How to install java in ubuntu?

[Mihamina Rakotomandimby]

Luke wrote:
> Dear Mdm/Sir,

Just say "Hi," ;)

> I need to install java into my newly installed ubuntu in my laptop.

https://help.ubuntu.com/community/Java

> I also would like to know if there is any firewall built-in for ubuntu

https://help.ubuntu.com/community/IptablesHowTo

> that I can access the settings or if this OS also require any anti-virus
> software to be installed. Where can I find all these?

Antivirus is not needed _for the moment_ .
Notice that some web search would have given you all those answers... :)