Hibernate：通过反射持久属性访问字段[private java.lang.Integer]时出错 [英] Hibernate: Error accessing field [private java.lang.Integer ] by reflection for persistent property

问题描述

当我尝试获取实体属性时，我有一个奇怪的问题：

I have strange issue when I try to get entities property:

Hibernate: 
    select
        tarifklsk0_.ID as ID1_12_0_,
        tarifklsk0_.FK_TARIF as FK_TARIF2_12_0_,
        tarifservp1_.FK_TARIF as FK_TARIF2_11_1_,
        tarifservp1_.ID as ID1_11_1_,
        tarifservp1_.ID as ID1_11_2_,
        tarifservp1_.FK_TARIF as FK_TARIF2_11_2_,
        tarifservp1_.N1 as N3_11_2_ 
    from
        TR.TARIFXKLSK tarifklsk0_ 
    left outer join
        TR.TARIF_SERV_PROP tarifservp1_ 
            on tarifklsk0_.FK_TARIF=tarifservp1_.FK_TARIF 
    where
        tarifklsk0_.ID=?
Jun 13, 2016 7:38:26 AM org.hibernate.event.internal.DefaultLoadEventListener doOnLoad
INFO: HHH000327: Error performing load command : org.hibernate.property.access.spi.PropertyAccessException: Error accessing field [private java.lang.Integer TarifKlsk.fkTarif] by reflection for persistent property [TarifKlsk#fkTarif] : 1027303
Exception in thread "main" org.hibernate.property.access.spi.PropertyAccessException: Error accessing field [private java.lang.Integer TarifKlsk.fkTarif] by reflection for persistent property [TarifKlsk#fkTarif] : 1027303
    at org.hibernate.property.access.spi.GetterFieldImpl.get(GetterFieldImpl.java:43)
    ....skipped...
Caused by: java.lang.IllegalArgumentException: Can not set java.lang.Integer field TarifKlsk.fkTarif to java.lang.Integer
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:167)
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:171)       

我的实体：

TarifKlsk

import java.util.HashSet;
import java.util.Set;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToMany;
import javax.persistence.Table;

import org.hibernate.annotations.BatchSize;

@SuppressWarnings("serial")
@Entity
@Table(name = "TARIFXKLSK", schema="TR")
public class TarifKlsk implements java.io.Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "ID", updatable = false, nullable = false)
    private Integer id;

    @OneToMany(fetch = FetchType.EAGER)
    @JoinColumn(name="FK_TARIF", referencedColumnName="FK_TARIF")
    @BatchSize(size = 50)
    private Set<TarifServProp> tarifservprop = new HashSet<TarifServProp>(0);

    @Column(name = "FK_TARIF", updatable = false, nullable = false)
    private Integer fkTarif;

    public Integer getId() {
        return id;
    }

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

    public Set<TarifServProp> getTarifservprop() {
        return tarifservprop;
    }

    public void setTarifservprop(Set<TarifServProp> tarifservprop) {
        this.tarifservprop = tarifservprop;
    }

    public Integer getFkTarif() {
        return fkTarif;
    }

    public void setFkTarif(Integer fkTarif) {
        this.fkTarif = fkTarif;
    }

}

TarifServProp

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@SuppressWarnings("serial")
@Entity
@Table(name = "TARIF_SERV_PROP", schema="TR")
public class TarifServProp implements java.io.Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "ID", updatable = false, nullable = false)
    private Integer id;

    @Column(name = "FK_TARIF", updatable = false, nullable = false)
    private Integer fkTarif;

    public Integer getId() {
        return id;
    }

    @Column(name = "N1", updatable = false, nullable = false)
    private Integer n1;

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

    public Integer getFkTarif() {
        return fkTarif;
    }

    public void setFkTarif(Integer fkTarif) {
        this.fkTarif = fkTarif;
    }

    public Integer getN1() {
        return n1;
    }

    public void setN1(Integer n1) {
        this.n1 = n1;
    }

}

我的测试模块：

    public static void main(String[] args) {
        SessionFactory sf = HibernateUtil.getSessionFactory();
        Session sess = sf.openSession();
        sess.beginTransaction();

        TarifKlsk k2=sess.get(TarifKlsk.class, 1027303);
        for (TarifServProp t : k2.getTarifservprop()) {
             System.out.println("Tar="+t.getN1());
        }

        System.out.println("End init");

我做错了什么？我检查了这些实体的所有字段，并且所有字段都正确命名....

What am I doing wrong? I've checked all fields of these entities and all of them named properly....

更新
我的POM.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.journaldev.hibernate</groupId>
    <artifactId>HibernateEHCacheExample</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <description>Hibernate Secondary Level Cache Example using EHCache implementation</description>

    <dependencies>
        <!-- Hibernate Core API -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.1.0.Final</version>
        </dependency>
        <!-- EHCache Core APIs -->
        <!-- http://mvnrepository.com/artifact/net.sf.ehcache/ehcache-core -->
        <dependency>
            <groupId>net.sf.ehcache</groupId>
            <artifactId>ehcache-core</artifactId>
            <version>2.6.11</version>
        </dependency>

        <!-- http://mvnrepository.com/artifact/org.hibernate/hibernate-ehcache -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-ehcache</artifactId>
            <version>5.2.0.Final</version>
        </dependency>

        <!-- EHCache uses slf4j for logging -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-simple</artifactId>
            <version>1.7.5</version>
        </dependency>
    </dependencies>
</project>

Upd2

我发现我的子实体不包含fk_tarif对应于来自master的fk_tarif的记录...但我认为没关系，为什么错误存在？

I've found out that my child entity doesn't contain records with fk_tarif corresponding to the fk_tarif from master... but I think it doesn't matter, why is error exists?

推荐答案

我正在使用EAP7，其中包含Hibernate Core {5.0.9.Final-redhat-1}

I am working with EAP7, which contains Hibernate Core {5.0.9.Final-redhat-1}

我有两个实体：

@Entity
@Data
@EqualsAndHashCode(callSuper = true, doNotUseGetters = true)
@ToString(callSuper = true, doNotUseGetters = true)
public class Keuze extends MainTable {

@NonNull
String naam;

@Tolerate
public Keuze() {
}

}

和

@Entity
@Data
@EqualsAndHashCode(callSuper = true, doNotUseGetters = true, exclude = {"gegeven", "werkJaar", "keuze", "keuzes" })
@ToString(callSuper = true, doNotUseGetters = true, exclude = { "gegeven", "werkJaar", "keuze", "keuzes" })
public class Waarde extends MainTable {

@NonNull
@ManyToOne(optional = false, fetch = FetchType.LAZY)
Gegeven gegeven;

@NonNull
@ManyToOne(optional = false, fetch = FetchType.LAZY)
WerkJaar werkJaar;

String alfanumeriek;

Integer numeriek;

BigDecimal valuta;

@Lob
String tekst;

Boolean polair;

@OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.MERGE)
Keuze keuze;

@ManyToMany(fetch = FetchType.EAGER, cascade = CascadeType.MERGE)
Set<Keuze> keuzes;

@Tolerate
public Waarde() {
}

}

它们都来自这个类：

@MappedSuperclass
@Data
@Cacheable
public abstract class MainTable {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
Long id;

@Version
Long version;

}

在Waarde上调用merge时，会抛出以下错误：

When calling merge upon Waarde, it throws following error:

Caused by: org.hibernate.property.access.spi.PropertyAccessException: Error accessing field [java.lang.Long vo.cjsm.monitoring.data.schema.dynamic.main.MainTable.id] by reflection for persistent property [vo.cjsm.monitoring.data.schema.dynamic.field.Keuze#id] : Keuze(super=MainTable(id=1, version=0), naam=Leesmotivatie)
at org.hibernate.property.access.spi.GetterFieldImpl.get(GetterFieldImpl.java:43)
at org.hibernate.tuple.entity.AbstractEntityTuplizer.getIdentifier(AbstractEntityTuplizer.java:223)
at org.hibernate.persister.entity.AbstractEntityPersister.getIdentifier(AbstractEntityPersister.java:4601)
at org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:148)
at org.hibernate.internal.SessionImpl.fireMerge(SessionImpl.java:850)
at org.hibernate.internal.SessionImpl.merge(SessionImpl.java:832)
at org.hibernate.engine.spi.CascadingActions$6.cascade(CascadingActions.java:260)
at org.hibernate.engine.internal.Cascade.cascadeToOne(Cascade.java:398)
at org.hibernate.engine.internal.Cascade.cascadeAssociation(Cascade.java:323)
at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:162)
at org.hibernate.engine.internal.Cascade.cascadeCollectionElements(Cascade.java:431)
at org.hibernate.engine.internal.Cascade.cascadeCollection(Cascade.java:363)
at org.hibernate.engine.internal.Cascade.cascadeAssociation(Cascade.java:326)
at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:162)
at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:111)
at org.hibernate.event.internal.DefaultMergeEventListener.cascadeOnMerge(DefaultMergeEventListener.java:468)
at org.hibernate.event.internal.DefaultMergeEventListener.entityIsDetached(DefaultMergeEventListener.java:327)
at org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:170)
at org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:69)
at org.hibernate.internal.SessionImpl.fireMerge(SessionImpl.java:840)
at org.hibernate.internal.SessionImpl.merge(SessionImpl.java:822)
at org.hibernate.internal.SessionImpl.merge(SessionImpl.java:827)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.merge(AbstractEntityManagerImpl.java:1161)
... 149 more
Caused by: java.lang.IllegalArgumentException: Can not set java.lang.Long field vo.cjsm.monitoring.data.schema.dynamic.main.MainTable.id to java.lang.String
at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:167)
at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:171)
at sun.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:58)
at sun.reflect.UnsafeObjectFieldAccessorImpl.get(UnsafeObjectFieldAccessorImpl.java:36)
at java.lang.reflect.Field.get(Field.java:393)
at org.hibernate.property.access.spi.GetterFieldImpl.get(GetterFieldImpl.java:39)
... 171 more

按删除Lombok的ToString行并通过覆盖默认值来添加我自己的toString实现，错误消息消失，代码正在恢复！

By removing the ToString line of Lombok and adding my own implementation of toString by overriding the default one, the error message disappeared and the code was working back!

现在实体看起来像这个：

Now the entity looks like this:

@Entity
@Data
@EqualsAndHashCode(callSuper = true, doNotUseGetters = true)
public class Keuze extends MainTable {

@NonNull
String naam;

@Tolerate
public Keuze() {
}

@Override
public String toString() {

    return getId().toString();
}

}

所以不知何故，原因不明toString方法对hibernate如何合并代码有影响...不要问我怎么样:-)它似乎工作正常。我在网上尝试了其他一切而没有运气！

So somehow, for an unknown reason the toString method has effect on how hibernate merges the code... Don't ask me how :-) It just seems to work. I tried everything else on the web with no luck!

希望这对其他人有帮助！

Hope this helps for somebody else!

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