The Design And Implementation Of Cross-Platform Instant Message Library Based On XMPP

With the rapid development of network technology, instant messaging has already become an important way for people to exchange information, and instant messaging software grows up as the same, the most typical of those are QQ, MSN and GTALK, they all have different advantages an disadvantages, and since they use the different instant messaging protocol, they can not communicate with each other. The apperence of XMPP protocol has changed the embarrassment of instant messaging software that can not communicate with each other.The XMPP which is based on XML was developed by an open source organization. It is also based on distributed network architecture and module system architecture, and it has the advantages like open, secure, simple and extensible, so for developing an instant messaging software, the protocol get a lot of advantages than others. This paper does some research on instant messaging system based on XMPP protocol to build a cross-platform instant messaging library.In this paper, the main researches include the theory of XMPP protocol, the architecture of instant messaging based on XMPP protocol and the relationship between the components in this library. For the interation among the modules, we created a light-weighted framework which is cross-platform and similar with COM. In this paper we designed and implemented it in detail.For the most important part of the instant message system is the presence, this paper will do a detailed research on this one. And the research content include the diversity of user presence for an enterprise-class instant message system; for the different login type, how to handle the presence; and when received a prensence, how to handle it if it is a self presence or a buddy presence.The End-to-End encryption theory in this paper can solve the safeness trouble in XMPP systems effectively. This theory is that using RSA algorithm to exchange AES Session key which is used to encrypt or decrypt the privacy messages through the XMPP stanza. E2E encryption can protect the privacy messages from being decrypted in XMPP Server.