New Article: Finite State Machine Supporting Concurrent States

We've just published Jeff Lowery's new article on developing finite state machines in Java. Jeff's article demonstrates how Java enums and EnumSets can be applied to define and validate states and state transitions. Finite state machines (FSMs) are finding increasing application today. This type of modeling reminds me of my education in physics and chemistry, where a set of distinct potential states exist, and the physical universe toggles among those possibilities. The notion of "in between" doesn't really exist in such a universe. Yet, when you think of electrons jumping between energy states, or quantum mechanics -- you realize that the basis of much of our understanding of the physical universe relies on conceiving the micro-universe as being a kind of finite state machine. Hence, the growing recognition of the validity of applying states and state transitions to a wide variety of practical problems does indeed make a lot of sense. The macro-scale universe reflects the finite state machine nature that appears to model the micro-scale universe well. Jeff's article starts out with describing how a typical application can be understood as consisting of a set of states and transitions between those states: A typical application will go through multiple states during a runtime session, e.g., RUNNING -> PAUSED -> RESTARTED, or (in the case of a data entry form) ENTER -> VALIDATE -> SAVE. The state tr...

Date: September, 09 2009
Url: http://www.java.net/blog/editor/archive/2009/09/09/new-article-finite-state-machine-supporting-concurrent-states

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