返回List时出现Spring预期':'而不是't'错误？

Question

返回List时出现Spring预期':'而不是't'错误？

13

我有一个简单的RequestMapping方法，返回一个Users列表，Users模型与HolidayDates存在一对多的关系...我只是在尝试，所以我选择了假期日期作为关系（他们度假的日期列表）。

因此，ONE个用户可以有MANY个相关的Dates。

User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;

当我使用以下代码查找所有用户及其相关的假期日期时：

@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，指向userDao，它只是扩展了JPA repository：

public interface UserDao extends JpaRepository <User, Integer> {

现在当我在控制器上运行GET请求时，它将返回以下响应：

Expected ':' instead of 't'

除了一个很长的fasterxml.jackson错误堆栈：

[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难道不会处理jpa/model和json之间的转换吗？

- James111

我已经修复了，那实际上不在我的代码中！不确定在将其复制并粘贴到SO时发生了什么。我已经修复了这个问题@ElliottFrisch - James111

另一个打字错误，已修复。@ElliottFrisch - James111

由于您将日期作为字符串使用，我敢打赌您的数据在绑定到JSON对象时出现了问题。 - Jorge Campos

Spring不应该处理将模型转换为JSON吗？@JorgeCampos - James111

1

看起来发生了无限递归... 你可能希望在 HolidayDates 中的 getUser 上添加 @JsonIgnore ... 或者从 HolidayDates 中完全删除 user，除非你需要它在那里。 - jny

显示剩余6条评论

7个回答

2

@JsonManagedReference
private Set<HolidayDates> holidayDates;

并且

@JsonBackReference
private User user;

- Manu

1

虽然这可能回答了问题，但最好添加一些描述，说明这个答案如何帮助解决问题。请阅读如何撰写一个好的答案 以了解更多信息。 - Roshana Pitigala

2

这个问题是由实体类之间的无限递归引起的，对于旧版本，请使用@JsonIgnore，对于新版本，请使用以下代码。

Original Answer翻译成"最初的回答"。

 @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;

- Shubham

1

虽然我同意问题的正确答案是jny接受的答案，但是我遇到了完全相同的问题，原因是在Spring Boot中安装了一个错误的Jackson objectMapper配置，导致除了修复日期序列化之外，还弄乱了另一个完全不同类的序列化。我删除了以下代码，事情又开始正常工作了。只是在这里放置这个问题，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;
}

- triadiktyo

1

我遇到了与你相同的错误，但是在我的情况下，原因是我缺少了默认构造函数的实现。

public User() {}

- Long Nguyen

1

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;

假日日期模型：

 @ManyToOne
    @JsonBackReference
    private User user;

- Tokiniaina Eddy Andriamiandris

0

这是一个非常古老的帖子，但我遇到了类似的问题，其中反向引用应用程序陷入循环，我得到了类似的错误。我想要包含依赖对象以保留实体的两侧。 @JsonManagedReference，@JsonBackReference和@JsonIdentityInfo都没有帮助。您可以使用@JsonIgnoreProperties代替。

在User类中。

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

并且在HolidayDates中

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

这种方法对我非常有效。这篇文章http://springquay.blogspot.com/2016/01/new-approach-to-solve-json-recursive.html?m=1解释了上述每个注释的优缺点。

- Nitin Zadage

网页内容由stack overflow 提供, 点击上面的

可以查看英文原文，
原文链接

- jny · Accepted Answer

42

在序列化期间出现了无限递归，因为User引用了HolidayDates，而HolidayDates又引用了User。您可以通过在HolidayDates中的getUser上添加@JsonIgnore来停止它。

- jny

很奇怪它在堆栈跟踪中没有显示出来...但我有一种感觉，堆栈跟踪太长了，无法适应我的终端窗口，因此没有显示。 - James111

1

但是当你这样做时，JSON 不包括数据？ - user1007522

@JsonIgnore 注解会忽略关系中的一侧，从而打破链条。这个标记注解表示被注释的方法或字段将被内省基于序列化和反序列化功能所忽略。也就是说，它不应该被视为“getter”、“setter”或“creator”。因此，结果将是不完整的，只有父类属性将被获取，而不是相关的子类属性。为了克服这个问题，可以使用 @JsonManagedReference 和 @JsonBackReference。 - Pankaj Shinde