---
-- -- Management Interface
- Description
- -{@link java.lang.management.ClassLoadingMXBean} -Class loading system of the Java virtual machine. -- -{@link java.lang.management.CompilationMXBean} -Compilation system of the Java virtual machine. -- -{@link java.lang.management.MemoryMXBean} -Memory system of the Java virtual machine. -- -{@link java.lang.management.ThreadMXBean} -Threads system of the Java virtual machine. -- -{@link java.lang.management.RuntimeMXBean} -Runtime system of the Java virtual machine. -- -{@link java.lang.management.OperatingSystemMXBean} -Operating system on which the Java virtual machine is running. -- -{@link java.lang.management.GarbageCollectorMXBean} -Garbage collector in the Java virtual machine. -- -{@link java.lang.management.MemoryManagerMXBean} -Memory manager in the Java virtual machine. -- -{@link java.lang.management.MemoryPoolMXBean} -Memory pool in the Java virtual machine. -
-A platform MXBean is a managed bean that defines the management -interface for one component for the platform and is specified in the - -ManagementFactory class. -
An application can monitor the instrumentation of the -Java virtual machine and manage certain characteristics in -the following ways: -
+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 {@link java.lang.management.PlatformManagedObject} +with a unique +{@linkplain java.lang.management.PlatformManagedObject#getObjectName name}. +
The {@link java.lang.management.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. @@ -137,50 +53,98 @@ {@link java.lang.management.ManagementFactory#getPlatformMBeanServer getPlatformMBeanServer} method. On the first call to this method, it creates the platform MBeanServer and registers all platform MXBeans -including platform MXBeans defined in other packages such as -{@link java.util.logging.LoggingMXBean}. -Each platform MXBean is registered with a unique name defined in the -{@link java.lang.management.ManagementFactory ManagementFactory} class -for constructing {@link javax.management.ObjectName ObjectName}. +including {@linkplain java.lang.management.PlatformManagedObject +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 -{@link javax.management.openmbean.OpenType open types} and +{@linkplain javax.management.openmbean.OpenType 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. -
A data type used by the MXBean interfaces are mapped to -an open type when being accessed via MBeanServer interface. -The data type mapping is specified in the -{@link java.lang.management.ManagementFactory ManagementFactory} class. -
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 ++
+
- Get an MXBean instance locally in the running Java virtual machine:
+
RuntimeMXBean mxbean = ManagementFactory.getRuntimeMXBean(); // Get the standard attribute "VmVendor" String vendor = mxbean.getVmVendor(); ++Or by calling the + {@link java.lang.management.ManagementFactory#getPlatformMXBean(Class) + getPlatformMXBean} or + {@link java.lang.management.ManagementFactory#getPlatformMXBeans(Class) + 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 = + {@link java.lang.management.ManagementFactory#getPlatformMXBean(MBeanServerConnection, Class) + 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 = + {@link java.lang.management.ManagementFactory#newPlatformMXBeanProxy + ManagementFactory.newPlatformMXBeanProxy}(mbs, + ManagementFactory.RUNTIME_MXBEAN_NAME, + RuntimeMXBean.class); ++ + ++2. Indirect access to an MXBean interface via MBeanServer
+
+
-- Go through the + {@link java.lang.management.ManagementFactory#getPlatformMBeanServer + platform MBeanServer} to access MXBeans locally or + a specific {@code 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}.
++
MBeanServerConnection mbs; // Connect to a running JVM (or itself) and get MBeanServerConnection @@ -198,36 +162,19 @@ // and MBeanServer.getAttribute method ... } ++
-- 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.newPlatformMXBeanProxy(mbs, - ManagementFactory.RUNTIME_MXBEAN_NAME, - RuntimeMXBean.class); - // Get standard attribute "VmVendor" - String vendor = proxy.getVmVendor(); -
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 MBeans with the platform extension. +return the MXBeans with the platform extension.
It is recommended to name the platform-specific attributes with @@ -240,26 +187,30 @@ 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 a platform-specific -attribute from Sun's implementation of the RuntimeMXBean. +
Below is an example showing how to access an attribute +from the platform extension:
-1) Direct access to the Sun-specific MXBean interface -
- com.sun.management.RuntimeMXBean mxbean = - (com.sun.management.RuntimeMXBean) ManagementFactory.getRuntimeMXBean(); +1) Direct access to the Oracle-specific MXBean interface +++ List<com.sun.management.GarbageCollectorMXBean> mxbeans = + ManagementFactory.getPlatformMXBeans(com.sun.management.GarbageCollectorMXBean.class); - // Get the standard attribute "VmVendor" - String vendor = mxbean.getVmVendor(); + for (com.sun.management.GarbageCollectorMXBean gc : mxbeans) { + // Get the standard attribute "CollectionCount" + String count = mxbean.getCollectionCount(); - // Get the platform-specific attribute "Bar" - BarType bar = mxbean.getBar(); - + // Get the platform-specific attribute "LastGcInfo" + GcInfo gcinfo = gc.getLastGcInfo(); + ... + }-2) Access the Sun-specific MXBean interface via MBeanServer +2) Access the Oracle-specific MXBean interface via MBeanServer + through proxy
MBeanServerConnection mbs; @@ -268,24 +219,18 @@ // 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"); + List<com.sun.management.GarbageCollectorMXBean> mxbeans = + ManagementFactory.getPlatformMXBeans(mbs, com.sun.management.GarbageCollectorMXBean.class); - // Check if this MXBean contains Sun's extension - if (mbs.isInstanceOf(oname, "com.sun.management.RuntimeMXBean")) { - // Get platform-specific attribute "Bar" - BarType bar = (String) mbs.getAttribute(oname, "Bar"); - } - } catch (....) { - // Catch the exceptions thrown by ObjectName constructor - // and MBeanServer methods + 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