See: Description
Interface | Description |
---|---|
BufferPoolMXBean | |
ClassLoadingMXBean |
The management interface for the class loading system of
the Java virtual machine.
|
CompilationMXBean |
The management interface for the compilation system of
the Java virtual machine.
|
GarbageCollectorMXBean |
The management interface for the garbage collection of
the Java virtual machine.
|
MemoryManagerMXBean |
The management interface for a memory manager.
|
MemoryMXBean |
The management interface for the memory system of
the Java virtual machine.
|
MemoryPoolMXBean |
The management interface for a memory pool.
|
OperatingSystemMXBean |
The management interface for the operating system on which
the Java virtual machine is running.
|
PlatformLoggingMXBean |
The management interface for the logging facility.
|
PlatformManagedObject |
A platform managed object is a JMX MXBean
for monitoring and managing a component in the Java platform.
|
RuntimeMXBean |
The management interface for the runtime system of
the Java virtual machine.
|
ThreadMXBean |
The management interface for the thread system of
the Java virtual machine.
|
Class | Description |
---|---|
LockInfo |
Information about a lock.
|
ManagementFactory |
The
ManagementFactory class is a factory class for getting
managed beans for the Java platform. |
ManagementPermission |
The permission which the SecurityManager will check when code
that is running with a SecurityManager calls methods defined
in the management interface for the Java platform.
|
MemoryNotificationInfo |
The information about a memory notification.
|
MemoryUsage |
A MemoryUsage object represents a snapshot of memory usage.
|
MonitorInfo |
Information about an object monitor lock.
|
ThreadInfo |
Thread information.
|
Enum | Description |
---|---|
MemoryType |
Types of
memory pools . |
A platform MXBean is a managed bean that
conforms to the JMX
Instrumentation Specification and only uses a set of basic data types.
Each platform MXBean is a PlatformManagedObject
with a unique
name.
The ManagementFactory
class is the management
factory class for the Java platform. This class provides a set of
static factory methods to obtain the MXBeans for the Java platform
to allow an application to access the MXBeans directly.
A platform MBeanServer can be accessed with the
getPlatformMBeanServer
method. On the first call to this method,
it creates the platform MBeanServer and registers all platform MXBeans
including platform MXBeans.
Each platform MXBean is registered with a unique name defined in
the specification of the management interface.
This is a single MBeanServer that can be shared by different managed
components running within the same Java virtual machine.
A management application and a platform MBeanServer of a running virtual machine can interoperate without requiring classes used by the platform MXBean interfaces. The data types being transmitted between the JMX connector server and the connector client are JMX open types and this allows interoperation across versions. A data type used by the MXBean interfaces are mapped to an open type when being accessed via MBeanServer interface. See the MXBean specification for details.
An application can monitor the instrumentation of the Java virtual machine and the runtime in the following ways:
1. Direct access to an MXBean interface
RuntimeMXBean mxbean = ManagementFactory.getRuntimeMXBean(); // Get the standard attribute "VmVendor" String vendor = mxbean.getVmVendor();
Or by calling the
getPlatformMXBean
or
getPlatformMXBeans
method:
RuntimeMXBean mxbean = ManagementFactory.getPlatformMXBean(RuntimeMXBean.class); // Get the standard attribute "VmVendor" String vendor = mxbean.getVmVendor();
MBeanServerConnection mbs;
// Connect to a running JVM (or itself) and get MBeanServerConnection
// that has the JVM MBeans registered in it
...
// Get a MBean proxy for RuntimeMXBean interface
RuntimeMXBean proxy =
ManagementFactory.getPlatformMXBean
(mbs,
RuntimeMXBean.class);
// Get standard attribute "VmVendor"
String vendor = proxy.getVmVendor();
A proxy is typically used to access an MXBean in a remote Java virtual machine. An alternative way to create an MXBean proxy is:
RuntimeMXBean proxy =
ManagementFactory.newPlatformMXBeanProxy
(mbs,
ManagementFactory.RUNTIME_MXBEAN_NAME,
RuntimeMXBean.class);
2. Indirect access to an MXBean interface via MBeanServer
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
.
MBeanServerConnection mbs; // Connect to a running JVM (or itself) and get MBeanServerConnection // that has the JVM MXBeans registered in it ... try { // Assuming the RuntimeMXBean has been registered in mbs ObjectName oname = new ObjectName(ManagementFactory.RUNTIME_MXBEAN_NAME); // Get standard attribute "VmVendor" String vendor = (String) mbs.getAttribute(oname, "VmVendor"); } catch (....) { // Catch the exceptions thrown by ObjectName constructor // and MBeanServer.getAttribute method ... }
A Java virtual machine implementation may add its platform extension to the management interface by defining platform-dependent interfaces that extend the standard management interfaces to include platform-specific metrics and management operations. The static factory methods in the ManagementFactory class will return the MXBeans with the platform extension.
It is recommended to name the platform-specific attributes with a vendor-specific prefix such as the vendor's name to avoid collisions of the attribute name between the future extension to the standard management interface and the platform extension. If the future extension to the standard management interface defines a new attribute for a management interface and the attribute name is happened to be same as some vendor-specific attribute's name, the applications accessing that vendor-specific attribute would have to be modified to cope with versioning and compatibility issues.
Below is an example showing how to access an attribute from the platform extension:
1) Direct access to the Oracle-specific MXBean interface
List<com.sun.management.GarbageCollectorMXBean> mxbeans = ManagementFactory.getPlatformMXBeans(com.sun.management.GarbageCollectorMXBean.class); for (com.sun.management.GarbageCollectorMXBean gc : mxbeans) { // Get the standard attribute "CollectionCount" String count = mxbean.getCollectionCount(); // Get the platform-specific attribute "LastGcInfo" GcInfo gcinfo = gc.getLastGcInfo(); ... }
2) Access the Oracle-specific MXBean interface via MBeanServer through proxy
MBeanServerConnection mbs; // Connect to a running JVM (or itself) and get MBeanServerConnection // that has the JVM MXBeans registered in it ... List<com.sun.management.GarbageCollectorMXBean> mxbeans = ManagementFactory.getPlatformMXBeans(mbs, com.sun.management.GarbageCollectorMXBean.class); for (com.sun.management.GarbageCollectorMXBean gc : mxbeans) { // Get the standard attribute "CollectionCount" String count = mxbean.getCollectionCount(); // Get the platform-specific attribute "LastGcInfo" GcInfo gcinfo = gc.getLastGcInfo(); ... }
Unless otherwise noted, passing a null argument to a constructor
or method in any class or interface in this package will cause a NullPointerException
to be thrown.
The java.lang.management API is thread-safe.
Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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