基于Web的应急成品粮调度系统实时性通信的研究与实现

发布时间：2018-07-13 15:59

【摘要】：在应急成品粮调度系统中,应急车辆与指挥平台系统之间的双向实时通信功能起到关键作用。目前,最常用的实时Web通信技术方案是基于HTTP协议的Ajax的长轮询。但是由于HTTP协议的连接是不持久的,所以需要客户端与服务器端进行多次请求连接,存在着数据传输延迟和浪费网络资源的问题。.本文首先分析了目前比较成熟的实时Web通信技术方案,比较了各方案的特点以及存在的一些问题。深入研究了 WebSocket协议的实现原理及关键技术,针对应急成品粮调度系统的实时通信的设计目标,采用WebSocket技术来实现实时通信功能,提高了应急通信的实时性。针对应急实时通信系统的高并发请求时的服务器性能问题,本文对Nodejs技术进行了研究。通过比较基于Nodejs技术的服务器与基于HTTP协议的服务器的工作原理,利用Nodejs技术的性能优势来解决高并发请求问题;针对应急实时通信系统的查看历史消息数据时的实时性问题,本文对Htm15本地存储技术进行了深入研究,利用Html5本地存储方式来代替传统的网络请求方式,提高数据获取的实时性。最后本文提出了一种基于WebSocket+Nodejs+IndexedDB的技术方案,开发了应急实时Web通信系统。该系统通过了功能和性能测试,达到了系统的设计要求。
[Abstract]:The bi-directional real-time communication between emergency vehicle and command platform plays a key role in the emergency grain dispatching system. At present, the most commonly used real-time web communication scheme is long polling of Ajax based on HTTP protocol. However, the connection of HTTP protocol is not persistent, so it is necessary for the client to request the connection with the server for many times, which has the problem of delay of data transmission and waste of network resources. In this paper, we first analyze the current mature real-time Web communication technology, and compare the characteristics of each scheme and some existing problems. The realization principle and key technology of WebSocket protocol are deeply studied. Aiming at the design goal of real-time communication of emergency grain dispatching system, WebSocket technology is used to realize real-time communication function, which improves the real-time performance of emergency communication. In this paper, Nodejs technology is studied to solve the server performance problem of high concurrent request in emergency real time communication system. By comparing the working principle of Nodejs based server and HTTP server, this paper makes use of the performance advantage of Nodejs technology to solve the problem of high concurrent request, and the real-time problem of viewing historical message data in emergency real-time communication system. In this paper, the Htm15 local storage technology is deeply studied, and the Html5 local storage method is used to replace the traditional network request mode to improve the real-time performance of data acquisition. Finally, this paper presents a technical scheme based on WebSocket Nodejs IndexedDB, and develops an emergency real-time Web communication system. The system has passed the function and performance tests, and achieved the design requirements of the system.
【学位授予单位】：北京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP393.09

【参考文献】