用@MockBean模拟的RestTemplateBuilder为空

我想测试一下 Tasklet 使用 @Autowired RestTemplateBuilder 建立一个 RestTemplate . 这个 执行请求。我想嘲笑这个请求的回应。

@ContextConfiguration(classes = DogTasklet.class )
@RunWith(SpringRunner.class)
public class DogTaskletTest {

    @MockBean
    RestTemplateBuilder restTemplateBuilder;
    private RestTemplate restTemplate = new RestTemplate();

    @Autowired
    private Tasklet sut;

    @Before
    public void setUp() throws Exception {
        given(this.restTemplateBuilder.build()).willReturn(restTemplate);
    }
}

这个 given() 语句抛出NPE,因为 RestTemplateBuilder 实例为 null . 我错过了什么?

null ResponseEntity sut.execute()

@RunWith(SpringRunner.class)
public class DogTaskletTest {

@TestConfiguration
static class TestConfig {

    @Bean
    RestTemplateBuilder restTemplateBuilder() {
        RestTemplateBuilder restTemplateBuilder = mock(RestTemplateBuilder.class);
        RestTemplate restTemplate = mock(RestTemplate.class);
        ResponseEntity responseEntity = mock(ResponseEntity.class);

        given(restTemplateBuilder.build()).willReturn(restTemplate);
        given(restTemplate.execute(any(), any(), any(), any())).willReturn(responseEntity);
        given(responseEntity.getBody()).willReturn("{}");

        return restTemplateBuilder;
    }

    @Bean
    DogTasklet sut() {
        return new DogTasklet("string", restTemplateBuilder());
    }
}
    @Test
    public void execute() throws Exception {
        // when
        sut.execute(stepContribution, chunkContext);
    }
}