【正文】 more numerous, as the overseas ICQ system, the OICQ system that invented by Tencent Co., and so on. So we create a work chat medium just like the . Java work programming based on the power, the use of Java designed to prepare graduates a chat system.In general, the majority of the chat tool for client and server program in addition to serverside storage of customer data for the database, the system uses a client / server architecture model the adoption of Java provided Socket class connect client and server and between the client and server municate with each other, as the chat is to provide pointtomultipoint and multithreaded Java function to be pleted by using multithreaded chat and more pointtomultipoint, database management system with SQL Server2022 the pletion and adoption of JDBCODBC Bridge access the database.The system built on the JAVA platform, the system design using objectoriented technology and objectoriented design principles. System uses the C / S structure, client and clientside and serverside client and send messages through Socket. The use of JAVA language, development tools using Eclipse. Design and Implementation of serverside process, the use of multithreading technology, which can process in a single run at the same time a number of different threads, the implementation of different tasks. Procedures greatly enhanced the use of server resources.Chat system will allow people to plete chat to more friends，and the system can add, delete somebody，can deal with new user registration, send messages, receive messages and so on. Keywords : Multithreading 。使用 JAVA 語言編寫，開發(fā)工具采用 Eclipse?；?Java 網(wǎng)絡編程的強大功能，本次畢業(yè)設計使用 Java 編寫一個運行在 版本以上的即時通訊軟件。 一般來說，聊天工具大多數(shù)由客戶端程序和服務器程序外加服務器端用于存放客戶數(shù)據(jù)的數(shù)據(jù)庫組成，本系統(tǒng)采用客戶端/服務器架構模式通過 Java 提供的 Socket 類來連接客戶機和服務器并使客戶端和服務器之間相互通信，由于聊天是多點對多點的，Java 提供的多線程功能用多線程可完成多點對多點的聊天，數(shù)據(jù)庫管理系統(tǒng)用 SQL Server2022 完成并通過 訪問數(shù)據(jù)庫。服務器端設計與實現(xiàn)過程中，采用了多線程技術，可以在單個程序當中同時運行多個不同的線程，執(zhí)行不同的任務。 Client/Server 。TCP/IP目 錄1 緒論 .............................................................................................................................................1 國內(nèi)外聊天系統(tǒng)的研究現(xiàn)狀 .......................................................................1 JAVA 語言 ......................................................................................................2 Java 的發(fā)展歷史 .....................................................................................2 Java 的特點 .............................................................................................3 Java 與 Inter .......................................................................................4 SOCKET 編程 ..................................................................................................4 關于 TCP/IP 協(xié)議 ..................................................................................4 服務器和客戶機 ....................................................................................5 本文內(nèi)容安排 ...............................................................................................62 需求分析 ...................................................................................................................................7 可行性研究 ...................................................................................................7 可行性分析 ............................................................................................7 系統(tǒng)功能需求 .........................................................................................7 系統(tǒng)性能需求 ........................................................................................8 系統(tǒng)運行需求 ......................................................................................8 數(shù)據(jù)流圖 .......................................................................................................8 頂層數(shù)據(jù)流圖 ........................................................................................8 一層數(shù)據(jù)流圖 ......................................................................................9 二層數(shù)據(jù)流圖 ......................................................................................93 概要設計 .................................................................................................................................11 系統(tǒng)實現(xiàn)原理 ..................