Spring SnippetException:无法记录响应字段，因为响应正文为空

这是我的控制器：

 @PostMapping("post")
@PreAuthorize("hasAuthority('WRITE')")
public ResponseEntity<?> createPost(@RequestBody PostEntity postEntity) {
    return new ResponseEntity<>(postService.createPost(postEntity), HttpStatus.CREATED);
}

这是我的mockMvc：

 @BeforeEach
public void setUp(WebApplicationContext webApplicationContext,
                  RestDocumentationContextProvider restDocumentation) {
    this.mockMvc = MockMvcBuilders.webAppContextSetup(webApplicationContext)
            .apply(documentationConfiguration(restDocumentation))
            .alwaysDo(document("{method-name}",
                    preprocessRequest(prettyPrint()), preprocessResponse(prettyPrint())))
            .build();
}

这是我的测试：

this.mockMvc.perform(post("/api/post")
            .contentType(MediaTypes.HAL_JSON)
            .contextPath("/api")
            .content(this.objectMapper.writeValueAsString(postEntity)))
            .andExpect(status().isCreated())
            .andDo(
                    document("{method-name}", preprocessRequest(prettyPrint()),
                            preprocessResponse(prettyPrint()),
                            requestFields(describeCreatePostRequest()),
                            responseFields(describePostEntityResult())
                    ));

以下是邮寄电话：

@Value.Immutable
@JsonSerialize(as = ImmutablePost.class)
@JsonDeserialize(as = ImmutablePost.class)
@JsonInclude(JsonInclude.Include.NON_NULL)
@Relation(value = "post", collectionRelation = "posts")
public interface Post {

    Long getPostId();

    String getPostType();

    String postedBy();

    @Nullable
    PostMedia postMedia();

    Long groupId();

    class Builder extends ImmutablePost.Builder {}
}

PostEntity@Entity类这里是json格式：

 {
        "type" : "text",
        "postedBy" : {
                "username": "sandeep"
        },
        "postMedia" : {
            "mediaType": "text",
            "mediaUrl": "null",
            "content": "Hi this is testing media content",
            "createdAt": 1234,
            "updatedAt": 689
        },
        "groupEntity": {
            "groupId": 4
        }
    }

和后实体类：

@Entity
 @Table(name = "POST")
 @JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
public class PostEntity {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "POST_ID")
private Long postId;

@Column(name = "POST_TYPE")
private String type;

@ManyToOne
@JoinColumn(name = "username", referencedColumnName = "username")
private User postedBy;

@OneToOne(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
@JoinColumn(name = "post_media_id", referencedColumnName = "id")
private PostMedia postMedia;

@ManyToOne(cascade = CascadeType.REMOVE, fetch = FetchType.LAZY)
@JoinColumn(name = "GROUP_ID", referencedColumnName = "GROUP_ID")
private GroupEntity groupEntity;
public PostEntity() {
}

}

我试过了

objectMapper.readValue(objectMapper.writeValueAsString(postEntity), ImmutablePost.class);

还有。但它仍然不起作用，我面临着同样的例外：

org.springframework.restdocs.snippet.SnippetException: Cannot document response fields as the response body is empty

at org.springframework.restdocs.payload.AbstractFieldsSnippet.verifyContent(AbstractFieldsSnippet.java:191)
at org.springframework.restdocs.payload.AbstractFieldsSnippet.createModel(AbstractFieldsSnippet.java:147)
at org.springframework.restdocs.snippet.TemplatedSnippet.document(TemplatedSnippet.java:78)
at org.springframework.restdocs.generate.RestDocumentationGenerator.handle(RestDocumentationGenerator.java:191)

---

问题在于PostMedia设置程序PostMedia和GroupEntity。您需要接受setters参数中的字符串，并将其转换为相应的实体。期望setter的参数作为自定义实体类型是造成问题的原因

例如：

    public class MyModel {
    
        private CustomEnum myEnum;
    
        public CustomEnum getMyEnum() {
            return myEnum;
        }
    
        public void setMyEnum(String enumName) {
            this.myEnum = CustomEnum.valueOf(enumName);
        }
    
   }

---

向其发出POST请求的端点返回了什么？它似乎返回了一个带有空正文的响应，因此对文档的响应中没有任何内容。@Andy Wilkinson实际上API在保存后返回相同的对象。在我的例子中，我将在请求中传递实体，并在对象获得savedIt后返回不可变对象，因为响应似乎没有主体。你能提供一个完整的例子来说明所涉及的一切吗？@AndyWilkinson我已经试着把整个流程放在这里了，如果你还需要其他东西来更新，请告诉我，但事情仍然不完整。例如，没有Post类，因此我无法使用您的代码重现问题。欢迎使用Stack Overflow，并感谢您的贡献。

    public class MyModel {
    
        private CustomEnum myEnum;
    
        public CustomEnum getMyEnum() {
            return myEnum;
        }
    
        public void setMyEnum(String enumName) {
            this.myEnum = CustomEnum.valueOf(enumName);
        }
    
   }