P2P网络平台JXTA的应用研究

【作者】 代寸宽；

【导师】 傅光轩；

【作者基本信息】 贵州大学 ， 计算机应用技术， 2007， 硕士

【摘要】 对等网络技术(P2P)作为一种新兴的技术，近些年来得到快速的发展。P2P中的每个节点既是资源的提供者，又是资源的获取者。与传统的模式相比，具有无可比拟的非中心化、可扩展性强、健壮性、高性能／价格比、安全性高等优势。同时P2P技术具有广阔的应用前景，已经应用到即时通讯、文件共享、对等计算、精度搜索、企业应用、电子商务和电子游戏等领域。但是众多P2P系统均是各自为政，形成了一个个P2P的孤岛。这样与P2P设计的分布式的初衷相背离了。在2000年的夏天，Sun公司提出了“只有互通才能真正发挥出P2P的优势，就好像即时通讯IM(Instant Messaging)，能互连的人越多，越有价值”的观点，并出面发布一个平台—JXTA平台。JXTA不仅仅是一个对等网络计算平台，关键的是它实现一个与网络、编程语言和平台无关的支持多种P2P应用的平台。JXTA平台具有互操作性、平台无关性、广泛性等特性，是P2P应用开发的理想平台。本论文通过对P2P平台JXTA的三层体系结构和协议的分析研究，掌握基于JXTA平台开发P2P应用的核心技术和过程，从而运用JXTA提供的一套数量少，概念简单的协议构建P2P应用系统。最后，本文提出基于JXTA平台，集成5Ms和J2EE技术设计并构建一个分布式工作流平台，简称PDWP。论文首先给出了PDWP的网络架构图和体系结构图，并描述了PDWP要实现的一些功能；接着按功能模块对PDWP的具体实现进行了详细地讲述，主要模块包括P2P底层网络的建立、工作流的定义和发布、消息的接收和发送以及任务的启动、中止、挂起、恢复和推进；最后通过实验对PDWP在提高设备分散、信息化建设和网络条件不同的企业之间信息交互和协作的效率上的性能进行评价。论文首先阐述了P2P网络计算的历史与发展现状以及P2P典型应用；然后详细分析研究新的对等网络计算平台——JXTA，包括JXTA的体系结构、基本术语、核心协议和标准协议：最后给出开发实例——一个建立在JXTA平台上的分布式工作流平台。更多还原

【Abstract】 The peer-to-peer network technology (P2P) as the most up and coming technology, has developed very fast in recent years. In P2P each node is the resource provider, also the resource extraction. Compares with the traditional pattern, it has lots of incomparable superiorities, such as: non-centralization, expansibility, robustness, high cost performance and higer sercure. And P2P technology has the broad application prospect, applies unceasingly to instant messaging, file sharing, coordinated computation, precision search, enterprise application, electronic commerce and computer game etc.But the multitudinous P2P systems do their own way and in them own field, them has formed a lot of P2P isolated island. This departed from the original P2P design intention-distributional share. In 2000 summer, Sun Corporation proposed a viewpoint: "only exchanged can display P2P truly superiority, just like Instant Messaging (IM), more human joined in, more valuealbe this system is". And released a platform—JXTA platform. JXTA is not merely a peer-to-peer network calculates platform, what is essential is it is designed to be independent of programming language, transport protocols/networking platforms and system platforms. It has the features such as, interoperability, platform independence and ubiquity, so it become a ideal P2P application develop platform.In this paper, we master the core technology and process of developing P2P application through analyzing the architecture and the protocols of JXTA. So we can use a set of fewer and simpler protocols to design P2P application.In the end, we use JMS and J2EE technology to design a platform of decentralized workflow, for short PDWP, it based on JXTA platform. The paper first presents the network structure and the infructure of PDWP, and describes PDWP’s function; Then pressed the function module to carry on to PDWP specific implementation in detail narrated, the main module including the the creation of peer-to-peer network, the definition and issue of workflow,the receiving and sending of message, and starting, stoping, suspending, resuming, continuing of the task; Finally, we experimentalize to evaluate PDWP’s performance versus traditional workflow management system.In the paper, we describe the history of network computing and the developing status of P2P application in the first, then we discuss the platform of peer-to-peer computing—JXTA in detail. It involves the architecture, the term, the core protocols and the standard protocols of JXTA. Finally, we give a developing example, it is a platform of decentralized workflow based on JXTA.更多还原