关键词: Java管理扩展框架, 观察者模式, 分布式工作流引擎

Abstract: To deal with application requirements on distributed workflow engine from enterprises and government, a design and implementation of Self-Managed Distributed Workflow Engine based on Java Management Extensions (JMX ) and Observer Pattern was presented. Communications between the central engine and the executive engines were realized by the Observer Pattern. The asynchronous characteristics were implemented by making use of JMX Notification Model and JMX Timer Service. The central engine acted as the object, and all the executive engines acted as the observers to observe the state changes of the central engine. Adopting the Round-Robin algorithm, the scheduler assigned an executive engine for each activity. The executive engine registered with the central engine during the start time, and logout from the central engine during the close time therefore the self-managed workflow system was implemented. The encapsulation of workflow relevant data by the Workflow Namespace object and the good transaction provided by the Enterprise Java Bean (EJB) container ensured the reliability of the workflow system.

Key words: Java management extensions, observer pattern, distributed workflow engine