Here is my Servlet. It gets a String that I've put in a ServletContext in my Listener.

@WebServlet(ADMIN_DISH_PATH)
public class AdminDishServlet extends HttpServlet {
    private String uploadDir;
    private DishService dishService;

    @Override
    public void init() throws ServletException {
        dishService = ServiceManager.getInstance().getDishService();
        ServletContext sc = getServletContext();
        uploadDir = (String) sc.getAttribute(UPLOAD_DIR);
    }
// doGet method 
}

Here is the Test class

@ExtendWith(MockitoExtension.class)
public class AdminDishServletTest {
    @Spy
    AdminDishServlet adminDishServlet;
    private static MockedStatic<ServiceManager> serviceManagerDummy;

    @BeforeAll
    static void setUp() {
        serviceManagerDummy = Mockito.mockStatic(ServiceManager.class);
    }

    @AfterAll
    static  void close() {
        serviceManagerDummy.close();
    }

   

     @Test
        void whenGetReturnDishes() throws ServletException, IOException {
            String uploadDir = "/testDir";
    
            serviceManagerDummy.when(ServiceManager::getInstance).thenReturn(serviceManager);
            when(serviceManager.getDishService()).thenReturn(dishService);
            when(servletContext.getAttribute(UPLOAD_DIR)).thenReturn(uploadDir);
            when(adminDishServlet.getServletContext()).thenReturn(servletContext); // Error happens here
         adminDishServlet.init();
            adminDishServlet.doGet(request, response);
    // Some assertions 
    }
    }

The exception I have

java.lang.IllegalStateException: ServletConfig has not been initialized
    at javax.servlet.GenericServlet.getServletContext(GenericServlet.java:159)

Code from GenericServlet (javax package) where the exception happens

public ServletContext getServletContext() {
    ServletConfig sc = getServletConfig();
    if (sc == null) {
        throw new IllegalStateException(
            lStrings.getString("err.servlet_config_not_initialized"));
    }

    return sc.getServletContext();
}

But how do I pass ServletConfig to Generic Servlet or Initialize it?

CodePudding user response：

Create a mock ServletConfig, mock its getServletContext() method to return your mocked ServletContext, and use the other init method: init(servletConfig). Then you don't need to mock the getServletContext() method of your servlet.