JUnit

JUnit is a test automation framework for the Java programming language.

Lifecycle

Every JUnit test class usually has several test cases. These test cases are subject to the test life cycle. The full JUnit Lifecycle has three major phases:

1. Setup phase- This phase is where the test infrastructure is prepared. Two levels of setup are available. The first type of setup is class-level setup in which a computationally expensive object, such as a database connection, is created and reused, with minimal side effects. Class-level setup is implemented using the @BeforeAll annotation (depending on the version of JUnit you’re using this may also be @BeforeClass). The other type is setup before running each test case, which uses the @BeforeEach annotation.
2. Test execution - This phase is responsible for running the test and verifying the result. The test result will indicate if the test result is a success or a failure. The @Test annotation is used here.
3. Clean up phase - After all posttest executions are performed, the system may need to perform cleanup. Similar to class-level setup, there is a corresponding class-level clean up. The @AfterAll annotation is used to support class-level clean up (again, depending on the version of JUnit you’re using this may also be @AfterClass). The @AfterEach annotation allows for cleanup after test execution.