java - Map ArrayList with Hibernate -

i coded first hibernate examples.

the database connection works , understand how can map string pojo database field:

private string firstname; 

and in mapping file:

<property name="firstname" type="java.lang.string">     <column name="firstname" /> </property> 

but how can map arraylist database? simpl example mapping xml file appreciated.

cheers

update

i switched list instead of arraylist found example. map follows:

    <list name="test" inverse="false" table="contact" lazy="true">         <key>             <column name="id" />         </key>         <list-index></list-index>         <element type="java.lang.string">             <column name="test" />         </element>     </list> 

unfortunately, exception not understand:

exception in thread "main" org.hibernate.mappingexception: foreign key (fk6382b0003257ff7f:contact [id])) must have same number of columns referenced primary key (contact [id,idx]) 

any ideas?

cheers

i notice using xml map pojos. find information here.

for example:

   <list name="myarraylistproperty" cascade="all">         <key column="parent_id"/>         <index column="idx"/>         <one-to-many class="whatisinthelist"/>     </list> 

however, using annotations have advantages. this link explain how map collection using annotations.