# @Before VS @BeforeEach VS... reference: ``` +-------------------------------------------------------------------------------------------------------+ ¦ Feature ¦ Junit 4 ¦ Junit 5 ¦ ¦--------------------------------------------------------------------------+--------------+-------------¦ ¦ Execute before all test methods of the class are executed. ¦ @BeforeClass ¦ @BeforeAll ¦ ¦ Used with static method. ¦ ¦ ¦ ¦ For example, This method could contain some initialization code ¦ ¦ ¦ ¦-------------------------------------------------------------------------------------------------------¦ ¦ Execute after all test methods in the current class. ¦ @AfterClass ¦ @AfterAll ¦ ¦ Used with static method. ¦ ¦ ¦ ¦ For example, This method could contain some cleanup code. ¦ ¦ ¦ ¦-------------------------------------------------------------------------------------------------------¦ ¦ Execute before each test method. ¦ @Before ¦ @BeforeEach ¦ ¦ Used with non-static method. ¦ ¦ ¦ ¦ For example, to reinitialize some class attributes used by the methods. ¦ ¦ ¦ ¦-------------------------------------------------------------------------------------------------------¦ ¦ Execute after each test method. ¦ @After ¦ @AfterEach ¦ ¦ Used with non-static method. ¦ ¦ ¦ ¦ For example, to roll back database modifications. ¦ ¦ ¦ +-------------------------------------------------------------------------------------------------------+ ``` ![](/files/-LgDo_AjJuVnVrOQYZSl) The code marked @Before is executed before each test, while @BeforeClass runs once before the entire test fixture. If your test class has ten tests, @Before code will be executed ten times, but @BeforeClass will be executed only once. In general, you use @BeforeClass when multiple tests need to share the same computationally expensive setup code. Establishing a database connection falls into this category. You can move code from @BeforeClass into @Before, but your test run may take longer. Note that the code marked @BeforeClass is run as static initializer, therefore it will run before the class instance of your test fixture is created. In JUnit 5, the tags @BeforeEach and @BeforeAll are the equivalents of @Before and @BeforeClass in JUnit 4. Their names are a bit more indicative of when they run, loosely interpreted: 'before each tests' and 'once before all tests'. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://lin-4.gitbook.io/test/before-vs-beforeeach-vs.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.