Book Image

Java Data Science Cookbook

By : Rushdi Shams
Book Image

Java Data Science Cookbook

By: Rushdi Shams

Overview of this book

If you are looking to build data science models that are good for production, Java has come to the rescue. With the aid of strong libraries such as MLlib, Weka, DL4j, and more, you can efficiently perform all the data science tasks you need to. This unique book provides modern recipes to solve your common and not-so-common data science-related problems. We start with recipes to help you obtain, clean, index, and search data. Then you will learn a variety of techniques to analyze, learn from, and retrieve information from data. You will also understand how to handle big data, learn deeply from data, and visualize data. Finally, you will work through unique recipes that solve your problems while taking data science to production, writing distributed data science applications, and much more - things that will come in handy at work.
Table of Contents (16 chapters)
Java Data Science Cookbook
About the Author
About the Reviewer
Customer Feedback

Counting word frequency in a string using Java 8

This recipe does not use the Apache Commons Math library to count frequencies of words in a given string; rather it uses core libraries and mechanisms introduced in Java 8.


There are many ways to implement a working example that counts word frequencies, and therefore, the readers are encouraged to look at many implementations of this recipe in Java versions released earlier than 8.

How to do it...

  1. Create a method that takes a string argument. We will be counting frequencies of the words in this string:

            public void getFreqStats(String str){ 
  2. Create a Stream from the given string. In our case, we will be converting the string to lower case and identify words based on a regular expression \W+. The process of converting a string into a stream will be done in parallel:

            Stream<String> stream =   
  3. We will be collecting the words and their frequencies...