Hibernate error: one-to-one mapping on superclass and subclass

I'm working on a project with Hibernate and MySQL, use annotation for mapping database to data object model. I need to mapping one-to-one between superclass and subclass on ID primary key of their classes. I've modified the sample of this tutorial: http://www.mkyong.com/hibernate/hibernate-one-to-one-relationship-example/

DDL script:

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;

Here is my code after modifying: Stock.java (superclass)

package com.mkyong.common;

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.OneToOne;
import javax.persistence.Table;
import javax.persistence.UniqueConstraint;

import org.hibernate.annotations.Cascade;
import org.hibernate.annotations.CascadeType;

@Entity
@Table(name = "stock", catalog = "mkyong", uniqueConstraints = {
        @UniqueConstraint(columnNames = "STOCK_NAME"),
        @UniqueConstraint(columnNames = "STOCK_CODE") })
public class Stock implements java.io.Serializable {

    private Integer stockId;
    private String stockCode;
    private String stockName;
    private StockDetail stockDetail;

    public Stock() {
    }

    public Stock(String stockCode, String stockName) {
        this.stockCode = stockCode;
        this.stockName = stockName;
    }

    public Stock(String stockCode, String stockName, StockDetail stockDetail) {
        this.stockCode = stockCode;
        this.stockName = stockName;
        this.stockDetail = stockDetail;
    }

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "STOCK_ID", unique = true, nullable = false)
    public Integer getStockId() {
        return this.stockId;
    }

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

    @Column(name = "STOCK_CODE", unique = true, nullable = false, length = 10)
    public String getStockCode() {
        return this.stockCode;
    }

    public void setStockCode(String stockCode) {
        this.stockCode = stockCode;
    }

    @Column(name = "STOCK_NAME", unique = true, nullable = false, length = 20)
    public String getStockName() {
        return this.stockName;
    }

    public void setStockName(String stockName) {
        this.stockName = stockName;
    }

    @OneToOne(fetch = FetchType.LAZY, mappedBy = "stock")
    @Cascade({CascadeType.SAVE_UPDATE})
    public StockDetail getStockDetail() {
        return this.stockDetail;
    }

    public void setStockDetail(StockDetail stockDetail) {
        this.stockDetail = stockDetail;
    }

}

and StockDetail.java (subclass)

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;
    }
}

I've tried to insert some record: 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 Sto开发者_Python百科ckDetail();
        stockDetail.setCompName("Microsoft Company");
        stockDetail.setCompDesc("Blah blah");
        stockDetail.setListedDate(new Date());

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

        session.save(stock);

        session.getTransaction().commit();

    }
}

but an error occurred: Initial SessionFactory creation failed.org.hibernate.AnnotationException: Unable to define/override @Id(s) on a subclass: com.mkyong.common.StockDetail

Could you please help me to resolve this issue? Thank you so much.