中文摘要：

当前智能手机之间文件传输方案可分为依托互联网和自组网2类，基于互联网的方案大多采用P2P直传或者通过服务器转发传输，无法访问互联网的情况下大多采用WiFi热点技术或蓝牙技术建立自组网进行文件传输。但在网络环境动态变化的情况下，这2种传输方式间的切换会导致文件重传，浪费已传输的资源。针对此问题，本文提出一种在网络环境动态变化的情况下文件传输的方案，解决在不同网络环境下文件传输路径的优化选取以及跨网络的文件续传问题，并提高文件传输速度。

英文摘要：

Nowadays,the schemes of file transfer between smart-phones can be divided into two categories,Internet-based and Ad-hoc-network-based. When the clients connect to the Internet,they can use P2P direct technology or a file server to forward files. Otherwise,WiFi hotspots or Bluetooth technologies are used to set up Ad-hoc networks between clients to realize file transfers. But in the case of network environment changing,the switch between the two schemes will lead to retransmission of files,and the parts that have already been transferred will be wasted. To solve this problem,this article puts forward a file transfer scheme which can adapt to dynamic network environments,choose the optimized route for users,and improve the speed of file transmission.