The importance of Java test frameworks in modern, Agile software development simply can't be understated. Of course, software developers tend to like writing code more than they like writing tests, which is why a number of Java testing tools exist on the market today.
Testing itself can span across a wide variety of sectors. In terms of Java test frameworks, we'll focus the discussion on these five areas of application veracity:
Java Unit test frameworks;
behavioral acceptance test frameworks;
Java testing tools for integration APIs;
user interface testing tools; and
stress testing tools.
With these categories in mind, here are five different Java test frameworks that software developers should know.
1. TestNG for unit testing
Most software developers are familiar with JUnit, a Java testing tool that does an excellent job simplifying unit tests written in Java. But TestNG is even better.
TestNG is a combination of the best features from both JUnit and NTest. It provides facilities for group testing, parallel testing and seamless integration with custom reporting and logging tools that make it easier to troubleshoot problems when tests fail.
However, the latest JUnit release implemented many of the features that made TestNG more compelling, so the gap between the two Java unit testing tools has diminished. For my money, I'd stick with TestNG.
2. The Cucumber test framework for Java
Unit testing happens at a very low level in Java programs, thus the term unit. If you want a better idea of how an application behaves to solve a given problem or business case, Cucumber is the right tool to use. Cucumber allows developers to design scenarios that their code must implement. When the code passes the automated test written in Cucumber's Gherkin language, the business case is considered complete.
One of the nice things about Cucumber is it not only helps with applications developed with a focus on behavior-driven development, but the language semantics are so readable that the tests themselves become part of the documentation that pertains to how the system actually works.
3. Java testing tools for SOAP and REST API
The importance of Java test frameworks in the world of modern, Agile software development simply can't be understated.
If you write microservice applications or interact with other systems on the web, you will need access to a Java integration test tool for APIs written in SOAP or REST. For REST-based applications, REST Assured provides an easy-to-learn Java testing framework that allows for quick testing of RESTful URLs, JSON and exceptional cases that can occur when a network fails.
Developers who work with SOAP-based web services can use SoapUI, which provides API testing features akin to those available through REST Assured.
4. Selenium and HtmlUnit as UI test frameworks
Selenium and HtmlUnit are similar -- and popular -- Java test frameworks that validate web applications.
HtmlUnit is written purely in Java and doesn't require an actual web browser like Chrome or Firefox to run. Instead, it runs an internal process that can mimic the behavior of a web application, including the submission of forms, validation of text fields and the execution of JavaScript.
On the other hand, Selenium will use a driver to connect to a web browser like Chrome or Firefox, which some argue provides test results that are more in line with the end user's experience.
The Java test framework HtmlUnit can be used to validate web interfaces.
5. Load testing Java frameworks
The fulfillment of all the functional requirements is one thing, but none of that matters if the applications can't perform under load. To see just how well your application will run when hit with tens, hundreds or even thousands of concurrent requests, Apache JMeter is the right Java testing tool to use.
The JMeter Java test framework provides facilities for load, stress and performance testing, but it can also be used to perform regression tests and a limited set of functional tests, as well. Before any new release goes into production, it should be subject to a rigorous capacity test with Apache JMeter.
