摘要随着移动互联网的快速发展，智能手机已被广泛使用，网络活动已深刻影 响着人们生活的方方面面。智能手机给人们生活日常提供了很多便利的同时也 带来了安全隐患。基于 Android 系统的发展迅猛，Android 系统为智能手机提供 了强大的业务处理能力。各种 APP 应用软件在 Android 平台得以开发，丰富了 移动终端的用户的应用。随着智能手机终端处理能力逐渐增强，人们对文件安 全处理和文件共享的需求也日益增多。利用智能手机在无线局域网中实现文件 安全共享，可以很大程度上满足人们的需求并提供便利。78331

本文针对上述需求，运用 Android 开发环境，设计并实现了一个文件安全 共享的应用软件。该软件可以实现 Android 智能手机在局域网内进行文件安全 共享，使移动终端处于同一个局域网，通过使用 TCP 传输协议让其进行双向连 接。为了实现安全共享，对共享文件进行了 AES 加密，使文件内容以密文的方 式在传输通道中传输，降低文件内容被窃取和丢失的风险。

本系统开发中，通过对 Android 系统的学习和分析，以 Java 语言为基础， 完成了文件共享、文件加密和文件解密等模块的设计与实现，并对各个功能模 块进行了可用性测试和安全性测试。测试结果验证了本软件设计的有效性和安 全性。

毕业论文关键词：Android；文件共享；文件加密；局域网；AES

Abstract With the rapid development of mobile Internet, smart phones have been widely used,and network activities have a profound impact on all aspects of people's lives。 When providing a lot of convenience to people's daily life, smart phones bring security risks。 Based on the rapid development of Android system, Android system provides a powerful business processing capability for smart phones。 A variety of APP applications developed in the Android platform enrich the application of mobile terminal users。 With the development of intelligent mobile terminal processing capabilities, the demand for file security and file sharing is also increasing。 Using intelligent mobile phone in the wireless local area network to realize the sharing of files, it can largely meet the needs of people and provide convenience。

According to the above requirements, this paper designs and implements a file security sharing application software by using Android development environment。 In the local area network, the software can achieve Android smart phones to share files securitly。 Two mobile terminals are setted in a same local area network, than they can connect two-way connection of FTP file。In order to achieve security sharing, the file that will be shared is encrypted by AES, so that the content of the file is transmitted in the transmission channel, and the risk of stealing and losing is reduced。

By studying and analysising the Android system, we use Java language to achieve module design and implementation of the file sharing, file encryption and file decryption。And each function module of the system has been tested for usability and security。 The test results verify the validity and security of the design    of the software。

Key words: Android; File Sharing; File Encryption; Local Area Network; AES

目 录

第一章  绪  论 1

1。1 课题研究背景 1

1。2  国内外研究现状 1

1。3  研究意义和目的 2

1。4 论文结构安排 3

第二章  相关技术简介 4

2。1  文件共享