JMX - Mbean (Managed Bean|Manageable resource)

> Procedural Languages > Java > Java - Java Management eXtensions (JMX)

1 - About

A managed bean (MBean) is a Java object that represents a JMX manageable resource in a distributed environment, such as:

  • an application,
  • a service,
  • a component
  • or a device.

An MBean is a named managed object representing a resource.

Developers of applications and devices are free to choose the granularity of objects that are instrumented as MBeans. An MBean might represent:

  • the smallest object in an application,
  • or the entire application.

Application components designed with their management interface in mind can typically be written as MBeans. MBeans can also be used as wrappers for legacy code without a management interface or as proxies for code with a legacy management interface.

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3 - Type

The JMX specification defines five types of MBean:

The simplest types of MBean are standard MBeans and MXBeans.

4 - Management

4.1 - Addressing

A management application uses the object name to identify the object on which it is to perform a management operation.

4.2 - Interface

The management interface of an MBean consists of:

  • A set of readable or writable attributes, or both.
  • A set of invokable operations.
  • A self-description.
  • Typed notifications that can be emitted by the MBean
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4.3 - Object Reference

The Java class of a standard MBean exposes the resource to be managed directly through:

  • its attributes: (such as the cache system is off). Attributes are internal entities that are exposed through getter and setter methods.
  • and operations: Operations are the other methods of the class that are available to managers. All these methods are defined statically.

5 - Documentation / Reference