映射组件属性之②：组件属性为集合

如果组件类再次包含了List、Set、Map等集合属性，则我们可以在<component.../>元素里使用<list.../>，<set.../>和<map.../>子元素来映射这些集合属性。

hibernate.cfg.xml :

<?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="dialect">org.hibernate.dialect.MySQLDialect</property>        <property name="connection.url">jdbc:mysql://localhost:3306/temp</property>        <property name="connection.username">root</property>        <property name="connection.password">mysqladmin</property>        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>        <property name="hbm2ddl.auto">update</property>        <property name="show_sql">true</property>        <property name="format_sql">true</property>        <mapping resource="db/mapping/Person.hbm.xml"/>    </session-factory></hibernate-configuration>

Person.java :

public class Person {private int id;private int age;private Name name;public int getId() {return id;}public void setId(int id) {this.id = id;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public Name getName() {return name;}public void setName(Name name) {this.name = name;}}

Name.java :

public class Name {private String firstname;private String lastname;private Person owner;private Map<String,Integer> power=new HashMap<String,Integer>();//用于从不同角度衡量名字,给你打分public Name() {}public Name(String firstname, String lastname, Map<String, Integer> power) {this.firstname = firstname;this.lastname = lastname;this.power = power;}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;}public Person getOwner() {return owner;}public void setOwner(Person owner) {this.owner = owner;}public Map<String, Integer> getPower() {return power;}public void setPower(Map<String, Integer> power) {this.power = power;}}

Person.hbm.xml :

<?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 package="db.domain">    <class name="Person" table="persons">            <id name="id">            <generator class="identity"></generator>        </id>                <property name="age" type="integer"/>                <!-- 映射组件属性name -->        <component name="name" class="Name" unique="true">            <parent name="owner"/>            <property name="firstname"/>            <property name="lastname"/>            <map name="power" table="name_power">                <key column="person_id" not-null="true"/>                <map-key column="name_aspect" type="string"/>                <element column="name_score" type="integer"/>            </map>        </component>            </class></hibernate-mapping>

Test.java :

public class Test {public static void main(String[] args) {Session session=HibernateSessionFactory.getSession();Transaction txt=session.beginTransaction();Person p1=new Person();p1.setAge(20);Map<String,Integer> power1=new HashMap<String,Integer>();power1.put("易读度",100);power1.put("优雅度",20);Name name1=new Name("张","三",power1);p1.setName(name1);Person p2=new Person();p2.setAge(20);Map<String,Integer> power2=new HashMap<String,Integer>();power2.put("易读度",100);power2.put("优雅度",80);Name name2=new Name("张","三丰",power2);p2.setName(name2);session.save(p1);session.save(p2);txt.commit();HibernateSessionFactory.closeSession();}}