【作者】 付大为；

【导师】 周春光；

【作者基本信息】 吉林大学 ， 计算机应用技术， 2008， 硕士

【摘要】 P2P作为一种新兴的技术已经得到了越来越广泛的应用,但是由于众多P2P系统各自独立,已经限制了P2P的发展。Sun公司提出的JXTA平台正是为了解决这一问题。JXTA具有的互操作性,平台无关性和广泛性使得它成为了P2P系统开发的理想平台。本文在JXTA协议的基础上,提出了一个P2Pdownload应用框架模型,并且应用此模型成功的开发了一个P2Pdownload系统,其中对资源共享的原有方式做出了改进,提高了资源搜索效率,同时丰富了资源下载功能,并且验证了此模型的可行性。使用本模型开发的系统具有健壮性,安全性高,高性能等优势。本课题的研究不仅分析了P2P的技术和应用,并且使JXTA平台进行P2P应用的开发方面做了一些探索,为日后对P2P的研究奠定了一定的基础。更多还原

【Abstract】 P2Pisappliedtodocument distribution,voiceservices, streamingmedia,and other various fields now. But there’s no uniform standard networkprotocolforiteventhoughitisusedinvariousforms,anditsarchitectureandorganizational forms are also constantly developing. According to statistics,P2P applications for the operators have reached 60 percent of the total to 80percent. The flow generated by P2P application is non-balanced, concealedand hidden. There are many questions to be resolved, for example, thecopyright of P2P, the distribution of legal documents. How to realize thesecurity of the data access, route, user authentication and identitymanagementisanimportanttopictoo.The multitudinous P2Psystems do their own wayand in them own field,they has formed l lot of P2P isolated island nowadays. To resolve thisquestion, Sun Corporation proposed a viewpoint:“only exchanged candisplay P2P truly superiority, just like Instant Messaging (IM), more humanjoined in, more valuable this system is”in 2000 summer. And then, theyreleasedaplatform–JXTA.AprimarydesignprincipalofJXTAistoprovidea platform that embodies the basic P2P network functions. The otherprincipal is seeking for“building blocks”composed of a system withminimum number and simple concept. If find“building blocks”, theywill bethebasicmodelforP2Psystems.This paper analyzed the P2P technology characteristic, summarized thethree kind of P2Pmodels and each kind of domain applications and analyzedthe existing P2P application flaw and the insufficiency, then proposedintroduces the JXTA platform in the P2P application development thetentative plan. The author putted forward a framework for P2P download–P2Pdownload model. Then this paper summarized the characteristic whichthe P2P application should have, and proposed the model three layers(includingcorelayer,logiccontrollayer,applicationlayer).The core layer encapsulates the minimal and essential primitives that are common to P2P networking. It includes building blocks to enable keymechanisms for P2P applications, including discovery, communicationtransports, the creation of peers and peer group, and associated securityprimitives. Core layer provided the basic functions of the applications onlynotactualapplications.The logic control layer includes network services that may not beabsolutely necessary for a P2P network to operate, but are common ordesirable in a P2P environment. Examples of network services includesearching and indexing, directory, storage systems, file sharing, distributedfile systems, resource aggregation and renting, protocol translation,authentication, and PKI (Public Key Infrastructure) service. To develop theapplication layer easier and advantageous, logic control layer provides thelogicfunctionsfortheapplicationlayer.The application layer includes implementation of integrated application,such resource sharing, resource searching, resource downloading and manyothers.Thislayerlocatesthetopofthemodel.Finally, this paper realized the detail of P2Pdownload system, includeuser authentication, peer creating and join, advertisement creating、publication and discovering, input or output pipe building, message code,message receiving and sending, resource sharing、searching and download,systemGUIdesignandsoon.The model designed in this paper is not only inherits the merits of theoriginalmodel,butalsoimprovesit.In original model, the advertisement and the sharing resource are savedin the same pipe, this reduces the efficiency of the resources utilization. Inthis paper, the author created the different pipes for saving the advertisementandtheresourcerespectively.Additionally, original model doesn’t provide the function of distributedresource searching. In this paper, the author finished preliminary explorationfordistributedresourcesearching.This paper proposed P2Pdownloadapplicationframemodel on thebasis of JXTA protocol, and develop the P2Pdownload system to confirm themodel. There are lots of incomparable superiorities in P2Pdownload system,such as: expansibility, robustness, high performance and high security. Theresearch on this topic explores the potential of the JXTA and lays thefoundationforthedevelopmentofP2Papplication.更多还原