Those who do not like PHP as much as i do or many others but still want to enjoy things in the php way like, wordpress , now now an option in java also. nWordpress is an alternate to wordpress(written in php) written completely in java.
Numiton says the following about their product nWP as :
Blogging for Java
nWordPress is the Java counterpart of the WordPress project version 2.5.1. It is an easy to install and lightweight blogging engine with a rich administrative interface, nWordPress lets you concentrate on writing quality content.
nWordPress is an open-source project under the GPL license, same as WordPress. It currently provides almost all of the original functionality, with comparable performance.
Under the hood, nWordPress is built on the Spring MVC framework.
I think its a good start for java lovers, because i could not find much of open source ready to use applications in java as much as i can find in PHP. If java is seen as an enterprise language then why java should bother about such a small project like wordpress 
This claims that PHP is soon going to enter into enterprise world or almost has done it. Java, you have got competition :p
Cheers !!
Realin !
The short answer is: because Java needs popular open-source projects.
There’s no better cure for a language than lots of people enthusiastically using it. And there are lots of positive energies in open-source communities compared to traditional enterprise environments.
Yeah this is what it is, turning back to small open source projects just to shove that “Yeah we exist !!”
I am not against java at all, but still BMW wont start making world’s cheapest car just to ensure that many of them use it