Based On The Jxta Platform P2p File-sharing System

P2P can be simply defined that a technology can be used to exchange computer resources and services directly.Generally these services include information share and exchange,computing resource,storage resource ,etc.JXTA is a project originated by Sun Microsystem.This project is an open source project that define some standard protocols that used by P2P applications and services.The protocols can supply the general functions needed by building P2P network.The peers in different networks can communicate to each others by JXTA protocol easily.And JXTA protocol dose not depend on any operating system,any develop language and network tranport protocol.Firstly this dissertation introduce basics of P2P and JXTA.And analyze four topologys of P2P system and their resource discovery ways and their advantages and disadvantages.The RPV mechanism based on rendezvous peer is studied.The qualification of rendezvour peer,sequence of RPV and maintenance of RPV shoud be three problems that affect resource discovery.Intoduce priority of rendevous peer,level of RPV and evaluation of RPV to improve resource discovery.Analyze firewall traveral in communication between peers.And that problem can be resolved by relay peer.TLS can be a way to make communication of JXTA safe.A P2P file share system is designed, and is implementd by J2SE model.The way of creating peer group,publishing peer group,joining peer group,creating file share service ,creating file share service advertisement and improvement of RPV discovery is described.