Hibernate中配置复合主键映射

1.通常将复合主键单独建一个类；
2.复合主键类必须实现java.io.Serializable接口，必须重写hashCode和equals方法；
3.在映射文件中配置复合主键：
        
            
            
        


hibernate.cfg.xml:

 

xml version='1.0' encoding='UTF-8'?>

          "-//Hibernate/Hibernate Configuration DTD 3.0//EN"

     "">

  

<hibernate-configuration>

  

<session-factory>

    <property name="connection.username">scottproperty>

    <property name="connection.url">

        jdbc:oracle:thin:@127.0.0.1:1521:MGC

    property>

    <property name="dialect">

        org.hibernate.dialect.Oracle9Dialect

    property>

    <property name="myeclipse.connection.profile">MGCproperty>

    <property name="connection.password">tigerproperty>

    <property name="connection.driver_class">

        oracle.jdbc.driver.OracleDriver

    property>

  

    <property name="show_sql">trueproperty>

    <mapping

        resource="cn/edu/ahau/mgc/hibernate/pojo/YearPeriod.hbm.xml" />

  

session-factory>

  

hibernate-configuration>

YearPeriodPK.java:

 

package cn.edu.ahau.mgc.hibernate.pojo;

  

import java.io.Serializable;

  

public class YearPeriodPK implements Serializable{

  

    private int year;

    private int period;

  

    public int getYear() {

        return year;

    }

  

    public void setYear(int year) {

        this.year = year;

    }

  

    public int getPeriod() {

        return period;

    }

  

    public void setPeriod(int period) {

        this.period = period;

    }

  

    @Override

    public int hashCode() {

        final int prime = 31;

        int result = 1;

        result = prime * result + period;

        result = prime * result + year;

        return result;

    }

  

    @Override

    public boolean equals(Object obj) {

        if (this == obj)

            return true;

        if (obj == null)

            return false;

        if (getClass() != obj.getClass())

            return false;

        final YearPeriodPK other = (YearPeriodPK) obj;

        if (period != other.period)

            return false;

        if (year != other.year)

            return false;

        return true;

    }

}

YearPeriod.java:

 

package cn.edu.ahau.mgc.hibernate.pojo;

  

import java.util.Calendar;

  

public class YearPeriod {

  

    private YearPeriodPK yearPeriodPK;

    private Calendar beginDate;

    private Calendar endDate;

  

    public YearPeriodPK getYearPeriodPK() {

        return yearPeriodPK;

    }

  

    public void setYearPeriodPK(YearPeriodPK yearPeriodPK) {

        this.yearPeriodPK = yearPeriodPK;

    }

  

    public Calendar getBeginDate() {

        return beginDate;

    }

  

    public void setBeginDate(Calendar beginDate) {

        this.beginDate = beginDate;

    }

  

    public Calendar getEndDate() {

        return endDate;

    }

  

    public void setEndDate(Calendar endDate) {

        this.endDate = endDate;

    }

  

}

YearPeriod.hbm.xml:

 

xml version="1.0" encoding="utf-8"?>

"">

<hibernate-mapping>

    <class name="cn.edu.ahau.mgc.hibernate.pojo.YearPeriod" table="YEARPERIOD" schema="SCOTT">

        <composite-id name="YearPeriodPK">

            <key-property name="year" column="YEAR" />

            <key-property name="Period" column="PERIOD" />

        composite-id>

<property name="beginDate" type="java.util.Calendar" column="BEGINDATE" />

<property name="endDate" type="java.util.Calendar" column="ENDDATE" />

    class>

hibernate-mapping>

HibernateSessionFactory.java:

 

package cn.edu.ahau.mgc.hibernate.many2one.factory;

  

import org.hibernate.HibernateException;

import org.hibernate.Session;

import org.hibernate.cfg.Configuration;

  

/**

 * Configures and provides access to Hibernate sessions, tied to the

 * current thread of execution.  Follows the Thread Local Session

 * pattern, see {@link ;}.

 */

public class HibernateSessionFactory {

  

    /** 

     * Location of hibernate.cfg.xml file.

     * Location should be on the classpath as Hibernate uses  

     * #resourceAsStream style lookup for its configuration file. 

     * The default classpath location of the hibernate config file is 

     * in the default package. Use #setConfigFile() to update 

     * the location of the configuration file for the current session.   

     */

    private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";

    private static final ThreadLocal threadLocal = new ThreadLocal();

    private  static Configuration configuration = new Configuration();

    private static org.hibernate.SessionFactory sessionFactory;

    private static String configFile = CONFIG_FILE_LOCATION;

  

    static {

        try {

            configuration.configure(configFile);

            sessionFactory = configuration.buildSessionFactory();

        } catch (Exception e) {

            System.err

                    .println("%%%% Error Creating SessionFactory %%%%");

            e.printStackTrace();

       }

    }

    private HibernateSessionFactory() {

    }

      

    /**

     * Returns the ThreadLocal Session instance.  Lazy initialize

     * the SessionFactory if needed.

     *

     *  @return Session

     *  @throws HibernateException

     */

    public static Session getSession() throws HibernateException {

        Session session = (Session) threadLocal.get();

  

        if (session == null || !session.isOpen()) {

            if (sessionFactory == null) {

                rebuildSessionFactory();

            }

           session = (sessionFactory != null) ? sessionFactory.openSession()

                    : null;

            threadLocal.set(session);

        }

  

        return session;

    }

  

    /**

     *  Rebuild hibernate session factory

     *

     */

    public static void rebuildSessionFactory() {

        try {

            configuration.configure(configFile);

           sessionFactory = configuration.buildSessionFactory();

        } catch (Exception e) {

            System.err

                    .println("%%%% Error Creating SessionFactory %%%%");

            e.printStackTrace();

        }

    }

  

    /**

     *  Close the single hibernate session instance.

     *

     *  @throws HibernateException

     */

    public static void closeSession() throws HibernateException {

        Session session = (Session) threadLocal.get();

        threadLocal.set(null);

  

        if (session != null) {

            session.close();

        }

    }

  

    /**

     *  return session factory

     *

     */

    public static org.hibernate.SessionFactory getSessionFactory() {

        return sessionFactory;

    }

  

    /**

     *  return session factory

     *

     *    session factory will be rebuilded in the next call

     */

    public static void setConfigFile(String configFile) {

        HibernateSessionFactory.configFile = configFile;

        sessionFactory = null;

    }

  

    /**

     *  return hibernate configuration

    *

     */

    public static Configuration getConfiguration() {

        return configuration;

    }

  

}

ExportToDBCreate.java:

 

package cn.edu.ahau.mgc.hibernate.export;

  

import org.hibernate.cfg.Configuration;

import org.hibernate.tool.hbm2ddl.SchemaExport;

  

public class ExportToDBCreate {

  

    public static void main(String[] args) {

        Configuration cfg = new Configuration().configure();

        SchemaExport export = new SchemaExport(cfg);

       export.create(true, true);

    }

  

}

InitData.java:

 

package cn.edu.ahau.mgc.hibernate.export;

  

import java.util.Calendar;

  

import org.hibernate.Session;

  

import cn.edu.ahau.mgc.hibernate.factory.HibernateSessionFactory;

import cn.edu.ahau.mgc.hibernate.pojo.YearPeriod;

import cn.edu.ahau.mgc.hibernate.pojo.YearPeriodPK;

  

public class InitData {

  

    public static void main(String[] args) {

       Session session = null;

        try {

            session = HibernateSessionFactory.getSession();

           session.beginTransaction();

              

            YearPeriodPK yearPeriodPK = new YearPeriodPK();

           yearPeriodPK.setYear(2008);

            yearPeriodPK.setPeriod(1);

              

            YearPeriod yearPeriod = new YearPeriod();

            yearPeriod.setYearPeriodPK(yearPeriodPK);

            Calendar beginDate = Calendar.getInstance();

            beginDate.set(2008, 2, 1);

            Calendar endDate = Calendar.getInstance();

            endDate.set(2008, 6, 1);

            yearPeriod.setBeginDate(beginDate);

            yearPeriod.setEndDate(endDate);

              

           session.save(yearPeriod);

            session.getTransaction().commit();

        } catch (Exception e) {

           session.getTransaction().rollback();

            e.printStackTrace();

       } finally {

            HibernateSessionFactory.closeSession();

        }

    }

  

}

LoadData.java:

 

package cn.edu.ahau.mgc.hibernate.export;

  

import java.text.SimpleDateFormat;

  

import org.hibernate.Session;

  

import cn.edu.ahau.mgc.hibernate.factory.HibernateSessionFactory;

import cn.edu.ahau.mgc.hibernate.pojo.YearPeriod;

import cn.edu.ahau.mgc.hibernate.pojo.YearPeriodPK;

  

public class LoadData {

  

    public static void main(String[] args) {

        Session session = null;

        try {

            session = HibernateSessionFactory.getSession();

            YearPeriodPK yearPeriodPK = new YearPeriodPK();

            yearPeriodPK.setYear(2008);

            yearPeriodPK.setPeriod(1);

              

           YearPeriod yearPeriod = (YearPeriod) session.load(YearPeriod.class, yearPeriodPK);

            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

            System.out.println("Begin Date:" + sdf.format(yearPeriod.getBeginDate().getTime()));

            System.out.println("End Date:" + sdf.format(yearPeriod.getEndDate().getTime()));

              

        } catch (Exception e) {

            e.printStackTrace();

        } finally {

            HibernateSessionFactory.closeSession();

        }

    }

}