1. 首先是一个User2类：这个类用name和phone两个属性作为一个User2的识别标志package CompoundKeys;import java.io.Serializable;//import org.apache.commons.lang.builder.EqualsBuilder;//import org.apache.commons.lang.builder.HashCodeBuilder;/* 当然可以將主鍵的資訊獨立為一個類別*/// 複合主鍵類的對應類別必須實作Serializable介面public class User2 implements Serializable{ private String name;//这里两个变量共同构成一个主键 private String phone; private Integer age; public User2() { } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getPhone() { return phone; } public void setPhone(String phone) { this.phone = phone; } // 必須重新定義equals()與hashCode() public boolean equals(Object obj) { if(obj == this) { return true;} if(!(obj instanceof User2)){return false;} User2 user = (User2) obj; //这个需要单独的包 //return new EqualsBuilder() // .append(this.name, user.getName()) // .append(this.phone, user.getPhone()) // .isEquals(); // return this.name.equals(user.getName())&&this.phone.equals(user.getPhone()); } public int hashCode() { // //return new HashCodeBuilder() // .append(this.name) // .append(this.phone) // .toHashCode(); // return (name== null||phone==null) ? System.identityHashCode(this) : 29*name.hashCode()+phone.hashCode();
}
}
2。匹配方法：<?xml version="1.0" encoding="GBK"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping> <class name="CompoundKeys.User2" table="user"> <composite-id> <key-property name="name" column="name" type="java.lang.String"/> <key-property name="phone" column="phone" type="java.lang.String"/> </composite-id> <property name="age" column="age" type="java.lang.Integer"/> </class> </hibernate-mapping>
3。Hibernate.cfg.xml: 注意这里我在前面例子的基础上加的<?xml version='1.0' encoding='GBK'?><!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!--Database connection settings --> <property name="connection.driver_class">com.mysql.jdbc.Driver</property> <property name="connection.url">jdbc:mysql://localhost/yay</property> <property name="connection.username">root</property> <property name="connection.password">qwe123</property>
<!-- SQL dialect --> <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<!-- Enable Hibernate's automatic session context management --> <property name="current_session_context_class">thread</property>
<!-- Disable the second-level cache --> <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
<!-- Echo all executed SQL to stdout --> <property name="show_sql">false</property>
<!-- Drop and re-create the database schema on startup --> <!--property name="hbm2ddl.auto">create</property-->
<!--DBCP连接池设置，不用DBCP的时候，就不要这个配置部分--> <property name="DBCP.min_size">5</property> <property name="DBCP.max_size">20</property> <property name="DBCP.timeout">1800</property> <property name="DBCP.max_statements">50</property> <!--这个配置mysql不支持：100个数据后就自动提交。这个可以不用配置--> <property name="hibernate.jdbc.batch_size">100</property> <!--这个指定事务管理用哪个，依賴於JDBC或JTA的事務管理功能，預設是使用JDBC事務管理--> <property name="hibernate.transaction.factory_class"> org.hibernate.transaction.JDBCTransactionFactory </property>
<mapping resource="events/Event.hbm.xml"/> <mapping resource="events/Person.hbm.xml"/> <mapping resource="MulToOne/Room.hbm.xml"/> <mapping resource="MulToOne/User.hbm.xml"/> <!--下面是复合主键--> <mapping resource="CompoundKeys/User2.hbm.xml"/> </session-factory>
</hibernate-configuration>
4。测试方法：package CompoundKeys;
import org.hibernate.*;import org.hibernate.cfg.*;import java.util.*;/*
1。说明的是，这里我只所以取名为User2而不是User类的目的是 当你的hibernate.cfg.xml中已经有了一个User类配置文件的时候，会发生混乱， 甚至会报告说配置文件错误。
*/
public class TestUser{ public static void main(String[] args) { TestUser.Test(); } public static void Test() { Session session =util.HibernateUtil.getSessionFactory().getCurrentSession(); Transaction tx = session.beginTransaction(); User2 user = new User2(); user.setName("bush"); user.setPhone("0970123456"); session.save(user); user = (User2) session.load(User2.class, user); System.out.println(user.getAge() + "/t" + user.getName() + "/t" + user.getPhone()); tx.commit(); util.HibernateUtil.getSessionFactory().close();
}}
