation dependent
    • 


The recommended way to transform a diagnostic command name into a MBean
operation name is as follows:

    

  • All characters from the first one to the first dot are set to be
     lower-case characters
    • 

  • Every dot or underline character is removed and the following
  character is set to be an upper-case character
    • 

  • All other characters are copied without modification
    • 



The diagnostic command name is always provided with the meta-data on the operation in a field named dcmd.name (see below). 
A diagnostic command may or may not support options or arguments. All the operations return String and either take no parameter for operations that do not support any option or argument, or take a 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. 
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.

Like any operation of a dynamic MBean, each of these operations is described by MBeanOperationInfo instance. Here's the values returned by this object: 


The 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: 
description
  

    NameTypeDescription
  

  

    dcmd.nameString
    The original diagnostic command name (not the operation name)
  

  

    dcmd.descriptionString
    The diagnostic command description
  

  

    dcmd.helpString
    The full help message for this diagnostic command (same output as
         the one produced by the 'help' command)
  

  

    dcmd.vmImpactString
    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
  

  

    dcmd.enabledboolean
    True if the diagnostic command is enabled, false otherwise
  

  

    dcmd.permissionClassString
    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
  
  

  

    dcmd.permissionNameString
    The fist argument of the permission required to execute this
         diagnostic command or null if no permission is required
  

  

    dcmd.permissionActionString
    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
  

  

    dcmd.argumentsDescriptor
    A Descriptor instance containing the descriptions of options and
         arguments supported by the diagnostic command (see below)
  




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:

description
  

    NameTypeDescription
  

  

    dcmd.arg.nameString
    The name of the parameter
  

  

    dcmd.arg.typeString
    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.
         
  

  

    dcmd.arg.descriptionString
    The parameter description
  

  

    dcmd.arg.isMandatoryboolean
    True if the parameter is mandatory, false otherwise
  

  

    dcmd.arg.isOptionboolean
    True if the parameter is an option, false if it is an argument
  

  

    dcmd.arg.isMultipleboolean
    True if the parameter can be specified several times, false
         otherwise
  




When the set of diagnostic commands currently supported by the Java Virtual Machine is modified, the DiagnosticCommandMBean emits a Notification with a type of  "jmx.mbean.info.changed" and a userData that is the new MBeanInfo. 
Since:1.8
/**
 * 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}</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:
 *
 * <table class="striped"><caption style="display:none">description</caption>
 *   <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>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 class="striped"><caption style="display:none">description</caption>
 *   <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}/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
{

}