整个项目分为两个idea项目：Server端和Client端，每一个都是独立项目。
没有用到UI编程，输入输出使用的是Scanner和System.out
有两个界面，初始界面和二级菜单界面。
在初始界面可以进行注册、登录和退出系统，由于没有用到数据库，所以每一次重启系统都需要注册。
登录成功后进入二级菜单，可以显示在线用户列表，群发消息，选择在线用户进行私聊，发送文件和退出功能。
在服务器端可以发通知给全体在线用户，也可以退出发送功能。
所有的通信全部使用的Socket类实现，传送数据使用ObjectInputStream和ObjectOutputStream类实现。
java版本为jdk1.8
......
React
A declarative, efficient, and flexible JavaScript library for building user interfaces.
🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
Typescript
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
An Open Source Machine Learning Framework for Everyone
Django
The Web framework for perfectionists with deadlines.
Laravel
A PHP framework for web artisans
Bring data to life with SVG, Canvas and HTML. 📊📈🎉
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
Some thing interesting about web. New door for the world.
A server is a program made to process requests and deliver data to clients.
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
Some thing interesting about visualization, use data art
Some thing interesting about game, make everyone happy.
Facebook
We are working to build community through open source technology. NB: members must have two-factor auth.
Microsoft
Open source projects and samples from Microsoft.
Google
Google ❤️ Open Source for everyone.
Alibaba
Alibaba Open Source for everyone
D3
Data-Driven Documents codes.
Tencent
China tencent open source team.
