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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* 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
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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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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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 8
*/
public interface DiagnosticCommandMBean extends DynamicMBean
{
}