在休眠中使用@Transient 时出现异常答案

【问题标题】：Exception when using @Transient in hibernate在休眠中使用@Transient 时出现异常
【发布时间】：2018-11-28 01:57:09
【问题描述】：

我想在 bean 类中有一个 Extra 变量，以便我在 String 日期这个额外的成员变量上使用 @Transient。正如我在其他教程中所写的那样

额外的列如下

package com.rasvek.cg.entity;
// Generated May 14, 2018 11:39:07 PM by Hibernate Tools 5.1.7.Final

import static javax.persistence.GenerationType.IDENTITY;

import java.util.Date;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.persistence.Transient;

import com.fasterxml.jackson.annotation.JsonIgnore;

/**
 * FeeTermDates generated by hbm2java
 */
@Entity
@Table(name = "fee_term_dates", catalog = "campus_guru_01")
public class FeeTermDates implements java.io.Serializable {

    private int tdmId;
    private FeeTerms feeTerms;
    @Transient
    private String date;

    @Temporal(TemporalType.DATE)
    private Date termDate;
    public FeeTermDates() {
    }

    public FeeTermDates(int tdmId, FeeTerms feeTerms) {
        this.tdmId = tdmId;
        this.feeTerms = feeTerms;
    }

    public FeeTermDates(int tdmId, FeeTerms feeTerms, String date) {
        this.tdmId = tdmId;
        this.feeTerms = feeTerms;
        this.date = date;
    }

    @Id
    @GeneratedValue(strategy = IDENTITY)
    @Column(name = "tdm_id", unique = true, nullable = false)
    public int getTdmId() {
        return this.tdmId;
    }

    public void setTdmId(int tdmId) {
        this.tdmId = tdmId;
    }

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "term_id", nullable = false)
    public FeeTerms getFeeTerms() {
        return this.feeTerms;  
    }  

    public void setFeeTerms(FeeTerms feeTerms) {
        this.feeTerms = feeTerms;
    }

    @Column(name = "date")
    public Date getTermDate() {
        return termDate;
    }

    public void setTermDate(Date termDate) {
        this.termDate = termDate;
    }
    public String getDate() {
        return this.date;
    }

    public void setDate(String date) {
        this.date = date;
    }
}

但我在例外情况下感到高兴

org.hibernate.MappingException: Repeated column in mapping for entity: com.rasvek.cg.entity.FeeTermDates column: date (should be mapped with insert="false" update="false")
    at org.hibernate.mapping.PersistentClass.checkColumnDuplication(PersistentClass.java:835)
    at org.hibernate.mapping.PersistentClass.checkPropertyColumnDuplication(PersistentClass.java:853)
    at org.hibernate.mapping.PersistentClass.checkColumnDuplication(PersistentClass.java:875)
    at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:607)
    at org.hibernate.mapping.RootClass.validate(RootClass.java:265)
    at org.hibernate.boot.internal.MetadataImpl.validate(MetadataImpl.java:329)
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:459)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:710)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
    at org.springframework.orm.hibernate5.LocalSessionFactoryBean.buildSessionFactory(LocalSessionFactoryBean.java:511)
    at org.springframework.orm.hibernate5.LocalSessionFactoryBean.afterPropertiesSet(LocalSessionFactoryBean.java:495)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1688)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1626)
    ... 77 more

我的 bean 类中是否有任何错误有额外的成员变量？

或

还有其他方法吗？谁能帮帮我？

【问题讨论】：

标签： java hibernate jpa jakarta-ee transient

【解决方案1】：

来自JSR 338: JavaTM Persistence API, Version 2.1：

2.3.1 默认访问类型

当注解用于定义默认访问类型时，在任一持久字段上放置映射注释或实体类的持久属性指定访问类型分别是基于字段或基于属性的访问。

当使用基于属性的访问时，对象/关系映射实体类的注解注解 getter 属性 accessors[7]，持久化提供者运行时访问持久化通过属性访问器方法进行状态。所有属性未注释 Transient 注释是持久的。

因此，您需要将 @Transient 放在 getter 上。

【讨论】：