【作者】 徐越；

【导师】 张瑞生；

【作者基本信息】 兰州大学 ， 计算机应用， 2007， 硕士

【摘要】 对等网络P2P(Peer-to-Peer)技术是目前国际计算机网络技术研究领域的一个热点，它将网络的控制权归还给了用户，给人们最直接，最广泛的交流。P2P技术使得边缘节点的资源得到充分利用了，扩充了信息的来源和流量，具有灵活和可扩展性等很多优点。JXTA是Sun公司于2001年推出的开放性对等网络研究项目，其主要目的是致力于从所有的P2P系统中分离出系统通用的需求，建立一个最薄的、虚拟的、通用的开发平台。它的普遍性、平台无关性、互操作性使它日益成为P2P应用开发的标准。文件的交换与共享是P2P技术的基础性应用，人们一直在探讨更为安全，可靠的相关应用，目前存在很多的共享软件如Napster，Gnutella，Freenet等。虽然他们具有不同的P2P网络结构，也经历了长时间的发展，但是对用户所共享的文件的安全和可用信息还未涉及，使得用户下载文件时，并不能预知文件的安全程度和文件是否可用的风险程度。本文分析了以往的文件交换和共享软件的特点，研究了JXTA网络平台的相关技术，特别是JXTA构架、组件及其核心协议，并在此平台上，借助于对等组服务的普遍性，设计了一个具有信任评价的CMS(Content Manage Service)系统，同时给出了系统主要功能的实现方法和代码。此系统允许用户在使用传统的文件共享与交换功能的同时，能够对已知文件的安全和可用性进行信任评价以供其它用户来提取，也可以获取其它用户对相关文件的信任评价信息。此系统保证了服务的可用性，加强了文件实用性的控制，不仅为P2P用户提供了更多的文件信息，在一定程度上弥补了在分散式网络结构下无法获取用户共享文件的安全及真实信息的不足，同时也为加强网络服务和文件管理提供了一种新的思路和解决方法。更多还原

【Abstract】 Nowadays, the technology of P2P (Peer-to-Peer) network is a hot spot in the field of international computer network. It returns the domination of the network to the user and helps people to communicate with each other by the most directly and extensive way. The P2P technology makes full use of the resources of edge node. It increases the capacity and has a lot of advantages, such as flexibility and scalability. JXTA, an open P2P project by Sun Corp, begun at Apr.2001.Its target is to extract the general requirements from all P2P systems, so as to create common underneath protocols, which are used to normalize and standardize all kinds of P2P core, services and applications. JXTA provides a thin, universal, virtual platform with the basic functions necessary for a P2P network. Because of its universality, platform independence, interoperability, it has been the standards of the P2P application.The exchanges and sharing of files are the basic application of the P2P technology and the researching on it has never stopped. There are many applications of the file sharing, such as Napster, Gnutella, Freenet and so on. These applications are working in different P2P network structures and have developed for a long time. However, the safe information of sharing file that the user provides has not been involved. The result of this situation is: while the customer downloads the file, they can’t predict the available and safe risks of the file.This paper analyzes the features of some software about exchange and sharing of files, studies the technology of the JXTA network platform, especially the framework, basic components and core protocols about it. With the help of the universal service in peer group, the author designs a CMS (Content Manage Service) system which has a trust evaluation in this platform. This paper lists the implementation code of some main functions. The system allows users to evaluate the safety and availability about the files at the time of using the traditional functions such as sharing, downloading. Users also can access other files information related to the evaluation of the trust. The system can ensure not only the availability of service, but also the usefulness of files. It helps the user of P2P obtain more informations of the file, and provides a new idea for network services and managing of sharing files in distributed P2P network structure.更多还原