rnate 联合主键应用及配置用xml方式实现
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复合（联合）主键映射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 implements java.io.Serializable* 覆写hashcode和equals方法类：import java.io.Serializable;public classNamePK implements Serializable{ //主键类private static final long serialVersionUID = 8313037022835155821L;private String firstName;private String lastName;public String getFirstName() { return firstName;}public void setFirstName(String firstName) { this.firstName = firstName;}public String getLastName() { return lastName;}public void setLastName(String lastName) { this.lastName = lastName;}//重写，交给eclipse自己来写,source/generator hashCode() and equals()public int hashCode() { final int PRIME = 31; int result = 1; result = PRIME * result + ((firstName == null) ? 0 : firstName.hashCode()); result = PRIME * result + ((lastName == null) ? 0 : lastName.hashCode()); return result;}//重写，交给eclipse自己来写public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; final NamePK other = (NamePK) obj; if (firstName == null) { if (other.firstName != null) return false; } else if (!firstName.equals(other.firstName)) return false; if (lastName == null) { if (other.lastName != null) return false; } else if (!lastName.equals(other.lastName)) return false; return true;}}public classUserInfo{privateNamePK namePk;private String sex;private int age;}hbm.xmlUserInfo.hbm.xml<?xml version="1.0" encoding="utf-8"?><!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN""http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"><hibernate-mapping package="com.zd.model"> <class name="UserInfo" table="user_info" > <composite-id name="namePk"> <key-property name="firstName" column="first_name" length="12"/> <key-property name="lastName" column="last_name" length="12"/> </composite-id> <property name="sex" length="12"/> <property name="age" /> </class></hibernate-mapping>测试用例：public void testCompositeId(){ Session session = null; Transaction ta = null; try{ session = HibernateUtil.getSession(); ta = session.beginTransaction(); NamePK namePk = new NamePK(); namePk.setFirstName("Zhang"); namePk.setLastName("san"); UserInfo ui = new UserInfo(); ui.setNamePk(namePk); ui.setSex("M"); ui.setAge(12); session.save(ui); ta.commit(); }catch(Exception e){ e.printStackTrace(); if(ta != null){ ta.rollback(); } }finally{ //关闭session， user变为detached离线对象 HibernateUtil.closeSession(session); } }public void testgetId(){ Session session = null; Transaction ta = null; try{ session = HibernateUtil.getSession(); ta = session.beginTransaction(); NamePK namePk = new NamePK(); namePk.setFirstName("Zhang"); namePk.setLastName("san"); UserInfo ui = (UserInfo) session.get(UserInfo.class, namePk); //get or load均是要序列化的类，所以要把主键implements Serializable System.out.println(ui.getAge()); System.out.println(ui.getSex()); ta.commit(); }catch(Exception e){ e.printStackTrace(); if(ta != null){ ta.rollback(); } }finally{ //关闭session， user变为detached离线对象 HibernateUtil.closeSession(session); } }