I am an ex-Java developer. I built both enterprise and social web apps with Java technologies namely Spring Framework, Servlet, JSP, Hibernate, iBatis, Tomcat, WebSphere but recently I chose Django Framework for my MVP project www.junglesearch.net (previously jeviz.com).
Although I like Java I prefer dynamic languages for writing web applications and my dynamic language preference is Python. Python is both practical and beautiful programming language with huge ecosystem so you can find a library for anything.
There are good Python frameworks and two popular choices are Django and Flask. I chosed Django over Flask because of batteries included philosophy and some great Django libraries namely Django Rest Framework, Wagtail (Currently I am integrating wagtail to jeviz.com) and Django Channels. Plus: Django has LTS releases!
Here some comparison of Python/Django stack over Java/Spring stack:
Because of all above reasons and mainly for productivity boost I used Django for junglesearch.net and I am happy with my decision.