Settings→Editor→General→Auto Import
选中Optimize imports on the fly和Add unambiguous imports on the fly
Optimize imports on the fly：自动去掉一些没有用到的包
Add unambiguous imports on the fly：自动帮我们优化导入的包
Settings→Editor→General→Auto Import
选中Optimize imports on the fly和Add unambiguous imports on the fly
Optimize imports on the fly：自动去掉一些没有用到的包
Add unambiguous imports on the fly：自动帮我们优化导入的包