Design And Realization Of Wireless Messaging System Based On Ajax

With the rapid development of information technology, it is imperative that phones and other mobile devices would be linked with the Internet. The mobilization of traditional Web applications has become an important issue. As wireless e-mail system has a wide application, it has been concerned and researched all over the world.Firstly, the paper summarizes the basic principles of the mail system, analyses some main protocols of mail system such as SMTP, POP3, IMAP and MIME. Then, it introduces GPRS wireless data transmission technology and some popular wireless data services such as SMS, EMS, MMS and Java applications. For wireless e-mail system, the paper have discussed the evolution of the system models, compared the PULL with PUSH technologies. Also, For the mobile client development technology, it respectively analyses and discusses the advantages and disadvantages of the three major solutions WAP, BREW and J2ME, for further research, the paper analyses the integrated solutions of J2ME-J2EE, J2ME-BREW, and points out their deficiencies.On the basis of the analysis, it introduces a new Web development technology Ajax and describes its characteristics, principle and components, Ajax shows great superiority. Further, based on the new technologies such as JSON and SVG which expanded and complemented Ajax, OpenAjax Alliance which tremendously supported the industry, and communities and organizations' tireless efforts and outstanding achievements of Ajax, the paper demonstrates the bright future of Ajax and Mobile Ajax.The restriction of Mobile devices and wireless network has brought new challenges to Mobile Ajax. The paper meticulously analyzes the present situation of Mobile Ajax, cites the numerous difficulties and limitations from a technical perspective, clarifies their identities, and proves the significance of the Mobile Ajax. Finally, concerned that Mobile Ajax has nothing to do with the server and design principle of wireless e-mail system, taking J2EE as server-side platform, using JavaMail APIs as standard mail service, the paper proposes a solution for the wireless e-mail system based on Ajax and gives the system model.The paper clearly proposes the key points of design as well as related principles, and analyses model its model and functions. Combining with MVC model and Ajax's feature, and reusing the MVC design pattern in JavaScript, the system is designed. The Ajax-based wireless e-mail system uses JavaMail APIs and JSP, forms a three-tier B/S structure, separates the data, business logic and viewing distinctly. Some key technologies encountered in the design, such as Race Condition and domain synchronizing, are analyzed and resolved.Finally, the paper summarizes the databases, Java's core classes, user interface, JavaScript function, JSP, and other major implementation processes, and also presents the codes. Especially, the paper implements some advanced technologies such as confusion and compression of JavaScript, YFT, and data pre-fetch.