Q: Macbook Pro software upgraded to OS X EI Capitan. Now unable to load any web pages except Youtube, Yahoo and Facebook, ect..

I upgraded my MacBook Pro  OS X to EI Capitan. Now unable to load any web pages except Youtube, Yahoo and Facebook, ect... Once the machine startup, there's a massage popping up asking ( To use the '' java '' command-line tool you nee to install a JDK ). When  I click on more info link, the web page doesn't load as well. I tried time machine to downgrade the software to previous OS X , but since i don't have any OS X backup, it wasn't successful . any tips to fix this problem would be greatly appreciated .