Research And Implementation On Instant Messaging System Based On Android

In recent years, the instant messaging system based on mobile devices develops rapidly, and has been gradually integrated into humans life. On the one hand, more and more applications need to integrate the functions of instant messaging, which benifits to providing users the instant messaging function independent on the third-party. On the other hand, considering the information security, medium-sized enterprises cannot utilize the public instant messaging resources such as QQ and Weixin. In addition, current mainstream instant messaging systems commonly adopt private protocols, which makes it hard for small and medium-sized business to integrate the public resources into their own application, and even can not gain solutions. Hence, along with the widespride use of the Android devices and combined with current application requirements, the research and implementation of instant messaging system based on the Android platform has great practical significance.This thesis first discusses the development of current instant messaging system and the Android smartphone operating system. Combined with current real application circumstances, this thesis proposes an instant messaging solution which is on the basis of XMPP protocol and H.264 video compression standards, and implemented on the Android platform. Then, this thesis systematically analyzes the XMPP protocol and H.264 standard, and optimize these two protocols. The performance comparision before and after the optimization is provided. Based on the optimized XMPP, the basic functions such as text chats, emoticons chats, voice chats, file transfer, message forwarding, feeling communication, and chracter recognition are implemented. Based on the optimized H.264 and the real-time transfer protocol RTP/RTSP, the real-time video communication is implemented. Finally, the function, performance, stress and compatibility of the implemented instant messaging system are tested in detail, both on the Client and the Server,which verifies the feasibility of the system.This theis provides an available instant messaging system which both meet the real application requirements and offers a instant messaging solution based on Android for the small and medium-sized enterprises and the sofrware development lovers. Low-cost of the development and high-scalability of the system are achieved via the open-source XMPP and H.264.The test on Android devices demonstrates that all the functions can be normaly used and provides a good user experience, which offers a feasible solution for both enterprises and individuals.