一）使用Servlet技术改写用户登录
基于实验三中的用户登录项目，使用Servlet改写登录验证功能。
（二）使用Filter技术解决中文乱码
用户登录项目中，输入用户名时可能会包含中文，服务器端处理时会出现乱码情况，使用Filter技术加以解决。(I) use Servlet Technology to overwrite user login

Based on the user login project in Experiment 3, use servlet to rewrite the login authentication function.

(II) using filter technology to solve Chinese code disorder

In the user login project, the user name may contain Chinese, and there will be code confusion in the server-side processing, which can be solved by using the filter technology.)