Java Management Extensions

Chapter 5. Open MBeans

So far, we have looked at three ways to instrument resources to be manageable. Now we will look at a way to instrument resources so that they are the most open to management applications. In this chapter, we will discuss how to instrument resources whose attributes are more complex than the fundamental types and whose operations take complex parameters. The key to this more open means of instrumentation lies in the set of data types defined by the JMX specification called open MBeans. By using open MBeans, we can instrument application resources of any type and make them available to any agent or management application that does not have access to the bytecode for either the resource, attribute, or operation parameter. The agent or management application can even be a non-Java program!

We will first look at the various open MBean types. Those types include the fundamental types, such as int, long, and char, as well as new types, such as structural and tabular data. All of the open MBean types are classes that derive from a single open MBean type, OpenType.

Next, we will examine the various open MBean metadata classes that allow us to instrument our resources as open MBeans. At the time of this writing, open MBeans are newly finalized (they were not part of the JMX 1.0 specification), so some of the information in this chapter may be subject to change.

Open MBean Types

The open MBean types are at the heart of what makes open MBeans “open.” The JMX RI defines ...