获取jUnit：s @BeforeClass的静态字段

Question

Is there any way around the classic problem of

public class SomeClass implements SomeOtherInterface {

  private static SomeInterface some;

  public SomeClass(SomeInterface someInterface) {
    some = someInterface;
  }

  @BeforeClass
  public static void doSomethingWithInterface() {
    System.out.println(someInterface.someValue()); // prints null
  }
}

other than exchanging

System.out.println(someInterface.someValue()); // prints null

with

System.out.println(SomeInterface.someValue());

if someValue is static. The problem is that this is for an framework (extension), and and an implementation of SomeInterface is to be provided by the user.

Answer 1

You set the value of the static member just in the constructor. So before not having at least one object of that class, you won't be able to access someValue() . In Junit the @Before annotation might be useful which is executed before each test and is not static .