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.

Note

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 =   
             Stream.of(str.toLowerCase().split("\\W+")).parallel(); 
   

3. We will be collecting the words and their frequencies...