java model layer, php templating and session handling and so on, html/ccs/javascript client-side

I have partially written a web application in php. It has some large data processing needs. Writing the model/controller layer in php is not fun as it isn't particularly good as far as oop and so on goes. I would like to move this logic to a java application that is simply called or accessed by the 开发者_开发技巧php. What would be the best way to go about doing this?

How do companies like google and so on work? They use php, but do they use it for model/controller/data processing-type logic? From what I can figure out, they use a lot of c++/java for this. How do they connect that to php?