@Autowired in @SpringBootTest

Direct Answer

Yes. The Spring TestContext framework can inject beans from the test ApplicationContext into fields, setters, or constructors of the test instance. The test instance is managed by the testing framework with Spring support; it is not an ordinary application bean, and only beans present in that test context can be injected.

Code Example

@SpringBootTest
class OrderServiceIntegrationTest {

    @Autowired
    private OrderService orderService;

    @Autowired
    private OrderRepository orderRepository;

    @MockitoBean
    private PaymentClient paymentClient; // use @MockBean on older Boot

    @Test
    void shouldCreateOrderWithMockedPayment() {
        when(paymentClient.charge(anyDouble())).thenReturn(true);

        var order = orderService.createOrder("laptop", 999.99);

        assertThat(order.getId()).isNotNull();
        verify(paymentClient).charge(999.99);
    }
}

Common Mistakes & Pitfalls

• Assuming any class can be injected: @Autowired can only resolve a bean available in the test context.
• Treating the test as an application bean: TestContext prepares the test instance, but it does not make the class an ordinary application component.
• Confusing @Mock with a bean override: Use @MockitoBean in current Spring, or @MockBean on older Boot, when the mock must replace or provide a bean in the context.