Spring Boot 忽略 Rest Controller 中的 Jackson 注释

Question

所以我有一个抽象根类Model，它有各种子类。模型注释如下：

@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 {

我有一个用@RestController 注释的控制器和一个这样的方法：

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

我有一个正确序列化模型的测试：

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");
    }
}

但是，当我测试实际的 RestController 时，它似乎没有使用 Jackson 注释，也没有按照配置在 model 字段中包含类信息：

@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())))
}

但是这个测试失败了no such JSON path $[0].model

如何让控制器使用相同的对象映射器，以便控制器的 JSON 输出正确？

编辑：如果我删除andExpect(MockMvcResultMatchers.jsonPath("$[0].model", is("LowerBoundThresholdModel"))) 行，它就会通过，所以它与Iterable 没有被转换为索引数组无关

Answer 1

Iterator 不允许对项目列表进行索引访问。它只返回下一个元素。所以调用$[0] 失败。

通过将接口扩大到List，它可以按预期工作。

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