junit5 - @BeforeAll 是实例化对象所必需的吗？

Question

Is there a difference between creating an instance variable and creating a member variable in a method marked with a @BeforeAll annotation?

Public class Example1Test{

Lift testClass = null;

@BeforeAll
public void init() {
    testClass = new Lift();
}

@Test
...
}

VS

Public class Example2Test{
Lift testClass = new testClass;

@Test
...
}

Answer 1

@BoforeAll is used to make sure that the annotated method should be executed before all the @ParameterizedTest,@Test, @RepeatedTest and @TestFactory methods in the current class. so if you want this method to be run before any other method then yes you have to annotate this.

Answer 2

If object, that is defined and initialized at the same time (like Lift class in your code snippet), has state, it's better to initialize it in @BeforeEach . Object's context is cleared before every test. This makes your test independent from each other.