Java Management Extensions

The Sample Producer/Consumer Application

In the remainder of this chapter, we will build and run a sample application that demonstrates each MBean instrumentation approach. The sections that follow look at the design of the application, where to obtain the source code, how to actually build and run the application, and how to monitor the application via a web browser.

Design

In this section, we will take a look at how the sample application is designed, so that you can better understand what is going on when you see it run. First, we will look at the pattern that is fundamental to the application’s design. Then we will see how the pattern is implemented and what classes constitute the source code for the application.

The design pattern used in the application is a monitor. A monitor is a construct that coordinates activity between multiple threads in the system. In this pattern, the monitor coordinates activities between two categories of threads: producer threads and consumer threads. As you might imagine, a producer thread provides something that the consumer uses. That “something” is generically defined as a unit of work. This can be physically realized as anything relevant to a problem that is solved by this pattern.

For example, the unit of work might be an email message that is sent to the email system (the monitor) by the producer (an email client) and removed by the consumer (some agent on the incoming email server side). The producer might perform additional processing ...