通过反射休眠不能获得字段值 [英] could not get a field value by reflection hibernate

问题描述

在jpa中更新对象时遇到问题

我有bean用户

  public class User $ 
 $ b @Id 
 @GeneratedValue（strategy = GenerationType.IDENTITY）
 @Column（name =id，unique = true，nullable =假）
私人长ID; 
 @Column（name =name，nullable = false）
私有字符串名称; 
 @OneToMany（fetch = FetchType.EAGER）
 @JoinColumn（name =fk_program_rating）
 private List< Rating> ratingList = new ArrayList< Rating>（）; 
} 
  

和

<$ p
$ b @GeneratedValue（strategy = GenerationType.IDENTITY）
@Column（name =id）public class Rating extends BaseModel {

@Id
@GeneratedValue ，unique = true，nullable = false）
私人长ID;
@ManyToOne（）
@JoinColumn（name =fk_program_rating，nullable = false）
@ForeignKey（name =FK_prog_rate）
@OnDelete（action = OnDeleteAction.CASCADE ）
私人节目节目;
}

当尝试更新时，给我例外：无法获得字段值当表评级有行时发生的反射

$ b

ERROR TransactionInterceptor：434 - 由提交异常覆盖的应用程序异常
com .vodafone.visradio.dataaccess.exception.DataAccessException：org.hibernate.PropertyAccessException：无法通过反射获取字段值getter of com.vodafone.visradio.dataaccess.model.Rating.id

blockquote>

有关此问题的任何帮助

thanks

解决方案

尝试更改映射注释。从 ratingList 中移除 @JoinColumn 注释，并添加 mappedBy 属性：

  @OneToMany（fetch = FetchType.EAGER，mappedBy =user）
 private List< Rating> ratingList = new ArrayList< Rating>（）; 
  

其中 user 是评级与用户具有 @ManyToOne 关联的实体。

I have problem when update object in jpa

i have bean user

public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", unique = true, nullable = false)
    private Long id;
    @Column(name = "name", nullable = false)
    private String name;
    @OneToMany(fetch = FetchType.EAGER)
    @JoinColumn(name = "fk_program_rating")
    private List<Rating> ratingList = new ArrayList<Rating>();
}

and

public class Rating extends BaseModel {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", unique = true, nullable = false)
    private Long id;
    @ManyToOne()
    @JoinColumn(name = "fk_program_rating", nullable = false)
    @ForeignKey(name = "FK_prog_rate")
    @OnDelete(action = OnDeleteAction.CASCADE)
    private Program program;
}

when try to update that give me exception : could not get a field value by reflection that happen when table rating have rows

ERROR TransactionInterceptor:434 - Application exception overridden by commit exception com.vodafone.visradio.dataaccess.exception.DataAccessException: org.hibernate.PropertyAccessException: could not get a field value by reflection getter of com.vodafone.visradio.dataaccess.model.Rating.id

any help about this problem
thanks

解决方案

Try changing the mapping annotations. Remove the @JoinColumn annotation from ratingList and add mappedBy attribute:

@OneToMany(fetch = FetchType.EAGER, mappedBy = "user") 
private List<Rating> ratingList = new ArrayList<Rating>();

where user is the property name in the Rating entity that has a @ManyToOne association with User.

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