Once again O'Reilly have given us another excellent Java book.
The Java Management Extensions (JMX) is the Java standard for management of applications. In real terms this means providing an interface to your java applications so that they can be modified and monitored in a standard way.
If you have used JBoss or Tomcat 4.1.x you may have noticed that many of the functions of these applications are handled through managed beans (MBeans). Reading this book has been very beneficial to my understanding of how this all operates.
The book covers the different types of MBeans, what they are, what needs to be done to make a bean managed and how the MBean server operates. The book's examples are all executed against version 1.0 of the reference implementation (which I believe came out between the end of 1999 and mid 2000).
The book gives very clear examples of how to create managed beans using each of the increasingly complicated methods. Many books suffer from lack of relevant sample code, this book is not one of those. If there is something that you want to do with a managed bean then chances are there is an example somewhere in the book that shows how it is done.
The book is easy to read but occasionally repetitive. However it is hard not to be at least a little repetitive when you are implementing the same code again and again only differing in the manner in which a management interface is exposed.
I would recommend this book to any Java programmer wanting to know how to implement managed beans. Once again O'Reilly have given us another excellent Java book.