前端开发导入jar包库： https://www.webjars.org/
freemarker语法：手册：http://freemarker.foofun.cn/
https://blog.csdn.net/qq_35376421/article/details/81095656
https://blog.csdn.net/JYL15732624861/article/details/81806179
https://blog.csdn.net/nojob1year/article/details/83767689
https://blog.csdn.net/qq_34253619/article/details/83824956