Test-Driven Java Development - Second Edition

The @BeforeClass and @AfterClass annotations

These annotations have the same function in both JUnit and TestNG. Annotated methods will be run before the first test and after the last test, in a current class. The only difference is that TestNG does not require those methods to be static. The reason behind this can be found in the different approaches those two frameworks take when running test methods. JUnit isolates each test into its own instance of the test class, forcing us to have those methods defined as static and, therefore, reusable across all test runs. TestNG, on the other hand, executes all test methods in the context of a single test class instance, eliminating the need for those methods to be static.