【正文】 ost, fast munication and facilitate information exchange and data transmission. Currently used widely in the chat tool are Tencent , Net meeting, MSN, etc.In the paper, firstly I discuss the background of the development of the system and simply introduce the development tools and key technologies used. Secondly I analyze the research and design objectives to the significance of the system. Through the system requirements and feasibility analysis, I determine the functional modules of the system and draw the corresponding function block diagram, block diagram. Then according to the results of the overall system design, I design the structural of the system. The development of the Inter chat system is designed based on open Java application. It can be dynamic, realtime information transfer and efficient interaction so that it can deal more effectively with customer requests, easy to maintain and update. The system will use the client / server architecture model, which includes the client program and server programs plus serverside database used to store customer data. By using the socket class provided by java and java multithreading capability，we can deploy various services on a different port and a number of different processes can be run simultaneously in a single program. Clients send information to the server through the socket in order to achieve multipointtomultipoint chat.Key words： Java, interactivity, the Socket class, multithreadedIII目錄第 1 章　 緒論 ...........................................................................................................................................1　 課題背景 .....................................................................................................................................1 開發(fā)技術(shù) .........................................................................................................................................1 Java................................................................................................................................................1 TCP/IP........................................................................................................................................3 Socket........................................................................................................................................4 開發(fā)工具 ........................................................................................................................................5 Eclipse......................................................................................................................................5 StarUML......................................................................................................................................6第 2 章 系統(tǒng)需求分析 .............................................................................................................................7 基本功能需求 ................................................................................................................................7 性能需求 ........................................................................................................................................7 界面需求 ........................................................................................................................................7第 3 章 系統(tǒng)設(shè)計 .....................................................................................................................................8 系統(tǒng)功能設(shè)計 ................................................................................................................................8 系統(tǒng)總體設(shè)計 ................................................................................................................................9 系統(tǒng)方案設(shè)計 ............................................................................................................................9 系統(tǒng)功能模塊圖 ........................................................................................................................9 系統(tǒng)類圖 ..................................................................................................................................10 系統(tǒng)用例圖 ..............................................................................................................................11 時序圖 ......................................................................................................................................12 活動圖 .......................................................................................................................................12第 4 章 系統(tǒng)實現(xiàn) ...................................................................................................................................17 數(shù)據(jù)庫連接實現(xiàn) ..........................................................................................................................17 登錄、注冊功能