Hibernate系列之繼承關系：共用一個表

hibernate.cfg.xml 的内容：

<?xml version='1.0' encoding='UTF-8'?>

<!DOCTYPE hibernate-configuration PUBLIC

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

          "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<!-- Generated by MyEclipse Hibernate Tools.                   -->

<hibernate-configuration>

<session-factory>

 <property name="connection.username">sa</property>

 <property name="connection.url">

  jdbc:mysql://localhost:3306/db

 </property>

 <property name="dialect">

  org.hibernate.dialect.MySQLDialect

 </property>

 <property name="connection.driver_class">

  com.mysql.jdbc.Driver

 </property>

 <property name="hbm2ddl.auto">create</property>

 <property name="connection.pool_size">100</property>

 <property name="jdbc.batch_size">50</property>

 <property name="cache.use_second_level_cache">false</property>

 <mapping resource="Inheritance/oneTable.hbm.xml" />

</session-factory>

</hibernate-configuration> 

oneTable.hbm.xml 的内容：

<?xml version="1.0" encoding="GB2312"?>

<!DOCTYPE hibernate-mapping SYSTEM "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<hibernate-mapping  auto-import="true" package="Inheritance">

<class name="Payment" table="PAYMENT">

    <id name="id" type="long" column="PAYMENT_ID">

        <generator class="native"/>

    </id>

    <discriminator column="PAYMENT_TYPE" type="string"/>

    <property name="amount" column="AMOUNT"/>

     <subclass name="CreditCardPayment" discriminator-value="CREDIT">

        <property name="creditCardType" column="CCTYPE"/>

    </subclass>

   <subclass name="CashPayment" discriminator-value="CashPayment">

        <property name="CashPaymentType" />

    </subclass>

</class>

</hibernate-mapping>

Payment的内容：

package Inheritance;

public class Payment {

 Long id;

 Long amount;

 public Long getId() {

  return id;

 }

 public void setId(Long id) {

  this.id = id;

 }

 public Long getAmount() {

  return amount;

 }

 public void setAmount(Long amount) {

  this.amount = amount;

 }

}

CashPayment繼承 Payment， 内容如下：

package Inheritance;

public class CashPayment extends Payment {

 String CashPaymentType;

 public String getCashPaymentType() {

  return CashPaymentType;

 }

 public void setCashPaymentType(String cashPaymentType) {

  CashPaymentType = cashPaymentType;

 }

}

CreditCardPayment 也繼承了   Payment，内容如下：

package Inheritance;

public class CreditCardPayment extends Payment {

 String creditCardType;

 public String getCreditCardType() {

  return creditCardType;

 }

 public void setCreditCardType(String creditCardType) {

  this.creditCardType = creditCardType;

 }

}

一下是測試：

HibernateSessionFactory  的内容：

package person;

import org.hibernate.HibernateException;

import org.hibernate.Session;

import org.hibernate.cfg.Configuration;

public class HibernateSessionFactory {

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

 private static final ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();

    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() {

    }

    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;

    }

 public static void rebuildSessionFactory() {

  try {

   configuration.configure(configFile);

   sessionFactory = configuration.buildSessionFactory();

  } catch (Exception e) {

   System.err

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

   e.printStackTrace();

  }

 }

    public static void closeSession() throws HibernateException {

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

        threadLocal.set(null);

        if (session != null) {

            session.close();

        }

    }

 public static org.hibernate.SessionFactory getSessionFactory() {

  return sessionFactory;

 }

 public static void setConfigFile(String configFile) {

  HibernateSessionFactory.configFile = configFile;

  sessionFactory = null;

 }

 public static Configuration getConfiguration() {

  return configuration;

 }

}

主測試類 Main ：

package Inheritance;

import org.hibernate.Session;

import person.HibernateSessionFactory;

public class Main {

 public static void main(String[] args) throws Exception {

  long st = System.currentTimeMillis();

  Session s = HibernateSessionFactory.getSession();

  s.beginTransaction();

  CreditCardPayment  ccp=new CreditCardPayment();

  ccp.setAmount(new Long(222));

  ccp.setCreditCardType("dddd");

  s.save(ccp);

  CashPayment   cash=new CashPayment();

  cash.setAmount(new Long(200));

  cash.setCashPaymentType("cashPaymentType");

  s.save(cash);

  s.getTransaction().commit();

  s.close();

  long end = System.currentTimeMillis();

  System.out.println("用時： ");

  System.out.print(end - st);

 }

}

OK！  有問題 聯系：  qq：81553652