My solutions to coding problems in Java Programming: Build a Recommendation System.
This course is offered at Coursera and is part of the Java Programming and Software Engineering Fundamentals.
This is the fifth and final course of the Specialization, Link to the course.
Some code should be run in a custom Bluej Development Environment made by Duke's University especially for this course. You can get the IDE from the University website here.
Here's my certificate on completing the course.