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 MBeanServer by calling 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 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, CompositeData, and TabularData defined in OpenType. The mapping is specified below.

Platform MXBeans

A platform MXBean is a managed bean that conforms to the JMX Instrumentation Specification and only uses a set of basic data types described below. A JMX management application and the 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 open types and this allows interoperation across versions.

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 Integer, Long, Boolean, etc and String
• Enum classes
• Classes that define only getter methods and define a static from method with a CompositeData argument to convert from an input CompositeData to an instance of that class
• 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
• 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 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 CompositeData argument is mapped to CompositeData.
• Map<K,V> is mapped to TabularData whose row type is a 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.

The MBeanInfo for a platform MXBean describes the data types of the attributes and operations as primitive or open types mapped as specified above.

For example, the MemoryMXBean interface has the following getter and setter methods:

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

These attributes in the MBeanInfo of the MemoryMXBean have the following names and types:

Attribute Name	Type
HeapMemoryUsage	CompositeData representing MemoryUsage
Verbose	boolean

Implementation Note:

The mapping specified above could be done in the implementation of each platform MXBean. One good implementation choice is to implement a MXBean as a dynamic MBean.

MXBean Names

Each platform MXBean for a Java virtual machine has a unique ObjectName for registration in the platform MBeanServer. A Java virtual machine has a single instance of the following management interfaces:

Management Interface	ObjectName
ClassLoadingMXBean	java.lang:type=ClassLoading
MemoryMXBean	java.lang:type=Memory
ThreadMXBean	java.lang:type=Threading
RuntimeMXBean	java.lang:type=Runtime
OperatingSystemMXBean	java.lang:type=OperatingSystem

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

Management Interface	ObjectName
CompilationMXBean	java.lang:type=Compilation

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

Management Interface	ObjectName
GarbageCollectorMXBean	java.lang:type=GarbageCollector,name=collector's name
MemoryManagerMXBean	java.lang:type=MemoryManager,name=manager's name
MemoryPoolMXBean	java.lang:type=MemoryPool,name=pool's name

Since:

1.5

See Also:

JMX Specification., Ways to Access Management Metrics, LoggingMXBean

Field Summary

static String	CLASS_LOADING_MXBEAN_NAME String representation of the ObjectName for the ClassLoadingMXBean.
static String	COMPILATION_MXBEAN_NAME String representation of the ObjectName for the CompilationMXBean.
static String	GARBAGE_COLLECTOR_MXBEAN_DOMAIN_TYPE The domain name and the type key property in the ObjectName for a GarbageCollectorMXBean.
static String	MEMORY_MANAGER_MXBEAN_DOMAIN_TYPE The domain name and the type key property in the ObjectName for a MemoryManagerMXBean.
static String	MEMORY_MXBEAN_NAME String representation of the ObjectName for the MemoryMXBean.
static String	MEMORY_POOL_MXBEAN_DOMAIN_TYPE The domain name and the type key property in the ObjectName for a MemoryPoolMXBean.
static String	OPERATING_SYSTEM_MXBEAN_NAME String representation of the ObjectName for the OperatingSystemMXBean.
static String	RUNTIME_MXBEAN_NAME String representation of the ObjectName for the RuntimeMXBean.
static String	THREAD_MXBEAN_NAME String representation of the ObjectName for the ThreadMXBean.

Method Summary

static ClassLoadingMXBean	getClassLoadingMXBean() Returns the managed bean for the class loading system of the Java virtual machine.
static CompilationMXBean	getCompilationMXBean() Returns the managed bean for the compilation system of the Java virtual machine.
static List<GarbageCollectorMXBean>	getGarbageCollectorMXBeans() Returns a list of GarbageCollectorMXBean objects in the Java virtual machine.
static List<MemoryManagerMXBean>	getMemoryManagerMXBeans() Returns a list of MemoryManagerMXBean objects in the Java virtual machine.
static MemoryMXBean	getMemoryMXBean() Returns the managed bean for the memory system of the Java virtual machine.
static List<MemoryPoolMXBean>	getMemoryPoolMXBeans() Returns a list of MemoryPoolMXBean objects in the Java virtual machine.
static OperatingSystemMXBean	getOperatingSystemMXBean() Returns the managed bean for the operating system on which the Java virtual machine is running.
static MBeanServer	getPlatformMBeanServer() Returns the platform MBeanServer.
static RuntimeMXBean	getRuntimeMXBean() Returns the managed bean for the runtime system of the Java virtual machine.
static ThreadMXBean	getThreadMXBean() Returns the managed bean for the thread system of the Java virtual machine.
static <T> T	newPlatformMXBeanProxy(MBeanServerConnection connection, String mxbeanName, Class<T> mxbeanInterface) Returns a proxy for a platform MXBean interface of a given MXBean name that forwards its method calls through the given MBeanServerConnection.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

CLASS_LOADING_MXBEAN_NAME

public static final String CLASS_LOADING_MXBEAN_NAME

String representation of the ObjectName for the ClassLoadingMXBean.

See Also:

Constant Field Values

COMPILATION_MXBEAN_NAME

public static final String COMPILATION_MXBEAN_NAME

String representation of the ObjectName for the CompilationMXBean.

See Also:

Constant Field Values

MEMORY_MXBEAN_NAME

public static final String MEMORY_MXBEAN_NAME

String representation of the ObjectName for the MemoryMXBean.

See Also:

Constant Field Values

OPERATING_SYSTEM_MXBEAN_NAME

public static final String OPERATING_SYSTEM_MXBEAN_NAME

String representation of the ObjectName for the OperatingSystemMXBean.

See Also:

Constant Field Values

RUNTIME_MXBEAN_NAME

public static final String RUNTIME_MXBEAN_NAME

String representation of the ObjectName for the RuntimeMXBean.

See Also:

Constant Field Values

THREAD_MXBEAN_NAME

public static final String THREAD_MXBEAN_NAME

String representation of the ObjectName for the ThreadMXBean.

See Also:

Constant Field Values

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 GarbageCollectorMXBean. The unique ObjectName for a GarbageCollectorMXBean can be formed by appending this string with ",name=collector's name".

See Also:

Constant Field Values

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 MemoryManagerMXBean. The unique ObjectName for a MemoryManagerMXBean can be formed by appending this string with ",name=manager's name".

See Also:

Constant Field Values

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 MemoryPoolMXBean. The unique ObjectName for a MemoryPoolMXBean can be formed by appending this string with ,name=pool's name.

See Also:

Constant Field Values

Method Detail

getClassLoadingMXBean

public static ClassLoadingMXBean getClassLoadingMXBean()

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

Returns:

a ClassLoadingMXBean object for the Java virtual machine.

getMemoryMXBean

public static MemoryMXBean getMemoryMXBean()

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

Returns:

a MemoryMXBean 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 ThreadMXBean object for the Java virtual machine.

getRuntimeMXBean

public static RuntimeMXBean getRuntimeMXBean()

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

Returns:

a RuntimeMXBean 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 CompilationMXBean object for the Java virtual machine or null if the Java virtual machine has no compilation system.

getOperatingSystemMXBean

public static OperatingSystemMXBean getOperatingSystemMXBean()

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

Returns:

an OperatingSystemMXBean object for the Java virtual machine.

getMemoryPoolMXBeans

public static List<MemoryPoolMXBean> getMemoryPoolMXBeans()

Returns a list of 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.

getMemoryManagerMXBeans

public static List<MemoryManagerMXBean> getMemoryManagerMXBeans()

Returns a list of 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.

getGarbageCollectorMXBeans

public static List<GarbageCollectorMXBean> getGarbageCollectorMXBeans()

Returns a list of 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.

getPlatformMBeanServer

public static MBeanServer getPlatformMBeanServer()

Returns the platform MBeanServer. On the first call to this method, it first creates the platform MBeanServer by calling the 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 pools and 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 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.

Throws:

SecurityException - if there is a security manager and the caller does not have the permission required by MBeanServerFactory.createMBeanServer().

See Also:

MBeanServerFactory, MBeanServerFactory.createMBeanServer()

newPlatformMXBeanProxy

public static <T> T newPlatformMXBeanProxy(MBeanServerConnection connection,
                                           String mxbeanName,
                                           Class<T> 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:

Proxy.newProxyInstance(mxbeanInterface.getClassLoader(), new Class[] { mxbeanInterface }, handler)

where handler is an 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 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 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 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. MBeanServerInvocationHandler or its 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 ObjectName.

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

Throws:

IllegalArgumentException - if

• mxbeanName is not with a valid ObjectName format, or
• the named MXBean in the connection is not a MXBean provided by the platform, or
• the named MXBean is not registered in the MBeanServerConnection, or
• the named MXBean is not an instance of the given mxbeanInterface

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