Hibernate 休眠错误：超类和子类上的一对一映射

我正在使用Hibernate和MySQL进行一个项目，使用注释将数据库映射到数据对象模型。我需要在类的ID主键上的超类和子类之间进行一对一的映射。我修改了本教程的示例：

DDL脚本：

CREATE DATABASE IF NOT EXISTS mkyong;
USE mkyong;

--
-- Definition of table `stock`
--

DROP TABLE IF EXISTS `stock`;
CREATE TABLE `stock` (
  `STOCK_ID` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `STOCK_CODE` varchar(10) NOT NULL,
  `STOCK_NAME` varchar(20) NOT NULL,
  PRIMARY KEY (`STOCK_ID`) USING BTREE,
  UNIQUE KEY `UNI_STOCK_NAME` (`STOCK_NAME`),
  UNIQUE KEY `UNI_STOCK_ID` (`STOCK_CODE`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=34 DEFAULT CHARSET=utf8;

--
-- Definition of table `stock_detail`
--
DROP TABLE IF EXISTS `mkyong`.`stock_detail`;
CREATE TABLE  `mkyong`.`stock_detail` (
  `STOCK_ID` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `COMP_NAME` varchar(100) NOT NULL,
  `COMP_DESC` varchar(255) DEFAULT NULL,
  `REMARK` varchar(255) DEFAULT NULL,
  `LISTED_DATE` date NOT NULL,
  PRIMARY KEY (`STOCK_ID`) USING BTREE,
  CONSTRAINT `FK_STOCK_ID` FOREIGN KEY (`STOCK_ID`) REFERENCES `stock` (`STOCK_ID`)
) ENGINE=InnoDB AUTO_INCREMENT=86 DEFAULT CHARSET=utf8;

以下是我修改后的代码： Stock.java（超类）

和StockDetail.java（子类）

我尝试插入一些记录： MainApplication.java

package com.mkyong.common;

import java.util.Date;
import org.hibernate.Session;
import com.mkyong.persistence.HibernateUtil;

public class App {

    public static void main(String[] args) {
        System.out.println("Maven + Hibernate One-to-One example + MySQL");
        Session session = HibernateUtil.getSessionFactory().openSession();

        session.beginTransaction();

        Stock stock = new Stock();

        stock.setStockCode("9588");
        stock.setStockName("MSFT");

        StockDetail stockDetail = new StockDetail();
        stockDetail.setCompName("Microsoft Company");
        stockDetail.setCompDesc("Blah blah");
        stockDetail.setListedDate(new Date());

        stock.setStockDetail(stockDetail);
        stockDetail.setStock(stock);

        session.save(stock);

        session.getTransaction().commit();

    }
}

但出现了一个错误： 初始SessionFactory创建失败。org.hibernate.AnnotationException:无法在子类com.mkyong.common.StockDetail上定义/覆盖@Id

---

你能帮我解决这个问题吗？非常感谢。

我认为您需要定义一个AbstractStock类，并使Stock和StockDetail都继承自AbstractStock。我不认为在hibernate中不使用超类就可以做任何事情。我认为需要定义一个AbstractStock类，并使Stock和StockDetail都继承自AbstractStock。我不认为在hibernate中不使用超类就可以做任何事情。

package com.mkyong.common;

// Generated Jan 19, 2010 6:46:22 PM by Hibernate Tools 3.2.5.Beta

import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToOne;
import javax.persistence.PrimaryKeyJoinColumn;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import org.hibernate.annotations.GenericGenerator;
import org.hibernate.annotations.Parameter;

/**
 * StockDetail generated by hbm2java
 */
@Entity
@Table(name = "stock_detail", catalog = "mkyong")
public class StockDetail extends Stock implements java.io.Serializable {

    private Integer stockId;
    private Stock stock;
    private String compName;
    private String compDesc;
    private String remark;
    private Date listedDate;

    public StockDetail() {
    }

    public StockDetail(Stock stock, String compName, Date listedDate) {
        this.stock = stock;
        this.compName = compName;
        this.listedDate = listedDate;
    }

    public StockDetail(Stock stock, String compName, String compDesc,
            String remark, Date listedDate) {
        this.stock = stock;
        this.compName = compName;
        this.compDesc = compDesc;
        this.remark = remark;
        this.listedDate = listedDate;
    }

    @GenericGenerator(name = "generator", strategy = "foreign", parameters = @Parameter(name = "property", value = "stock"))
    @Id
    @GeneratedValue(generator = "generator")
    @Column(name = "STOCK_ID", unique = true, nullable = false)
    public Integer getStockId() {
        return this.stockId;
    }

    public void setStockId(Integer stockId) {
        this.stockId = stockId;
    }

    @OneToOne(fetch = FetchType.LAZY)
    @PrimaryKeyJoinColumn
    public Stock getStock() {
        return this.stock;
    }

    public void setStock(Stock stock) {
        this.stock = stock;
    }

    @Column(name = "COMP_NAME", nullable = false, length = 100)
    public String getCompName() {
        return this.compName;
    }

    public void setCompName(String compName) {
        this.compName = compName;
    }

    @Column(name = "COMP_DESC")
    public String getCompDesc() {
        return this.compDesc;
    }

    public void setCompDesc(String compDesc) {
        this.compDesc = compDesc;
    }

    @Column(name = "REMARK")
    public String getRemark() {
        return this.remark;
    }

    public void setRemark(String remark) {
        this.remark = remark;
    }

    @Temporal(TemporalType.DATE)
    @Column(name = "LISTED_DATE", nullable = false, length = 10)
    public Date getListedDate() {
        return this.listedDate;
    }

    public void setListedDate(Date listedDate) {
        this.listedDate = listedDate;
    }
}

package com.mkyong.common;

import java.util.Date;
import org.hibernate.Session;
import com.mkyong.persistence.HibernateUtil;

public class App {

    public static void main(String[] args) {
        System.out.println("Maven + Hibernate One-to-One example + MySQL");
        Session session = HibernateUtil.getSessionFactory().openSession();

        session.beginTransaction();

        Stock stock = new Stock();

        stock.setStockCode("9588");
        stock.setStockName("MSFT");

        StockDetail stockDetail = new StockDetail();
        stockDetail.setCompName("Microsoft Company");
        stockDetail.setCompDesc("Blah blah");
        stockDetail.setListedDate(new Date());

        stock.setStockDetail(stockDetail);
        stockDetail.setStock(stock);

        session.save(stock);

        session.getTransaction().commit();

    }
}