R problem of installing packages: package ‘xxxx’ is not available (for R version 3.2.2) and unable to access index for repository xxxx

I met this problem after re-installed the Ubuntu. I've got to set up the whole programming environment again...  :-{{

--- Please select a CRAN mirror for use in this session ---
Warning: unable to access index for repository http://cran.utstat.utoronto.ca/src/contrib
Warning message:
package ‘xxxx’ is not available (for R version 3.2.2) 

Checked something online. The following two helped...

http://stackoverflow.com/questions/25721884/how-should-i-deal-with-package-xxx-is-not-available-for-r-version-x-y-z-wa
http://stackoverflow.com/questions/25599943/unable-to-install-packages-in-latest-version-of-rstudio-and-r-version-3-1-1

Basically, just change to another mirror...I changed to one in US, didn't work either... Then Canada(BC), WORKed!!!!

Wired...but you can try the same cuz there might be many problems to the unavailability of a university server, which is usually the case for R mirrors...

Happy coding!