Design And Implementation Of A Middleware For SAAS Application Development

Since the concept of SaaS was put forward, a large number of common management software products and services based on the SaaS mode have been developed both in China and abroad, the number of users are growing. Standing at the user’s point, there is a plenty of applications based on the SaaS mode, but at the developer’s point, it’s obviously inefficient if every development of a SaaS application have a copy of SaaS solution code in case of the current quantity of SaaS service grows day by day. Based on the above factors, the thesis is from a project of Beijing University of Posts and Telecommunications, Open Mobile Asset Management Platform, do research an open service middleware for SaaS application, it does not consider the business logic of the software, but focus on the implementation of the inherent characteristics of SaaS mode. Developers can quickly build and deploy a scalable, configurable and efficient SaaS application by calling open interfaces, resolves the transformation of SaaS mode in project, greatly reduce the development cycle and cost.The paper’s work mainly lists in the following aspects:first, analyses the maturity model and software architecture of SaaS mode, do research the key technology and application characteristics of SaaS model, design a SaaS middleware framework with a third party developers needs in terms of system construction, presents the corresponding technical implementation plan on the system multi-layer architecture, design a middleware for SaaS application development, from the point of view of application system construction is designed SaaS middleware software architecture. And then summarizes the key problems that the SaaS middleware need to solve, like the data isolation and filtering, data extension, function can be configured and page can be configured, puts forward corresponding technical implementation plan from the user customization layer, application service layer and data service layer, to help the third party developers to realize SaaS solutions, implements a middleware called by the third party developers. Finally, based on the idea of component, finished the design and packaging of interface using SCA, and released for Web Service, achieve the loose coupling of each submodule maximumly, hide the implementation details of service.The main contribution of the paper is:according to the tenant data structure block, using a Shared database/isolation data structure and a Shared database/share data structure scheme for developers, and put forward a scheme to realize the user access mechanism under isolation data framework using the combination of Schema switching and storage process, and use the Flyweight Pattern mode to avoid the problem of too much data connection pool lead to low performance in case of large number of users. According to the data extension module, the paper proposes a kind of expansion plan based public table using XML, fulfil the unlimitedly expanding demand of user’s data, avoid the destruction of the original table structure and too much connection inquires in data retrieval. According to the function can be extended module, the paper proposes a kind of Aspect Oriented function verification scheme, making developers just need to do some configuration to complete the tenants function validation without modify the original code. In order to verify the feasibility of the middleware, this paper will apply middleware to the Open Mobile Asset Management Platform, prove the usability of interface.