Spring REST，JSON“无法处理托管/返回引用'defaultReference'” 415不支持的媒体类型 [英] Spring REST, JSON "Can not handle managed/back reference 'defaultReference'" 415 Unsupported Media Type
问题描述
我试图从AngularJS前端使用 http：// localhost：9095 / translators 进行发布
我可以做一个GET，其响应如下所示：
[{ 用户id：1， 名字： 约翰， 姓氏： Doe的， EMAILID： john.doe@inc.com， 语言： [{ languageId：1， 语言代码： GB， 源极：真}]， 翻译：[{ translationId：3 的SourceID：1， sourceText： 你好， targetId：null，targetText：null，translationStatus：DUE}]，userType：TRANSLATOR}
发布下面的json时，我收到了错误响应
POST数据：
{
姓：zen，
姓：cv，
emailId：email，
userType：TRANSLATOR，
语言：[{languageId：1，lang uageCode：gb，source：true}]
}
{
时间戳：1422389312497
状态：415
错误：不支持的媒体类型
例外：org.springframework.web.HttpMediaTypeNotSupportedException
消息：不支持内容类型'application / json'
路径：/ translators
}
我确保我的控制器具有正确的Mediatype注释。
@RestController
@RequestMapping（/ translators）
public class TranslatorController {
@Autowired
private UserRepository库;
@RequestMapping（method = RequestMethod.GET）
public List findUsers（）{
return repository.findAll（）;
}
@RequestMapping（value =/ {userId}，method = RequestMethod.GET）
public User findUser（@PathVariable Long userId）{
return repository.findOne（用户id）;
$ b @RequestMapping（method = RequestMethod.POST，consumes = MediaType.APPLICATION_JSON_VALUE，产生= MediaType.APPLICATION_JSON_VALUE）
public用户addTranslator（@RequestBody用户用户）{
//translation.setTranslationId(null）;
返回repository.saveAndFlush（user）;
}
@RequestMapping（value =/ {translatorId}，method = RequestMethod.PUT）
public User updateTranslation（@RequestBody User updatedUser，@PathVariable Long userId）{
//updatedTranslation.setTranslationId(translationId）;
返回repository.saveAndFlush（updatedUser）;
}
@RequestMapping（value =/ {translatorId}，method = RequestMethod.DELETE）
public void deleteTranslation（@PathVariable Long translationId）{
repository .delete（translationId）;
$ b经过一些研究并通过查看日志输出，意识到这是一个误导性的错误信息，问题实际上是在序列化/反序列化Json的过程中发生的问题
在日志文件中，我发现
2015-01-27 21：08：32.488警告15152 --- [nio-9095-exec-1]
.cjMappingJackson2HttpMessageConverter：未能评估
反序列化类型为[简单类型，类用户]：
java.lang.IllegalArgumentException：无法处理托管/返回
引用'defaultReference'：返回引用类型（java.util.List）not
兼容托管类型（User）
这里是我的类User和class Translation（getter，setter，constructor等省略
pre code $ @ $实例
@Table（name =users）
public class User {
@Id
@GeneratedValue（strategy = GenerationType.AUTO）
@Column （name =user_id）
private long userId;
@Column（name =first_name）
private String firstName;
@Column（name =last_name）
private String lastName;
@Column（name =email_id）
private String emailId;
$ b @ManyToMany
@JoinTable（name =languages_users，joinColumns = {@JoinColumn（name =user_id）}，
inverseJoinColumns = {@JoinColumn（name = lang_id）}）
@JsonManagedReference
private List< Language> languages = new ArrayList< Language>（）;
@OneToMany（mappedBy =translator，fetch = FetchType.EAGER）
@JsonManagedReference
private List< Translation>译文;
@Enumerated（EnumType.STRING）
private UserType userType;
}
@Entity
@Table（name =translations）
public class Translation {
@Id
@GeneratedValue（strategy = GenerationType.IDENTITY）
@Column（name =translation_id）
private long translationId;
@Column（name =source_lang_id）
private long sourceId;
@Column（name =source_text）
private String sourceText;
@Column（name =target_lang_id）
private long targetId;
@Column（name =target_text）
private String targetText;
@Enumerated（EnumType.STRING）
@Column（name =status）
私有TranslationStatus translationStatus;
@ManyToOne
@JoinColumn（name =translator_id）
@JsonBackReference
私人用户翻译器;
$ / code>
我的问题是：如何正确设置JsonManagedReference和JsonBackReference以上实体？我确实阅读了文档，并且根据错误消息我无法弄清楚这里有什么问题
我解决了JsonManagedReference和JsonBackReference并将其替换为JsonIdentityInfo
I am trying to POST to http://localhost:9095/translators from an AngularJS front-end using Spring boot/Spring RestController backend.
I can do a GET and the response is like following:
[{"userId":1,"firstName":"John","lastName":"Doe","emailId":"john.doe@inc.com","languages":[{"languageId":1,"languageCode":"gb","source":true}],"translations":[{"translationId":3,"sourceId":1,"sourceText":"Hello","targetId":null,"targetText":null,"translationStatus":"DUE"}],"userType":"TRANSLATOR"}
When I post the below json, I get the error response
POST data:
{
firstName: "zen",
lastName: "cv",
emailId: "email",
userType: "TRANSLATOR",
languages : [{languageId:1,languageCode:"gb",source:true}]
}
Error:
{
timestamp: 1422389312497
status: 415
error: "Unsupported Media Type"
exception: "org.springframework.web.HttpMediaTypeNotSupportedException"
message: "Content type 'application/json' not supported"
path: "/translators"
}
I have made sure that my controller has correct Mediatype annotation.
@RestController
@RequestMapping("/translators")
public class TranslatorController {
@Autowired
private UserRepository repository;
@RequestMapping(method = RequestMethod.GET)
public List findUsers() {
return repository.findAll();
}
@RequestMapping(value = "/{userId}", method = RequestMethod.GET)
public User findUser(@PathVariable Long userId) {
return repository.findOne(userId);
}
@RequestMapping(method = RequestMethod.POST, consumes = MediaType.APPLICATION_JSON_VALUE, produces = MediaType.APPLICATION_JSON_VALUE)
public User addTranslator(@RequestBody User user) {
//translation.setTranslationId(null);
return repository.saveAndFlush(user);
}
@RequestMapping(value = "/{translatorId}", method = RequestMethod.PUT)
public User updateTranslation(@RequestBody User updatedUser, @PathVariable Long userId) {
//updatedTranslation.setTranslationId(translationId);
return repository.saveAndFlush(updatedUser);
}
@RequestMapping(value = "/{translatorId}", method = RequestMethod.DELETE)
public void deleteTranslation(@PathVariable Long translationId) {
repository.delete(translationId);
}
}
After some research and also by seeing log output, I realize that this is a misleading error message and the problem is in fact happening while serializing/deserializing Json
In log file, I find
2015-01-27 21:08:32.488 WARN 15152 --- [nio-9095-exec-1] .c.j.MappingJackson2HttpMessageConverter : Failed to evaluate deserialization for type [simple type, class User]: java.lang.IllegalArgumentException: Can not handle managed/back reference 'defaultReference': back reference type (java.util.List) not compatible with managed type (User)
Here is my class User and class Translation (getter, setter, constructor etc. omitted for brevity)
@Entity
@Table(name = "users")
public class User {
@Id
@GeneratedValue(strategy= GenerationType.AUTO)
@Column(name = "user_id")
private long userId;
@Column(name = "first_name")
private String firstName;
@Column(name = "last_name")
private String lastName;
@Column(name = "email_id")
private String emailId;
@ManyToMany
@JoinTable(name = "languages_users", joinColumns = { @JoinColumn(name = "user_id")},
inverseJoinColumns = {@JoinColumn(name = "lang_id")})
@JsonManagedReference
private List<Language> languages = new ArrayList<Language>();
@OneToMany(mappedBy = "translator", fetch = FetchType.EAGER)
@JsonManagedReference
private List<Translation> translations;
@Enumerated(EnumType.STRING)
private UserType userType;
}
@Entity
@Table(name = "translations")
public class Translation {
@Id
@GeneratedValue(strategy= GenerationType.IDENTITY)
@Column(name = "translation_id")
private Long translationId;
@Column(name = "source_lang_id")
private Long sourceId;
@Column(name = "source_text")
private String sourceText;
@Column(name = "target_lang_id")
private Long targetId;
@Column(name = "target_text")
private String targetText;
@Enumerated(EnumType.STRING)
@Column(name = "status")
private TranslationStatus translationStatus;
@ManyToOne
@JoinColumn(name = "translator_id")
@JsonBackReference
private User translator;
}
My question is this: How can I correctly set JsonManagedReference and JsonBackReference for the above entities? I did read the doc. and I cannot figure out what is wrong here based on the error message
I got it solved by getting rid of JsonManagedReference and JsonBackReference and replacing it with JsonIdentityInfo
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