学步园

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();
	}

}