Merge pull request #9 from Goldfish9593/refactor

去除大量不必要的内部类
修复 bug#1

1. 修复 bug#1
2. 去除登录框中用于调试的用户名密码初值
修复 NullPointerException 错误
Merge pull request #11 from Goldfish9593/bug#1

Bug#1 已经解决
Merge pull request #12 from Goldfish9593/master

主分支合并到开发分支 #1
Merge pull request #13 from Goldfish9593/develop

主分支合并到重构分支 #1