【2017年整理】毕业论文-基于java的网络即时通信系统.3.doc

摘 要 目前，关于即时通讯系统（Instant Messaging System）的研究是互联网中一个热门方向，尤其是关于企业级的即时通讯系统更是成为了国内外应用的热点。企业版的即时通讯软件的诞生，给企业的管理带来了新的思路和方法，提高了企业的工作效率，降低了办公费用，引发了工程应用领域的新研究热潮。即时通讯系统基本上均采用客户机/服务器（C/S）模式。在此模式下，服务器无疑是处于核心地位的。本文正是围绕即时通讯系统服务器端软件开发这一核心展开。首先，本文选择了当今流行的各种即时通讯软件，进行对比分析，确定了即时通讯系统的功能，提出了不同的即时通讯服务器的架构。其次，本文介绍了本系统使用的目前流行的一些技术，如多线程技术TCP/IP协议和OSI模型、套接字(socket)通信结构等围绕即时通讯的基本文字交流功能，设计了不同用户之间的文字通讯。本系统就是在此企业即时通信市场日益高涨的时候，采用先进的 Java Socket技术, 开发出一个 C/S模式的基于 TCP/UDP协议的网络通信系统。该系统充分利用了 Java的跨平台性, 结合目前已有的典型通讯软件 BBS和 OICQ的某些技术, 采用 TCP/UDP协议与服务器转发的技术, 扩展了文件发送的功能, 使得客户间发送文件不受防火墙限制。同时在时间允许的情况下增加语音、视频以及网络电视等功能。 关键词：即时通讯系统 OICQ C/S模式 I The Internet Messaging System Based on Java Abstract Now the research about instant messaging system is a hot direction in internet, especially the instant messaging system for enterprise group is a hot spot in practicing in the world. The instant messaging system for enterprise group brings new thoughts and ways for enterprise management, raises the working efficiency, cuts down the administrative expenses, and initiates the new trend in industrial practicing field. Instant messaging system mainly selects C/S mode. Server is the core part in this mode. This paper just bases on the development of instant messaging system software. First, this paper selects several kinds of popular instant messaging software, contrasts and analyzes each one, defines the functions of instant messaging system, advances the different structures of instant messaging servers. Second, this paper introduces some techniques which are used in this system, eg: TCP/IP, OSI and socket etc. basic communicating functions of instant messaging system, designs the characters and writing communication between different users. This system selects advanced Java Socket technique, develops a C/S mode internet communication system which is based on TCP/UDP. This system uses the Java’s multi-platform feature fully, combines some techniques of the typical instant messaging software like OICQ which exist now, se