摘要:随着互联网的快速发展，即时通讯工具已经作为一种重要的信息交流工具，受到越来越多的网民的青睐。目前，出现了很多非常不错的聊天工具，其中应用比较广泛的有Netmeeting、腾讯QQ、MSN-Message等等。该系统开发主要包括一个即时通讯服务器程序和一个即时通讯客户程序两个方面。前者通过Socket套接字建立服务器，服务器能读取、转发客户端发来信息，并能刷新用户列表。后者通过与服务器建立连接，来进行客户端与客户端的信息交流。其中用到了局域网通信机制的原理，通过直接继承Thread类来建立多线程。开发中利用了计算机网络编程的基本理论知识,如TCP/IP协议、客户端/服务器端模式（Client/Server模式）、网络编程的设计方法等。在网络编程中对信息的读取、发送，是利用流来实现信息的交换，其中介绍了对实现一个系统的信息流的分析，包含了一些基本的软件工程的方法。经过分析这些情况，该局域网聊天工具采用Eclipse为基本开发环境和java语言进行编写，首先可在短时间内建立系统应用原型，然后，对初始原型系统进行不断修正和改进，直到形成可行系统

关键词：局域网; 聊天; Socket; Java

Abstract:Along with the fast development of Internet, the communication-on-time tool has already become one kind of important communication tools and received more and more web cams favor. At present, many extremely good communication tools have appeared. For example, net meeting, QQ, MSN-Message and so on. This system development mainly includes two aspects of the server procedure of the network chat and the customer procedure of the network chat. The former establishes the server through the Socket, the server can read and deliver the information which client side sends, and can renovate the users’ tabulation. The latter make a connection with the server, carries on communication between the client side and the client side. With the LAN correspondence mechanism principle, through inheriting the Thread kind to establish the multithreading directly. In the development, it uses the elementary theory knowledge which the computer network programmers. For example, TCP/IP agreement, Client/Server pattern, network programming design method and so on. In the programming, it realizes reading and transmission of the information, that is, information flows realize the information exchange, introduce information flow analysis for realizing a system, in which contains some basic software engineering methods. After analyzes these situations, this LAN chatting tool takes Eclipse as the basic development environment and compiles in java language. First, it will establish the system application prototype in a short time. then, for the initial prototype system, it needs constantly revised and improved, until a viable system.

Key words: LAN; Chat; Socket; Java