Question

我有一些代码包含下一层：

@JsonRootName("users")
@Entity
@Table(name = "users")
public class User {
   @Id
   @GeneratedValue(strategy= GenerationType.AUTO)
   @Column(name = "id")
   private Integer id;
   @Column(name = "first_name")
   private String firstName;
   @Column(name = "last_name")
   private String lastName;
   @Column(name = "age")
   private Integer age;
   @Column(name = "code")
   private Integer code;

   public Integer getId() {
      return id;
   }

   public void setId(Integer id) {
      this.id = id;
   }

   public String getFirstName() {
      return firstName;
   }

   public void setFirstName(String firstName) {
      this.firstName = firstName;
   }

   public String getLastName() {
      return lastName;
   }

   public void setLastName(String lastName) {
      this.lastName = lastName;
   }

   public Integer getAge() {
      return age;
   }

   public void setAge(Integer age) {
      this.age = age;
   }

   public Integer getCode() {
      return code;
   }

   public void setCode(Integer code) {
      this.code = code;
   }
}

public class UsersDao {
   @Autowired
   public SessionFactory sessionFactory;

   public Session session() {
      return sessionFactory.getCurrentSession();
   }

   public List<User> findAll(){
      Query<User> query = session().createQuery("from User", User.class);
      return query.list();
   }
}

public class UsersService {
   @Autowired
   public UsersDao usersDao;

   @Transactional(readOnly = true)
   public List<User> findAllUsers(){
      return usersDao.findAll();
   }
}

@Controller
@RequestMapping("/users")
public class UsersController {
   @Autowired
   UsersService usersService;

   @RequestMapping(value = "/all", produces = {"application/json"})
   @ResponseBody
   public List<User> getAllUsers() {
      return usersService.findAllUsers();
   }
}

当我尝试获取请求localhost：8080 / testreactproject / users / all

时

[{"id":1,"firstName":"John","lastName":"Doe","age":28,"code":916},{"id":2,"firstName":"Jane","lastName":"Doe","age":27,"code":985}]

但我想用根元素

获得下一个json

{"users":[{"id":1,"firstName":"John","lastName":"Doe","age":28,"code":916},{"id":2,"firstName":"Jane","lastName":"Doe","age":27,"code":985}]}

这是对我的pom.xml文件的依赖

<dependency>
        <groupId>org.codehaus.jackson</groupId>
        <artifactId>jackson-mapper-asl</artifactId>
        <version>1.9.10</version>
</dependency>

我知道我应该创建ObjectMapper类的实例，然后再次配置这个实例

mapper.configure(SerializationConfig.Feature.WRAP_ROOT_VALUE, true)

我尝试在控制器类（方法getAllUsers）中添加此代码，但它对我不起作用。我做错了什么？

Answer 1

问题解决了。我为类User（实体层）创建了类包装器，并为包装器绑定了根元素。所以我得到了一个正确的json对象。看起来像是：

<iframe id="myIframe" src="https://stackoverflow.com/questions/45525117/get-iframe-content-by-using-javascript#"></iframe>
<script>
  const myFrame = document.getElementById('myIframe');
  myFrame.addEventListener('load', (evt) => {
    console.log(evt.target === myFrame);
    console.log(evt.target);
  });
</script>

无法使用命名的根元素生成json

1 个答案: