it is hard to compare both but in general

PHP web servers mostly run PHP by interpretation, but JSP pages are pre compiled, some commercial application servers like Bea weblogic optimize JSP to a very good speed.

there are not many high speed PHP containers.

it is harder to maintain a large PHP based  application than a j2ee  application

we are also developing some e-university solutions in our company, we have developed some systems for different universities one of them has 10,000 students and they have no problem with speed of our java application.