1，操作对象，将数据库里的表映射为持久化类。
一个商品类 Good，一个供应商 Offer类，一个Offer可以提供多个商品。
商品表字段： goodId, offerId, goodName, price .
供应商字段: offerId ,offerName.
Good.hbm.xml
:<hibernate-mapping>
<class name="com.neusoft.Good" table="GOOD" schema="WULIU">
<id name="goodid" type="java.lang.Long">
<column name="GOODID" precision="10" scale="0" />
<generator class="assigned" />
</id>
<many-to-one name="offer" class="com.myweb.Offer" fetch="select">
<column name="OFFERID" precision="10" scale="0" />
</many-to-one>
<property name="goodname" type="java.lang.String">
<column name="GOODNAME" length="40" />
</property>
<property name="price" type="java.lang.Double">
<column name="PRICE" precision="10" />
</property>
</property>
</class>
</hibernate-mapping>
Offer.hbm.xml
<hibernate-mapping>
<class name="com.neusoft.Offer" table="OFFER" schema="WULIU">
<id name="offerid" type="java.lang.Long">
<column name="OFFERID" precision="10" scale="0" />
<generator class="assigned" />
</id>
<property name="offername" type="java.lang.String">
<column name="OFFERNAME" length="30" />
</property>
<set name="goods" inverse="true" lazy="true" cascade="delete" >
<key>
<column name="OFFERID" precision="10" scale="0" />
</key>
<one-to-many class="com.neusoft.Good" />
<!--java.util.Set : private Set goods = new HashSet(0);-->
</set>
</class>
</hibernate-mapping>
lazy="true" 与特定的Offer对象相对应的Good不会像Offer对象一样由同一个SQL查询获取
inverse="true" 表示用此表示两者之间的关系。
cascade="delete" 级联删除
由此配置文件可生成对应的持久化类（即JavaBeans类） Good.java, Offer.java
2. org.hibernate.cfg.Configuration 创建一个HibernateSessionFactory。
import org.hibernate.Session;
import org.hibernate.cfg.Configuration;
public class HibernateSessionFactory {
private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";//xml中配置了数据库的连接信息。
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 org.hibernate.SessionFactory getSessionFactory() {
return sessionFactory;
}
}
(这是用Myeclipse自动生成的代码中一小段)
创建了SessionFactory，就可以用getSession方法来实现操作了，如
public void save(Good transientInstance) {
log.debug("saving Good instance");
try {
getSession().save(transientInstance);
log.debug("save successful");
} catch (RuntimeException re) {
log.error("save failed", re);
throw re;
}
}