代码段异常:无法记录响应字段，因为响应正文为空

Question

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);
}

服务：

@Override
public Post createPost(PostEntity postEntity) {
return postFactory.buildPost(postEntityRepository.save(postEntity));
}
//Post is Immutable class here
public Post buildPost(PostEntity entity) {
return new Post.Builder()
.groupId(entity.getGroupEntity().getGroupId())
.postedBy(entity.getPostedBy().getUsername())
.postType(entity.getType())
.postMedia(entity.getPostMedia())
.postId(entity.getPostId())
.build();
}

这是我的模拟Mvc：

@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())
));

这是发布电话：

@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这里的类是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
}
}

和发布实体类：

@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);

但是它仍然不起作用，我面临同样的异常：

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)

Answer 1

问题出在"PostMedia"设置器"PostMedia"和"GroupEntity"上。您需要接受 setters 参数中的字符串并将它们转换为相应的实体。期望资源库的参数作为自定义实体类型会产生问题。

例如：

public class MyModel {

private CustomEnum myEnum;

public CustomEnum getMyEnum() {
return myEnum;
}

public void setMyEnum(String enumName) {
this.myEnum = CustomEnum.valueOf(enumName);
}

}