Is Java or Python a better choice for an application involving data intensive algorithms employing natural language processing? I am a professional java developer with 9 years of experience. Never worked with Python but, I do not have any restraints learning it.

Still I need clarity on a couple of aspects. I hope if anyone can help, it will clear the cobwebs in my mind. I am looking to develop a machine learning project : 


With a web interface to present interactive analytical graphs and views. 
Employing a web crawler collecting data, both structured and unstructured. 
A backend crunching the data collected using machine learning and artificial intelligence and natural language processing algorithms.


While exploring options available, I found both Python and Java have extensive support and frameworks/libraries/modules available to leverage machine learning implementations.

However, working with Java gives me a sense of strongly typed programming and it can leverage the underlying CPU cores via its robust multi-threading APIs. Python on the other hand is scripted language and on the face value looks to lesser efficient when working on complex logic crunching a huge amount of data pertaining to Natural Language Processing.

I might be utterly wrong as I am not very acquainted with Python ecosystem.

Can anyone help me understand on the choice between Java and Python if I keep in mind execution speed, maintainability and community support targeted toward development of a large, scalable and robust machine learning/artificially intelligent application ?
I work with python and java in big-data settings every day.

python is definitely my language of choice when researching, experimenting and fitting models.
python has a ton of very useful libraries such as spacy, nltk and sklearn that makes exploration very easy, especially in within a jupyter notebook.

When running the code in production, If performance is a consideration, we implement only the prediction phase in java.

java is more suited for production, has great support for packaging, tests, deployment.