In the wake of increasing penetration of mobile devices, and the changes of people’s need for communication, communication means not noly traditional phone call and message. More and more people use instant messagers which has more powful functions and are free. However, different instant messagers have different emphasis. For the demand of customized business, there is no suitable software to realize, so the development of enterprise communication system is necessary.A good communication system, there are several fundamental and important function to be guaranteed. To ensure the reliable communication, which guarantee the communication security and real-time communication, make sure that the message can be sent to the receiver in a reliable way. To ensure the good user experience, using the offline caching or using the information in the local cache is popular. To ensure when many users the system can also have a lower response time, concurrency control mechanism is in order to improve the system responsiveness under the condition of high concurrent. These features is the foundation of communication system. O nly these functions are designed wel, can realize the application layer of the function more efficiently.This paper is based on researching other instant messagers, combines the company’s needs of reliable and extensible, uses open source Openfire server, designs and realizes company communication system. Using XMPP protocol to communicates between client and server. Insuring high reliability by data encryption, local data caches and affirming received message. Realizing offline caches according to local database caches and file caches. Adopting cache updating strategy to update caches and cache clearing startegy to clear caches. Using optimistic lock mechanism and concurrent programming principles to improve system’s concurrency. The achievement of these principles guarantee the usability, reliability and augmentability of company’s communication system. It has got good effect in a real world application. |