The Design And Implementation Of Content-Based Publish/Subscribe Based On B/S Mode

With the developing of informatization, the massive Data processing has become an urgent problem and this puts forward higher requirement on distributed systems. The traditional paradigms such as message passing, RPC and shared spaces all have the coupling problems. The publish/subscribe interaction paradigm is claimed to provide the loosely coupled form in such large scale distributed system. The loosely coupling can be decomposed in three sides:time decoupling, space decoupling and synchronization decoupling. On the other hand, with the rapid development of the internet the web application with B/S (Browser/Server) mode has been used in most areas. Compared to the traditional C/S (Client/Server), it has lots of advantages such as cross-platform, easy upgrade and maintenance. In summary, implementation of the publish/subscribe system in B/S will produce wide application prospect.This paper focuses on the design and implementations of content-based publish/subscribe system in web. The primary work and innovations of this paper include:First, this paper discusses different kind of publish/subscribe system such as channel-based, topic-based, content-based, type-based and hybrid system by a detailed study of the development of publish/subscribe. And we analyze the advantages and disadvantages of their flexibility and expression capacity. We retain the advantages of the original topic-based system and propose a method to change the system to content-based system. We focus on the way to get the key words in content-based system by using DFA (Deterministic finite automation) double-array method.Second, by using ExtJs which is one framework of Ajax, the web application has been designed and implemented. This paper combines with the usage scenarios, analysis of the original C++release of the publish/subscribe middleware’s features and proposes a approach by using JNI to transplant it. According to the web development trend, we implement the system based on ExtJs which is one of the RIA technologies. It can help us to realize the system with better user experience, reducing the consumption of resources and better support for publish/subscribe system characteristics than the traditional ways.