Since many Go packages rely on Google official packages, and Google official packages are all on Google servers and cannot be accessed directly for some reasons. After searching for many solutions, I found the simplest method. :
1. Find the address of the corresponding package on github
2. go get the package at this address
3. Create a folder with the original address of the package locally
4. Transfer the package in the github.com folder to the original address folder
Specific to the question on the title, we need to first obtain the address of the package on github
github.com/golang/net
So, use the command:
go get github.com/golang/net
Get this package, then create the golang.org/x/
folder in $GOPATH/src
and add github.com/golang/net
Cut into it so that we can import "golang.org/x/net"