idea maven cannot download sources
https://www.cnblogs.com/wwjj4811/p/10364580.html
idea 查看maven包的源码 点击download source 无法下载。显示cannot download sources
解决办法： idea terminal 终端输入
mvn dependency:resolve -Dclassifier=sources
等待下载完
然后重新查看源码，点击download source 就可以了