Get up to 80 % extra points for free! More info:

Lesson 4 - Java Testing - Unit Tests of Real Applications I

In the previous lesson, Java Testing - Hamcrest, JUnit TestRule and Best Practices, we introduced the Hamcrest library, the rules annotation, and finally we mentioned the best practices for testing in Java. To make sure we don't end with just our calculator's tests, we'll show unit test codes from real applications in the following few lessons. These will be tests of a message analyzer, persistence layer (data storage), and tests of a random token generator. They will help you get a better idea of how such things are tested in practice.

Note: The examples will get more and more complex. Don't worry if you don't understand something in their implementation. You should mainly understand how the tests work, which test verifies which features and how it does it.

Tag analyzer test

The following test verifies that the TagAnalyzer class works correctly. It analyzes a message and searches for hashtags, as you know them from Facebook ("I've overslept again. #mondays").

Let's take a look at the basic structure of the test class with initialization and describe it below.


...End of the preview...
Continue further

You will gain knowledge worth hundreds of thousands for a few crowns

You've come here and that's great! We believe that the first lessons showed you something new and useful
Do you want to continue the course? Go to the premium section.

Buy this course

Buy all currently available lessons with exercise submitting and other features for just $21.60
Current account balance $0
By buying this package, you'll have access to all 12 articles (12 lessons) in this course.

Before buying this article, you have to buy the previous one

This article is licensed: Premium III, by buying this article, you agree with the terms of use.

What will you get from us in the next lessons?
  • Unlimited and permanent access to individual lessons.
  • High quality IT knowledge.
  • Skills to help you get your dream and well-paid job.

Article description

Requested article covers this content:

In this tutorial, we'll analyze the source code of a unit test from a real Java application, where a class representing a message is tested for hashtags.

You gain credits by supporting our network. This is done by sending a helpful amount of money to support the site, or by creating content for the network.

Article has been written for you by David Capka Hartinger
The author is a programmer, who likes web technologies and being the lead/chief article writer at He shares his knowledge with the community and is always looking to improve. He believes that anyone can do what they set their mind to.
Unicorn university David learned IT at the Unicorn University - a prestigious college providing education on IT and economics.