Continue with PHP or move to Java Framework
<p>I'm building a website for my friend's startup. 
I'm currently building it on PHP, MySQL, Apache. Everything is going pretty smooth till now, but one of my friend recommends i move to a Java framework because that'd be better when the site becomes bigger.
I don't have any Java Knowledge and I have adequate knowledge of PHP but I'm a fast learner</p>

<p>Should i continue with PHP (can PHP be used for big sites?) or should i move to a Java Framework? 
Any suggestions please.</p>
