Object Oriented Method to Implement the Hierarchical and Concurrent States in UML State Chart Diagrams

The event driven systems can be modeled and implemented using UML state chart diagrams. Code generation tools are used in the software development for making software system designs and for automatically generating skeletal source code from the system designs. Many research works concentrate on the automatic code generation from the state diagrams. Unfortunately the existing Object oriented languages do not support the direct implementation of state diagrams. We cannot find a one to one mapping between elements in the state chart diagram and the Object oriented programming constructs. The two main components of state diagram that cannot be effectively implemented in object oriented way is state hierarchy and concurrency. In this paper, we present an implementation pattern for the state diagram which includes both hierarchical and concurrent states. The state transitions of parallel states are delegated to the composite state class. We implemented the proposed approach and compared with similar tools and the result is promising.