The Design And Implementation Of Instant Messaging System Based On Jabber

With the widespread of Internet and rapid development of network technology, the society is more and more dependent on the exchange of real-time information. Instant Messaging(IM) is a kind of new technology which is based on Internet, creates a new communication method for human being. Text chat is the basic function of IM, and some other functions, such as audio, video and SMS, can be integrated in IM. At present, the most popular applications about IM are Tencent's QQ, Microsoft's MSN and Yahoo's messenger. They have their own large amount users. Because they employ different communication protocols, it is very difficult to exchange information among these systems. Therefore, it results in isolated information systems. Recently, the open-source organization developed the new IM technology called Jabber. Its core protocol is XMPP(eXtensible Message Presence Protocol) based on XML(eXtensible Marked Language). The content of XMPP is open. Since it inherits the characteristic in XML environment, the IM application systems based on Jabber have strong extensibility.Based on Jabber protocol and Jabber systems, the principle and technology of Jabber IM system are analyzed in detail in this paper. By comparing and analyzing commonly used IM protocol and platforms, we design an IM system that can serve many different types of Jabber clients. Furthermore, we design and implement the common functions of IM server, such as login, registration, friend roster and sending message. Specially, due to the strong extensibility of Jabber protocol, we develop and implement a new function which is applied in mobile value-added service. In addition, the Jabber client based on J2ME is developed and implemented, which can be applied in the GPRS network. Finally, our system operates successfully. The simulation results indicate that the design of IM system is reasonable and stable, achieving the purposes of chat and value-added service.