The Research And Application Of Event Model Based Domain-driven Design On Web Development

In order to resolve the problems exist in the traditional software developmentmethod of Web applications,which is focus on database modeling,Domain DrivenDesign and Event Sourcing,"DDD+ES" for short, as a novel software developmentmethod, has been widely adopted in enterprises’ Web applications, and becomes theuniversally recognized effective solution to the problem of software complexity. Thisapproach based on “DDD+ES" ensures the maintainability, extensibility andreusability of the system, and has clear advantages especially in dealing withcomplex business logics, Therefore,"DDD+ES" has gradually being applied in thedevelopment of large enterprise-class Web applications systems. However, probelemsalso exist in the existing "DDD+ES" approach, the aggregate root will be upgradedor downgraded when system needs remodeling, the historical events of some objectscan not be obtained, while certain entities have no events to load, thus leads to thestate missing of some objects.This paper is based on previous research on the theory and practical experienceof domain driven design and event sourcing, it analyzes the causes of these problemsin depth, then presents a new solution, it propoeses to abandon the aggregationconception in domain driven design, make all the objects return to equal instead, andlet the entity complete the corresponding duties and business rule judgment in its ownspace, furthere more, this paper designs a event-model based DDD framework whichis suitable for Web applications.This paper applies the proposed event driven architecture to a case of Webapplication development. The practice has proved that the framework can solve theproblems the above "DDD+ES" mothed encountered in the reconstruction ofexisting systems, and can be better adapted to changes in software requirements.Meanwhile, after performance tests, compared to traditional “DDD+ES” systems,this event-model based system exhibits superior performance in response time andthroughput. This event-model based DDD framework is a feasible solution to practicethe domain driven development ideas. Finally, this paper summarizes the work thathave done and points out that still deserves further study and improvement.