【作者】 陆晨；

【导师】 周健；

【作者基本信息】 合肥工业大学 ， 计算机应用技术， 2003， 硕士

【摘要】 当前的网络应用中，C／S模型是主流。而随着分布式计算的深化和网络技术的进一步发展，对等式网络模型(P2P)开始受到重视，并成为最近的技术热点之一。 P2P模型与C／S模型相比，最大的不同是降低了对服务器的依赖及其分散控制，一些P2P模型甚至不需要服务器。P2P系统的冗余性很好，没有单一的失败点。P2P模型可以作为C／S模型的补充。当然，作为一项新技术，P2P模型目前还很不成熟，甚至还没有公认的标准协议。 论文尝试研究P2P的模型及应用。文章首先概述了P2P的定义，分类和应用范围等一系列问题；然后试着从现有的各种P2P应用中，分析总结出其不同的实现模型，考察其内部机制，以及各种模型的优缺点；还用Java语言实现了其中多播模型的基本框架；接着论文阐述了对等计算如何穿透防火墙而实现通信以及安全性，探讨了几种作者认为行之有效的新技术。论文的最后，把新的P2P技术应用到传统的即时通信应用软件领域，即在Jxta协议的基础上构建不需要任何中心服务器的通信应用。更多还原

【Abstract】 In current network applications, C/S modal is the mainstream.But with the quick development of the distribute computing and new network technology,more and more people focus their attention on P2P modal in recent days.The main difference between P2P modal and C/S modal is that the former doesn’t rely on a server,thus control is distribute.Some modals of P2P even don’t require a server.The P2P modal has excellent redundancy.No single fault point in P2P modal.P2P modal can be a good complementarity of C/S modal.And of course,as a new technology,P2P modal is not maturate.It Even hasn’t a standard protocol till now.This thesis try to study the modal of P2P and its application.The thesis firstly gives the definition of the P2P technology,and try to classify the P2P modals.By researching the existing P2P applications and softwares’s implementation,this thesis want to conclude their different implementary modals,their merits and their shortcomings,and also study deeply to their inner mechanisms.And it gives and implements a basic framework of multicast discovery modal using Java language.Then the thesis discusses how the P2P computing communicates with each other though many kinds of firewalls and some secure problems in P2P area.The author discusses some practical feasible new methods.At the last part of this thesis,it try to apply this new P2P technology to the traditional instant message software area.That is,it want to build messaging application without a central server using protocol jxta.更多还原