With rapid development on Information Technology, a variety of academic theories had progressed continuously, by far Cloud Computing becomes most popular theory, for the benefit of Cloud Computing can be approached, Making the jobs of every layer be done completely(SaaS/PaaS/IaaS, every layer can get better performed by his layer's role), Making all of services be used anywhere (to service the global village without borders), Making all of resources fully be used(better use of existing resources), Making all of services easy to use (Every terminal can be used to purchase services). In this study, customer needs can be transferred to the conceptual information module and the module can be expressed with XML at SaaS layer. Then, the generated specification can be inserted to specification library by generally packaged API at PaaS layer. Subsequently, the other services can be used to access database by data field definitions of information module in specifications library. All services can use insert/update/query/delete XML patterns to access cloud database. In this study, for the motivation of building all of services by this easy way, we can use XML with intuitive and cross-platform features, as an intermediate medium for data transmission, while the specifications of customer needs pass to PaaS APIs by XML, then the specifications can be inserted into database through the IaaS management system by PaaS APIs, and IaaS management system can dispatch all of resources from different brand devices, all of specifications can be copied to the extra machines quickly, then the services can be launched immediately. At last, those benefits of Cloud Computing will be approached sufficiently by this study.
XML SAAS PAAS IAAS