hibernate学习11之composite（复合）主键映射

复合主键映射可以看作是组件映射的一个特例.

<!DOCTYPE hibernate-configuration PUBLIC"-//Hibernate/Hibernate Configuration DTD 3.0//EN""http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"><hibernate-configuration><session-factory><property name="hibernate.connection.url">jdbc:mysql://localhost/hibernate_composite_mapping</property><property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property><property name="hibernate.connection.username">root</property><property name="hibernate.connection.password">bjsxt</property><property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property><property name="hibernate.show_sql">true</property><mapping resource="com/bjsxt/hibernate/FiscalYearPeriod.hbm.xml"/></session-factory></hibernate-configuration>

通常将复合主键相关的属性，单独放到一个类中
* 此类必须实现序列化接口
* 覆写hashcode和equals方法

import java.io.Serializable;public class FiscalYearPeriodPK implements Serializable {//核算年private int fiscalYear;//核算月private int fiscalPeriod;public int getFiscalYear() {return fiscalYear;}public void setFiscalYear(int fiscalYear) {this.fiscalYear = fiscalYear;}public int getFiscalPeriod() {return fiscalPeriod;}public void setFiscalPeriod(int fiscalPeriod) {this.fiscalPeriod = fiscalPeriod;}@Overridepublic int hashCode() {final int prime = 31;int result = 1;result = prime * result + fiscalPeriod;result = prime * result + fiscalYear;return result;}@Overridepublic boolean equals(Object obj) {if (this == obj)return true;if (obj == null)return false;if (getClass() != obj.getClass())return false;final FiscalYearPeriodPK other = (FiscalYearPeriodPK) obj;if (fiscalPeriod != other.fiscalPeriod)return false;if (fiscalYear != other.fiscalYear)return false;return true;}}public class FiscalYearPeriod {//复合主键private FiscalYearPeriodPK fiscalYearPeriodPK;//开始日期private Date beginDate;//结束日期private Date endDate;//状态private String periodSts;//setter，getter}

复合主键映射的配置：

<?xml version="1.0"?><!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN""http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"><hibernate-mapping><class name="com.bjsxt.hibernate.FiscalYearPeriod" table="t_fiscal_year_period"><composite-id name="fiscalYearPeriodPK"><key-property name="fiscalYear"/><key-property name="fiscalPeriod"/></composite-id><property name="beginDate"/><property name="endDate"/><property name="periodSts"/></class></hibernate-mapping>

测试一下：

import java.util.Date;import org.hibernate.Session;import junit.framework.TestCase;public class CompositeMappingTest extends TestCase {public void testSave1() {Session session = null;try {session = HibernateUtils.getSession();session.beginTransaction();FiscalYearPeriod fiscalYearPeriod = new FiscalYearPeriod();FiscalYearPeriodPK pk = new FiscalYearPeriodPK();pk.setFiscalYear(2008);pk.setFiscalPeriod(8);fiscalYearPeriod.setFiscalYearPeriodPK(pk);fiscalYearPeriod.setBeginDate(new Date());fiscalYearPeriod.setEndDate(new Date());fiscalYearPeriod.setPeriodSts("Y");session.save(fiscalYearPeriod);session.getTransaction().commit();}catch(Exception e) {e.printStackTrace();session.getTransaction().rollback();}finally {HibernateUtils.closeSession(session);}}public void testLoad1() {Session session = null;try {session = HibernateUtils.getSession();session.beginTransaction();FiscalYearPeriodPK pk = new FiscalYearPeriodPK();pk.setFiscalYear(2008);pk.setFiscalPeriod(8);FiscalYearPeriod fiscalYearPeriod = (FiscalYearPeriod)session.load(FiscalYearPeriod.class, pk);System.out.println(fiscalYearPeriod.getPeriodSts());session.getTransaction().commit();}catch(Exception e) {e.printStackTrace();session.getTransaction().rollback();}finally {HibernateUtils.closeSession(session);}}}