Spring Boot忽略了休息控制器中的Jackson注释

Question

So I have an abstract root class Model which has various subclasses. Model is annotated with the following:

@JsonTypeInfo(
        use = JsonTypeInfo.Id.NAME,
        include = JsonTypeInfo.As.PROPERTY,
        property = "model")
@JsonSubTypes({
        @JsonSubTypes.Type(value = LowerBoundThresholdModel.class, name = "LowerBoundThresholdAnomalyDetector"),
        @JsonSubTypes.Type(value = UpperBoundThresholdModel.class, name = "UpperBoundThresholdAnomalyDetector"),
        @JsonSubTypes.Type(value = MovingAverageLowerBoundThresholdModel.class, name = "MovingAverageLowerBoundThresholdAnomalyDetector"),
        @JsonSubTypes.Type(value = MovingAverageUpperBoundThresholdModel.class, name = "MovingAverageUpperBoundThresholdAnomalyDetector"),
        @JsonSubTypes.Type(value = WindowedUpperBoundThresholdModel.class, name = "WindowedLowerBoundThresholdAnomalyDetector"),
        @JsonSubTypes.Type(value = WindowedUpperBoundThresholdModel.class, name = "WindowedUpperBoundThresholdAnomalyDetector")
})
@Entity
@Inheritance(strategy = InheritanceType.JOINED)
@Data
public abstract class Model {

I have a controller annotated with @RestController and a method like this:

@GetMapping("/api/v1/models")
public ResponseEntity<Iterable<Model>> getAllModels() {
    try {
        return ResponseEntity.ok(modelService.getAll());
    } catch (Exception e) {
        return ResponseEntity.status(500).build();
    }
}

I have one test which correctly serializes the Models:

public class JacksonTest extends AbstractApplicationTest {

    @Autowired
    ObjectMapper mapper;

    @Test
    public void shouldSerialiseEvent() throws JsonProcessingException {
        LowerBoundThresholdModel lowerBoundThresholdModel = new LowerBoundThresholdModel();
        lowerBoundThresholdModel.setThreshold(1.0);

        String s = mapper.writeValueAsString(lowerBoundThresholdModel);
        assertThat(s).contains("model").contains("LowerBoundThresholdAnomalyDetector");
    }
}

However when I test the actual RestController it doesn't seem to use the Jackson annotations and doesn't include the class information in the model field as configured:

@Test
public void shouldReturnListOfExistingModels() throws Exception {
    LowerBoundThresholdModel lowerBoundThresholdModel = new LowerBoundThresholdModel();
    lowerBoundThresholdModel.setThreshold(1.0);
    lowerBoundThresholdModelRepository.save(lowerBoundThresholdModel);
    windowedLowerBoundThresholdModelRepository.save(windowedLowerBoundThresholdModel);

    mockMvc.perform(get("/api/v1/models"))
            .andExpect(status().isOk())
            .andExpect(MockMvcResultMatchers.jsonPath("$[0].model", is("LowerBoundThresholdModel")))
            .andExpect(MockMvcResultMatchers.jsonPath("$[0].threshold", is(lowerBoundThresholdModel.getThreshold())))
}

but this test fails with no such JSON path $[0].model

How can I make the controller use the same object mapper so that my JSON output from the controllers is correct?

EDIT: if I remove the line andExpect(MockMvcResultMatchers.jsonPath("$[0].model", is("LowerBoundThresholdModel"))) it passes so its not to do with Iterable not being converted to an indexed array

Answer 1

Iterator does not allow indexed access to a list of items. It just returns the next element. So calling $[0] fails.

By widening the Interface to List it works as expected.

@GetMapping("/api/v1/models")
public ResponseEntity<List<Model>> getAllModels() {
    try {
        return ResponseEntity.ok(modelService.getAll());
    } catch (Exception e) {
        return ResponseEntity.status(500).build();
    }
}