java.lang.management
class ManagementFactory

java.lang.Object java.lang.management.ManagementFactory

public class ManagementFactory
extends Object

The 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 platform MXBean(s) representing the management interface of a component of the Java virtual machine.

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

• Direct access to an MXBean interface
  1. Get the MXBean instance through the static factory method and access the MXBean locally of the running virtual machine.
  2. Construct an MXBean proxy instance that forwards the method calls to a given {@link MBeanServer MBeanServer} by calling {@link #newPlatformMXBeanProxy newPlatfromMXBeanProxy}. A proxy is typically constructed to remotely access an MXBean of another running virtual machine.
• Indirect access to an MXBean interface via MBeanServer
  1. Go through the {@link #getPlatformMBeanServer platform MBeanServer} to access MXBeans locally or a specific MBeanServerConnection to access MXBeans remotely. The attributes and operations of an MXBean use only JMX open types 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 below.

Platform MXBeans

The platform MXBean interfaces use only the following data types:

• Primitive types such as int, long, boolean, etc
• Wrapper classes for primitive types such as {@link java.lang.Integer Integer}, {@link java.lang.Long Long}, {@link java.lang.Boolean Boolean}, etc and {@link java.lang.String String}
• {@link java.lang.Enum Enum} classes
• Classes that define only getter methods and define a static from method with a {@link javax.management.openmbean.CompositeData CompositeData} argument to convert from an input CompositeData to an instance of that class
• {@link java.util.List List<E>} where E is a primitive type, a wrapper class, an enum class, or a class supporting conversion from a CompositeData to its class
• {@link java.util.Map Map<K,V>} where K and V are a primitive type, a wrapper class, an enum class, or a class supporting conversion from a CompositeData to its class

When an attribute or operation of a platform MXBean is accessed via an MBeanServer, the data types are mapped as follows:

• A primitive type or a wrapper class is mapped to the same type.
• An {@link Enum} is mapped to String whose value is the name of the enum constant.
• A class that defines only getter methods and a static from method with a {@link javax.management.openmbean.CompositeData CompositeData} argument is mapped to {@link javax.management.openmbean.CompositeData CompositeData}.
• Map<K,V> is mapped to {@link javax.management.openmbean.TabularData TabularData} whose row type is a {@link javax.management.openmbean.CompositeType CompositeType} with two items whose names are "key" and "value" and the item types are the corresponding mapped type of K and V respectively and the "key" is the index.
• List<E> is mapped to an array with the mapped type of E as the element type.
• An array of element type E is mapped to an array of the same dimenions with the mapped type of E as the element type.

For example, the {@link MemoryMXBean} interface has the following getter and setter methods:

 public MemoryUsage getHeapMemoryUsage();
 public boolean isVerbose();
 public void setVerbose(boolean value);
 

Attribute Name	Type
HeapMemoryUsage	{@link MemoryUsage#from CompositeData representing MemoryUsage}
Verbose	boolean

MXBean Names

Management Interface	ObjectName
{@link ClassLoadingMXBean}	{@link #CLASS_LOADING_MXBEAN_NAME java.lang:type=ClassLoading}
{@link MemoryMXBean}	{@link #MEMORY_MXBEAN_NAME java.lang:type=Memory}
{@link ThreadMXBean}	{@link #THREAD_MXBEAN_NAME java.lang:type=Threading}
{@link RuntimeMXBean}	{@link #RUNTIME_MXBEAN_NAME java.lang:type=Runtime}
{@link OperatingSystemMXBean}	{@link #OPERATING_SYSTEM_MXBEAN_NAME java.lang:type=OperatingSystem}

A Java virtual machine has zero or a single instance of the following management interfaces.

Management Interface	ObjectName
{@link CompilationMXBean}	{@link #COMPILATION_MXBEAN_NAME java.lang:type=Compilation}

A Java virtual machine may have one or more instances of the following management interfaces.

Management Interface	ObjectName
{@link GarbageCollectorMXBean}	{@link #GARBAGE_COLLECTOR_MXBEAN_DOMAIN_TYPE java.lang:type=GarbageCollector},name=collector's name
{@link MemoryManagerMXBean}	{@link #MEMORY_MANAGER_MXBEAN_DOMAIN_TYPE java.lang:type=MemoryManager},name=manager's name
{@link MemoryPoolMXBean}	{@link #MEMORY_POOL_MXBEAN_DOMAIN_TYPE java.lang:type=MemoryPool},name=pool's name

CLASS_LOADING_MXBEAN_NAME

public static final String CLASS_LOADING_MXBEAN_NAME

String representation of the ObjectName for the {@link ClassLoadingMXBean}.

COMPILATION_MXBEAN_NAME

public static final String COMPILATION_MXBEAN_NAME

String representation of the ObjectName for the {@link CompilationMXBean}.

GARBAGE_COLLECTOR_MXBEAN_DOMAIN_TYPE

public static final String GARBAGE_COLLECTOR_MXBEAN_DOMAIN_TYPE

The domain name and the type key property in the ObjectName for a {@link GarbageCollectorMXBean}. The unique ObjectName for a GarbageCollectorMXBean can be formed by appending this string with ",name=collector's name".

MEMORY_MANAGER_MXBEAN_DOMAIN_TYPE

public static final String MEMORY_MANAGER_MXBEAN_DOMAIN_TYPE

The domain name and the type key property in the ObjectName for a {@link MemoryManagerMXBean}. The unique ObjectName for a MemoryManagerMXBean can be formed by appending this string with ",name=manager's name".

MEMORY_MXBEAN_NAME

public static final String MEMORY_MXBEAN_NAME

String representation of the ObjectName for the {@link MemoryMXBean}.

MEMORY_POOL_MXBEAN_DOMAIN_TYPE

public static final String MEMORY_POOL_MXBEAN_DOMAIN_TYPE

The domain name and the type key property in the ObjectName for a {@link MemoryPoolMXBean}. The unique ObjectName for a MemoryPoolMXBean can be formed by appending this string with ,name=pool's name.

OPERATING_SYSTEM_MXBEAN_NAME

public static final String OPERATING_SYSTEM_MXBEAN_NAME

String representation of the ObjectName for the {@link OperatingSystemMXBean}.

RUNTIME_MXBEAN_NAME

public static final String RUNTIME_MXBEAN_NAME

String representation of the ObjectName for the {@link RuntimeMXBean}.

THREAD_MXBEAN_NAME

public static final String THREAD_MXBEAN_NAME

String representation of the ObjectName for the {@link ThreadMXBean}.

getClassLoadingMXBean

public static ClassLoadingMXBean getClassLoadingMXBean()

Returns the managed bean for the class loading system of the Java virtual machine.

Returns:

a {@link ClassLoadingMXBean} object for the Java virtual machine.

getCompilationMXBean

public static CompilationMXBean getCompilationMXBean()

Returns the managed bean for the compilation system of the Java virtual machine. This method returns null if the Java virtual machine has no compilation system.

Returns:

a {@link CompilationMXBean} object for the Java virtual machine or null if the Java virtual machine has no compilation system.

getGarbageCollectorMXBeans

public static List getGarbageCollectorMXBeans()

Returns a list of {@link GarbageCollectorMXBean} objects in the Java virtual machine. The Java virtual machine may have one or more GarbageCollectorMXBean objects. It may add or remove GarbageCollectorMXBean during execution.

Returns:

a list of GarbageCollectorMXBean objects.

getMemoryManagerMXBeans

public static List getMemoryManagerMXBeans()

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.

Returns:

a list of MemoryManagerMXBean objects.

getMemoryMXBean

public static MemoryMXBean getMemoryMXBean()

Returns the managed bean for the memory system of the Java virtual machine.

Returns:

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

getMemoryPoolMXBeans

public static List getMemoryPoolMXBeans()

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.

Returns:

a list of MemoryPoolMXBean objects.

getOperatingSystemMXBean

public static OperatingSystemMXBean getOperatingSystemMXBean()

Returns the managed bean for the operating system on which the Java virtual machine is running.

Returns:

an {@link OperatingSystemMXBean} object for the Java virtual machine.

getPlatformMBeanServer

public static synchronized MBeanServer getPlatformMBeanServer()

Returns the platform {@link javax.management.MBeanServer MBeanServer}. On the first call to this method, it first creates the platform MBeanServer by calling the {@link javax.management.MBeanServerFactory#createMBeanServer MBeanServerFactory.createMBeanServer} method and registers the platform MXBeans in this platform MBeanServer using the MXBean names defined in the class description. This method, in subsequent calls, will simply return the initially created platform MBeanServer.

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 MBeanServer.

If the system property javax.management.builder.initial is set, the platform MBeanServer creation will be done by the specified {@link javax.management.MBeanServerBuilder}.

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 MBeanServer and hence allow for easier network publishing and discovery. Name conflicts with the platform MXBeans should be avoided.

Returns:

the platform MBeanServer; the platform MXBeans are registered into the platform MBeanServer at the first time this method is called.

getRuntimeMXBean

public static RuntimeMXBean getRuntimeMXBean()

Returns the managed bean for the runtime system of the Java virtual machine.

Returns:

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

getThreadMXBean

public static ThreadMXBean getThreadMXBean()

Returns the managed bean for the thread system of the Java virtual machine.

Returns:

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

newPlatformMXBeanProxy

public static Object newPlatformMXBeanProxy(MBeanServerConnection connection,
                                            String mxbeanName,
                                            Class mxbeanInterface)
                                     throws IOException

Returns a proxy for a platform MXBean interface of a given MXBean name that forwards its method calls through the given MBeanServerConnection.

This method is equivalent to:

{@link java.lang.reflect.Proxy#newProxyInstance Proxy.newProxyInstance}(mxbeanInterface.getClassLoader(), new Class[] { mxbeanInterface }, handler)

where handler is an {@link java.lang.reflect.InvocationHandler InvocationHandler} to which method invocations to the MXBean interface are dispatched. This handler converts an input parameter from an MXBean data type to its mapped open type before forwarding to the MBeanServer and converts a return value from an MXBean method call through the MBeanServer from an open type to the corresponding return type declared in the MXBean interface.

If the MXBean is a notification emitter (i.e., it implements {@link javax.management.NotificationEmitter NotificationEmitter}), both the mxbeanInterface and NotificationEmitter will be implemented by this proxy.

Notes:

1. Using an MXBean proxy is a convenience remote access to a platform MXBean of a running virtual machine. All method calls to the MXBean proxy are forwarded to an MBeanServerConnection where {@link java.io.IOException IOException} may be thrown when the communication problem occurs with the connector server. An application remotely accesses the platform MXBeans using proxy should prepare to catch IOException as if accessing with the MBeanServerConnector interface.
2. When a client application is designed to remotely access MXBeans for a running virtual machine whose version is different than the version on which the application is running, it should prepare to catch {@link java.io.InvalidObjectException InvalidObjectException} which is thrown when an MXBean proxy receives a name of an enum constant which is missing in the enum class loaded in the client application.
3. {@link javax.management.MBeanServerInvocationHandler MBeanServerInvocationHandler} or its {@link javax.management.MBeanServerInvocationHandler#newProxyInstance newProxyInstance} method cannot be used to create a proxy for a platform MXBean. The proxy object created by MBeanServerInvocationHandler does not handle the properties of the platform MXBeans described in the class specification.

Parameters:

connection - the MBeanServerConnection to forward to.

mxbeanName - the name of a platform MXBean within connection to forward to. mxbeanName must be in the format of {@link ObjectName ObjectName}.

mxbeanInterface - the MXBean interface to be implemented by the proxy.

Throws:

IOException - if a communication problem occurred when accessing the MBeanServerConnection.