返回列表时Spring期望'：'而不是't'错误？答案

【问题标题】：Spring Expected ':' instead of 't' error when returning List?返回列表时Spring期望'：'而不是't'错误？
【发布时间】：2016-10-17 08:33:52
【问题描述】：

我有一个简单的RequestMapping 方法，它返回Users 的列表，Users 模型与HolidayDates 有一个ONE TO MANY 关系...我只是在玩它，所以我选择了假期日期作为关系（他们去度假的日期列表）。

所以ONE 用户可以拥有MANY 相关的Dates。

用户模型：

@Entity
@Table(name="user")
public class User {

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name="userId")
    private int userId;

    @Column(name="about")
    private String about;

    // Maybe change to fetchtype eager
    @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, mappedBy = "holidayDates")
    private Set<HolidayDates> holidayDates;
    public void setHolidayDates(Set<HolidayDates> holidayDates) {
        this.holidayDates = holidayDates;
    }
    public Set<HolidayDates> getHolidayDates() {
        return holidayDates;
    }
    ...Other setters and getters

HolidayDate 模型：

@Entity
@Table(name="holiday_dates")
public class HolidayDates {
//
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name="holidayId")
    private int holidayId;

    @Column(name="start_date")
    private String startDate;

    @Column(name="end_date" )
    private String endDate;

    @ManyToOne
    @JoinColumn(name = "userId")
    private User user;

当我找到所有用户及其相关的假期日期时，使用以下代码：

@RequestMapping(value="{name}", method=RequestMethod.GET)
public @ResponseBody List<User> user(@PathVariable String name) {
    List<User> user = userService.findAll();
    // Simply implementing List<User> findAll(); from userService auto wired field

    return user;
}

userService 有一个@autowired 字段到userDao，它只是扩展了JPA 存储库：

public interface UserDao extends JpaRepository <User, Integer> {

现在，当我在控制器上运行GET 请求时，它会返回以下响应：

Expected ':' instead of 't'

以及 fastxml.jackson 错误的大长堆栈跟踪：

[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
        at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]

spring 不会处理所有这些jpa/model 到json 的转换吗？

【问题讨论】：

User @Column(name="userId`") 似乎有错字（注意userId 后面的`）。
我修复了这个问题，这实际上不在我的代码中！不确定复制粘贴到 SO 时发生了什么。我已经解决了@ElliottFrisch 的问题
应该@Table(name="holiday_daes") 是@Table(name="holiday_dates")？
另一个错字，已修复。 @ElliottFrisch
看起来正在进行无限递归...您可能希望在HolidayDates 中将@JsonIgnore 添加到getUser... 或从HolidayDates 一起删除user ，除非你需要它在那里......

标签： java json spring jackson

【解决方案1】：

由于User 指代HolidayDates 和HolidayDates 指代User，您在序列化期间进行了无限递归。您可以通过在HolidayDates 中将@JsonIgnore 添加到getUser 来阻止它。

【讨论】：

奇怪的是它没有在堆栈跟踪中显示这个......但我觉得堆栈跟踪太长而无法放入我的终端窗口，因此它没有显示。
但是当你这样做时，json 不包含数据？
@jny @JsonIgnore 注释只是忽略了关系的一侧，从而破坏了链条。此标记注释指示带注释的方法或字段将被基于自省的序列化和反序列化功能忽略。也就是说，它不应被视为“getter”、“setter”或“creator”。所以结果将是不完整的，这意味着只会获取父类属性，而不是相关的子类属性。要克服这种情况，请使用 @JsonManagedReference 和 @JsonBackReference

【解决方案2】：

@JsonManagedReference
private Set<HolidayDates> holidayDates;

和

@JsonBackReference
private User user;

【讨论】：

虽然这可能会回答问题，但最好添加一些关于此答案如何有助于解决问题的描述。请阅读How do I write a good answer了解更多信息。

【解决方案3】：

这个问题是因为实体类之间的无限递归，旧版本使用@JsonIgnore，新版本使用此代码。

 @OneToMany(
            mappedBy = "queue_group",fetch = FetchType.LAZY,
            cascade = CascadeType.ALL
        )
    @JsonManagedReference
    private Set<Queue> queues;

@ManyToOne(cascade=CascadeType.ALL)
        @JoinColumn(name = "qid")
       // @JsonIgnore
        @JsonBackReference
        private Queue_group queue_group;

【讨论】：

【解决方案4】：

同样的错误，但在我的情况下，因为我缺少实现默认构造函数。

public User() {}

【讨论】：

【解决方案5】：

虽然我同意这个问题的正确答案是 jny 接受的答案，但我在 Spring Boot 中安装了一个错误的 Jackson objectMapper 配置，我得到了完全相同的问题，由于某种原因，而不是修复日期序列化，搞砸了一个完全不同的类的序列化。我删除了以下代码，事情又开始工作了。把这个放在这里以防有人遇到同样的问题

@Bean
@Primary
public ObjectMapper objectMapper(Jackson2ObjectMapperBuilder builder) {
    ObjectMapper objectMapper = builder.createXmlMapper(false).build();
    objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
//  objectMapper.configure(SerializationFeature.WRITE_DATE_TIMESTAMPS_AS_NANOSECONDS, false);
    return objectMapper;
}

【讨论】：

【解决方案6】：

在您的用户模型中添加 @JsonManagedReference 并为 HolidayDates 模型添加 @JsonBackReference

用户模型：

@OneToMany
 @JsonManagedReference
 private Set<HolidayDates> holidayDates;

HolidayDate 模型：

 @ManyToOne
    @JsonBackReference
    private User user;

【讨论】：

【解决方案7】：

这是一个非常古老的帖子，但我遇到了类似的问题，即反向引用应用程序正在循环，并且我遇到了类似的错误。我希望包含的依赖对象保留在实体的任一侧。 @JsonManagedReference、@JsonBackReference 和 @JsonIdentityInfo 没有帮助。你可以改用@JsonIgnoreProperties。

在课堂上User

@JsonIgnoreProperties(value = {"user"})
private Set<HolidayDates> holidayDates;

在HolidayDates

@JsonIgnoreProperties(value = {"holidayDates"})
private User user;

这种方式对我很有效。这篇http://springquay.blogspot.com/2016/01/new-approach-to-solve-json-recursive.html?m=1 的帖子解释了上述每个注释的优缺点。

【讨论】：