..

*

According to this..
<http://java.sun.com/javaee/javaserverfaces/1.2/docs/tlddocs/h/outputText.html

..either a style or styleClass should do it, but
they are used slightly differently.  The style is
probably 'simpler' for the developer, but the
styleClass is more effiecient for pushing HTML
out to the client (less bytes required).

But, what happened when you tried it?

Using stefanonmm's suggestion, it would look like
this, I expect**.

<h:column>
<h:outputText style="white-space: nowrap;"/>
</h:column>

* Odd you should say that, after putting no less than
4 sentences with no first capital letter!  This is how
I would expect them to appear..

"But i need to apply css to columnContent?"
"Should be it right?"
"Sorry for non capitalized letter!"
"I'll be more carefull"

The last one also needs a full-stop '.' character,
but otherwise, it is a sentence.  There are also
other parts of those sentences that should be caps.,
like the word 'I' (which is *always* capitalised), and
the acronym 'CSS'.

** I know more about HTML, than I know about
whatever Java tool or API is being used to
generate the HTML.