/*

 * Copyright (c) 2003, 2015, 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

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package java.lang.management;

import java.io.FilePermission;

import java.io.IOException;

import javax.management.DynamicMBean;

import javax.management.MBeanServer;

import javax.management.MBeanServerConnection;

import javax.management.MBeanServerFactory;

import javax.management.MBeanServerPermission;

import javax.management.NotificationEmitter;

import javax.management.ObjectName;

import javax.management.InstanceNotFoundException;

import javax.management.MalformedObjectNameException;

import javax.management.StandardEmitterMBean;

import javax.management.StandardMBean;

import java.util.Collections;

import java.util.List;

import java.util.Set;

import java.util.Map;

import java.security.AccessController;

import java.security.Permission;

import java.security.PrivilegedAction;

import java.security.PrivilegedActionException;

import java.security.PrivilegedExceptionAction;

import java.util.ArrayList;

import java.util.Collection;

import java.util.Optional;

import java.util.ServiceLoader;

import java.util.function.Function;

import java.util.stream.Collectors;

import static java.util.stream.Collectors.toMap;

import java.util.stream.Stream;

import javax.management.JMX;

import sun.management.Util;

import sun.management.spi.PlatformMBeanProvider;

import sun.management.spi.PlatformMBeanProvider.PlatformComponent;

/**

 * The {@code ManagementFactory} class is a factory class for getting

 * managed beans for the Java platform.

 * This class consists of static methods each of which returns

 * one or more <i>platform MXBeans</i> representing

 * the management interface of a component of the Java virtual

 * machine.

 *

 * <h3><a name="MXBean">Platform MXBeans</a></h3>

 * <p>

 * A platform MXBean is a <i>managed bean</i> that

 * conforms to the <a href="../../../javax/management/package-summary.html">JMX</a>

 * Instrumentation Specification and only uses a set of basic data types.

 * A JMX management application and the {@linkplain

 * #getPlatformMBeanServer platform MBeanServer}

 * can interoperate without requiring classes for MXBean specific

 * data types.

 * The data types being transmitted between the JMX connector

 * server and the connector client are

 * {@linkplain javax.management.openmbean.OpenType open types}

 * and this allows interoperation across versions.

 * See <a href="../../../javax/management/MXBean.html#MXBean-spec">

 * the specification of MXBeans</a> for details.

 *

 * <a name="MXBeanNames"></a>

 * <p>Each platform MXBean is a {@link PlatformManagedObject}

 * and it has a unique

 * {@link javax.management.ObjectName ObjectName} for

 * registration in the platform {@code MBeanServer} as returned by

 * by the {@link PlatformManagedObject#getObjectName getObjectName}

 * method.

 *

 * <p>

 * An application can access a platform MXBean in the following ways:

 * <h4>1. Direct access to an MXBean interface</h4>

 * <blockquote>

 * <ul>

 *     <li>Get an MXBean instance by calling the

 *         {@link #getPlatformMXBean(Class) getPlatformMXBean} or

 *         {@link #getPlatformMXBeans(Class) getPlatformMXBeans} method

 *         and access the MXBean locally in the running

 *         virtual machine.

 *         </li>

 *     <li>Construct an MXBean proxy instance that forwards the

 *         method calls to a given {@link MBeanServer MBeanServer} by calling

 *         the {@link #getPlatformMXBean(MBeanServerConnection, Class)} or

 *         {@link #getPlatformMXBeans(MBeanServerConnection, Class)} method.

 *         The {@link #newPlatformMXBeanProxy newPlatformMXBeanProxy} method

 *         can also be used to construct an MXBean proxy instance of

 *         a given {@code ObjectName}.

 *         A proxy is typically constructed to remotely access

 *         an MXBean of another running virtual machine.

 *         </li>

 * </ul>

 * <h4>2. Indirect access to an MXBean interface via MBeanServer</h4>

 * <ul>

 *     <li>Go through the platform {@code MBeanServer} to access MXBeans

 *         locally or a specific <tt>MBeanServerConnection</tt> to access

 *         MXBeans remotely.

 *         The attributes and operations of an MXBean use only

 *         <em>JMX open types</em> which include basic data types,

 *         {@link javax.management.openmbean.CompositeData CompositeData},

 *         and {@link javax.management.openmbean.TabularData TabularData}

 *         defined in

 *         {@link javax.management.openmbean.OpenType OpenType}.

 *         The mapping is specified in

 *         the {@linkplain javax.management.MXBean MXBean} specification

 *         for details.

 *        </li>

 * </ul>

 * </blockquote>

 *

 * <p>

 * The {@link #getPlatformManagementInterfaces getPlatformManagementInterfaces}

 * method returns all management interfaces supported in the Java virtual machine

 * including the standard management interfaces listed in the tables

 * below as well as the management interfaces extended by the JDK implementation.

 * <p>

 * A Java virtual machine has a single instance of the following management

 * interfaces:

 *

 * <blockquote>

 * <table border summary="The list of Management Interfaces and their single instances">

 * <tr>

 * <th>Management Interface</th>

 * <th>ObjectName</th>

 * </tr>

 * <tr>

 * <td> {@link ClassLoadingMXBean} </td>

 * <td> {@link #CLASS_LOADING_MXBEAN_NAME

 *             java.lang:type=ClassLoading}</td>

 * </tr>

 * <tr>

 * <td> {@link MemoryMXBean} </td>

 * <td> {@link #MEMORY_MXBEAN_NAME

 *             java.lang:type=Memory}</td>

 * </tr>

 * <tr>

 * <td> {@link ThreadMXBean} </td>

 * <td> {@link #THREAD_MXBEAN_NAME

 *             java.lang:type=Threading}</td>

 * </tr>

 * <tr>

 * <td> {@link RuntimeMXBean} </td>

 * <td> {@link #RUNTIME_MXBEAN_NAME

 *             java.lang:type=Runtime}</td>

 * </tr>

 * <tr>

 * <td> {@link OperatingSystemMXBean} </td>

 * <td> {@link #OPERATING_SYSTEM_MXBEAN_NAME

 *             java.lang:type=OperatingSystem}</td>

 * </tr>

 * <tr>

 * <td> {@link PlatformLoggingMXBean} </td>

 * <td> {@link java.util.logging.LogManager#LOGGING_MXBEAN_NAME

 *             java.util.logging:type=Logging}</td>

 * </tr>

 * </table>

 * </blockquote>

 *

 * <p>

 * A Java virtual machine has zero or a single instance of

 * the following management interfaces.

 *

 * <blockquote>

 * <table border summary="The list of Management Interfaces and their single instances">

 * <tr>

 * <th>Management Interface</th>

 * <th>ObjectName</th>

 * </tr>

 * <tr>

 * <td> {@link CompilationMXBean} </td>

 * <td> {@link #COMPILATION_MXBEAN_NAME

 *             java.lang:type=Compilation}</td>

 * </tr>

 * </table>

 * </blockquote>

 *

 * <p>

 * A Java virtual machine may have one or more instances of the following

 * management interfaces.

 * <blockquote>

 * <table border summary="The list of Management Interfaces and their single instances">

 * <tr>

 * <th>Management Interface</th>

 * <th>ObjectName</th>

 * </tr>

 * <tr>

 * <td> {@link GarbageCollectorMXBean} </td>

 * <td> {@link #GARBAGE_COLLECTOR_MXBEAN_DOMAIN_TYPE

 *             java.lang:type=GarbageCollector}<tt>,name=</tt><i>collector's name</i></td>

 * </tr>

 * <tr>

 * <td> {@link MemoryManagerMXBean} </td>

 * <td> {@link #MEMORY_MANAGER_MXBEAN_DOMAIN_TYPE

 *             java.lang:type=MemoryManager}<tt>,name=</tt><i>manager's name</i></td>

 * </tr>

 * <tr>

 * <td> {@link MemoryPoolMXBean} </td>

 * <td> {@link #MEMORY_POOL_MXBEAN_DOMAIN_TYPE

 *             java.lang:type=MemoryPool}<tt>,name=</tt><i>pool's name</i></td>

 * </tr>

 * <tr>

 * <td> {@link BufferPoolMXBean} </td>

 * <td> {@code java.nio:type=BufferPool,name=}<i>pool name</i></td>

 * </tr>

 * </table>

 * </blockquote>

 *

 * @see <a href="../../../javax/management/package-summary.html">

 *      JMX Specification</a>

 * @see <a href="package-summary.html#examples">

 *      Ways to Access Management Metrics</a>

 * @see javax.management.MXBean

 *

 * @author  Mandy Chung

 * @since   1.5

 */

public class ManagementFactory {

    // A class with only static fields and methods.

    private ManagementFactory() {};

    /**

     * String representation of the

     * <tt>ObjectName</tt> for the {@link ClassLoadingMXBean}.

     */

    public final static String CLASS_LOADING_MXBEAN_NAME =

        "java.lang:type=ClassLoading";

    /**

     * String representation of the

     * <tt>ObjectName</tt> for the {@link CompilationMXBean}.

     */

    public final static String COMPILATION_MXBEAN_NAME =

        "java.lang:type=Compilation";

    /**

     * String representation of the

     * <tt>ObjectName</tt> for the {@link MemoryMXBean}.

     */

    public final static String MEMORY_MXBEAN_NAME =

        "java.lang:type=Memory";

    /**

     * String representation of the

     * <tt>ObjectName</tt> for the {@link OperatingSystemMXBean}.

     */

    public final static String OPERATING_SYSTEM_MXBEAN_NAME =

        "java.lang:type=OperatingSystem";

    /**

     * String representation of the

     * <tt>ObjectName</tt> for the {@link RuntimeMXBean}.

     */

    public final static String RUNTIME_MXBEAN_NAME =

        "java.lang:type=Runtime";

    /**

     * String representation of the

     * <tt>ObjectName</tt> for the {@link ThreadMXBean}.

     */

    public final static String THREAD_MXBEAN_NAME =

        "java.lang:type=Threading";

    /**

     * The domain name and the type key property in

     * the <tt>ObjectName</tt> for a {@link GarbageCollectorMXBean}.

     * The unique <tt>ObjectName</tt> for a <tt>GarbageCollectorMXBean</tt>

     * can be formed by appending this string with

     * "<tt>,name=</tt><i>collector's name</i>".

     */

    public final static String GARBAGE_COLLECTOR_MXBEAN_DOMAIN_TYPE =

        "java.lang:type=GarbageCollector";

    /**

     * The domain name and the type key property in

     * the <tt>ObjectName</tt> for a {@link MemoryManagerMXBean}.

     * The unique <tt>ObjectName</tt> for a <tt>MemoryManagerMXBean</tt>

     * can be formed by appending this string with

     * "<tt>,name=</tt><i>manager's name</i>".

     */

    public final static String MEMORY_MANAGER_MXBEAN_DOMAIN_TYPE=

        "java.lang:type=MemoryManager";

    /**

     * The domain name and the type key property in

     * the <tt>ObjectName</tt> for a {@link MemoryPoolMXBean}.

     * The unique <tt>ObjectName</tt> for a <tt>MemoryPoolMXBean</tt>

     * can be formed by appending this string with

     * <tt>,name=</tt><i>pool's name</i>.

     */

    public final static String MEMORY_POOL_MXBEAN_DOMAIN_TYPE=

        "java.lang:type=MemoryPool";

    /**

     * Returns the managed bean for the class loading system of

     * the Java virtual machine.

     *

     * @return a {@link ClassLoadingMXBean} object for

     * the Java virtual machine.

     */

    public static ClassLoadingMXBean getClassLoadingMXBean() {

        return getPlatformMXBean(ClassLoadingMXBean.class);

    }

    /**

     * Returns the managed bean for the memory system of

     * the Java virtual machine.

     *

     * @return a {@link MemoryMXBean} object for the Java virtual machine.

     */

    public static MemoryMXBean getMemoryMXBean() {

        return getPlatformMXBean(MemoryMXBean.class);

    }

    /**

     * Returns the managed bean for the thread system of

     * the Java virtual machine.

     *

     * @return a {@link ThreadMXBean} object for the Java virtual machine.

     */

    public static ThreadMXBean getThreadMXBean() {

        return getPlatformMXBean(ThreadMXBean.class);

    }

    /**

     * Returns the managed bean for the runtime system of

     * the Java virtual machine.

     *

     * @return a {@link RuntimeMXBean} object for the Java virtual machine.

     */

    public static RuntimeMXBean getRuntimeMXBean() {

        return getPlatformMXBean(RuntimeMXBean.class);

    }

    /**

     * Returns the managed bean for the compilation system of

     * the Java virtual machine.  This method returns <tt>null</tt>

     * if the Java virtual machine has no compilation system.

     *

     * @return a {@link CompilationMXBean} object for the Java virtual

     *   machine or <tt>null</tt> if the Java virtual machine has

     *   no compilation system.

     */

    public static CompilationMXBean getCompilationMXBean() {

        return getPlatformMXBean(CompilationMXBean.class);

    }

    /**

     * Returns the managed bean for the operating system on which

     * the Java virtual machine is running.

     *

     * @return an {@link OperatingSystemMXBean} object for

     * the Java virtual machine.

     */

    public static OperatingSystemMXBean getOperatingSystemMXBean() {

        return getPlatformMXBean(OperatingSystemMXBean.class);

    }

    /**

     * Returns a list of {@link MemoryPoolMXBean} objects in the

     * Java virtual machine.

     * The Java virtual machine can have one or more memory pools.

     * It may add or remove memory pools during execution.

     *

     * @return a list of <tt>MemoryPoolMXBean</tt> objects.

     *

     */

    public static List<MemoryPoolMXBean> getMemoryPoolMXBeans() {

        return getPlatformMXBeans(MemoryPoolMXBean.class);

    }

    /**

     * Returns a list of {@link MemoryManagerMXBean} objects

     * in the Java virtual machine.

     * The Java virtual machine can have one or more memory managers.

     * It may add or remove memory managers during execution.

     *

     * @return a list of <tt>MemoryManagerMXBean</tt> objects.

     *

     */

    public static List<MemoryManagerMXBean> getMemoryManagerMXBeans() {

        return getPlatformMXBeans(MemoryManagerMXBean.class);

    }

    /**

     * Returns a list of {@link GarbageCollectorMXBean} objects

     * in the Java virtual machine.

     * The Java virtual machine may have one or more

     * <tt>GarbageCollectorMXBean</tt> objects.

     * It may add or remove <tt>GarbageCollectorMXBean</tt>

     * during execution.

     *

     * @return a list of <tt>GarbageCollectorMXBean</tt> objects.

     *

     */

    public static List<GarbageCollectorMXBean> getGarbageCollectorMXBeans() {

        return getPlatformMXBeans(GarbageCollectorMXBean.class);

    }

    private static MBeanServer platformMBeanServer;

    /**

     * Returns the platform {@link javax.management.MBeanServer MBeanServer}.

     * On the first call to this method, it first creates the platform

     * {@code MBeanServer} by calling the

     * {@link javax.management.MBeanServerFactory#createMBeanServer

     * MBeanServerFactory.createMBeanServer}

     * method and registers each platform MXBean in this platform

     * {@code MBeanServer} with its

     * {@link PlatformManagedObject#getObjectName ObjectName}.

     * This method, in subsequent calls, will simply return the

     * initially created platform {@code MBeanServer}.

     * <p>

     * MXBeans that get created and destroyed dynamically, for example,

     * memory {@link MemoryPoolMXBean pools} and

     * {@link MemoryManagerMXBean managers},

     * will automatically be registered and deregistered into the platform

     * {@code MBeanServer}.

     * <p>

     * If the system property {@code javax.management.builder.initial}

     * is set, the platform {@code MBeanServer} creation will be done

     * by the specified {@link javax.management.MBeanServerBuilder}.

     * <p>

     * It is recommended that this platform MBeanServer also be used

     * to register other application managed beans

     * besides the platform MXBeans.

     * This will allow all MBeans to be published through the same

     * {@code MBeanServer} and hence allow for easier network publishing

     * and discovery.

     * Name conflicts with the platform MXBeans should be avoided.

     *

     * @return the platform {@code MBeanServer}; the platform

     *         MXBeans are registered into the platform {@code MBeanServer}

     *         at the first time this method is called.

     *

     * @exception SecurityException if there is a security manager

     * and the caller does not have the permission required by

     * {@link javax.management.MBeanServerFactory#createMBeanServer}.

     *

     * @see javax.management.MBeanServerFactory

     * @see javax.management.MBeanServerFactory#createMBeanServer

     */

    public static synchronized MBeanServer getPlatformMBeanServer() {

        SecurityManager sm = System.getSecurityManager();

        if (sm != null) {

            Permission perm = new MBeanServerPermission("createMBeanServer");

            sm.checkPermission(perm);

        }

        if (platformMBeanServer == null) {

            platformMBeanServer = MBeanServerFactory.createMBeanServer();

            platformComponents()

                    .stream()

                    .filter(PlatformComponent::shouldRegister)

                    .flatMap(pc -> pc.nameToMBeanMap().entrySet().stream())

                    .forEach(entry -> addMXBean(platformMBeanServer, entry.getKey(), entry.getValue()));

        }

        return platformMBeanServer;

    }

    /**

     * Returns a proxy for a platform MXBean interface of a

     * given <a href="#MXBeanNames">MXBean name</a>

     * that forwards its method calls through the given

     * <tt>MBeanServerConnection</tt>.

     *

     * <p>This method is equivalent to:

     * <blockquote>

     * {@link java.lang.reflect.Proxy#newProxyInstance

     *        Proxy.newProxyInstance}<tt>(mxbeanInterface.getClassLoader(),

     *        new Class[] { mxbeanInterface }, handler)</tt>

     * </blockquote>

     *

     * where <tt>handler</tt> is an {@link java.lang.reflect.InvocationHandler

     * InvocationHandler} to which method invocations to the MXBean interface

     * are dispatched. This <tt>handler</tt> converts an input parameter

     * from an MXBean data type to its mapped open type before forwarding

     * to the <tt>MBeanServer</tt> and converts a return value from

     * an MXBean method call through the <tt>MBeanServer</tt>

     * from an open type to the corresponding return type declared in

     * the MXBean interface.

     *

     * <p>

     * If the MXBean is a notification emitter (i.e.,

     * it implements

     * {@link javax.management.NotificationEmitter NotificationEmitter}),

     * both the <tt>mxbeanInterface</tt> and <tt>NotificationEmitter</tt>

     * will be implemented by this proxy.

     *

     * <p>