休眠中的复合主键问题

Question

I am creating a hibernate application in which i want to create a composite primary key . Following is the mapping file I have written:

<?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>
  <class name="Fold.ChildrenPark" table="ChildrenPark">
    <composite-id>
    <key-property name="date" not-null="true"/>
    <key-property name="valveOffTime" not-null="true"/>
    <key-property name="valveOnTime" not-null="true"/>
    </composite-id>
    <property name="overHeadTankLevelAfterFilling"/>
    <property name="overHeadTankLevelBeforeFilling"/>
    <property name="rank"/>
  </class>
</hibernate-mapping>

But I am getting exception as follows:

 - 1689 [http-listener-1(4)] ERROR org.hibernate.util.xml.ErrorLogger -
   Error parsing XML (11) : Attribute "not-null" must be declared for
   element type "key-property". Severe:   1717 [http-listener-1(4)] WARN
   org.hibernate.util.DTDEntityResolver - recognized obsolete hibernate
   namespace http://hibernate.sourceforge.net/. Use namespace
   http://www.hibernate.org/dtd/ instead. Refer to Hibernate 3.6
   Migration Guide! Severe:   1719 [http-listener-1(4)] ERROR
   org.hibernate.util.xml.ErrorLogger - Error parsing XML (2) :
   Attribute "not-null" must be declared for element type
   "key-property". Info:   Exception in insertion of data:
   org.hibernate.InvalidMappingException: Unable to read XML

So i want to know what is missing to be provided in this code.I searched on net but didn't find anything useful.What does it means?

Answer 1

There are many things :

1/ change your dtd from :

<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

to:

<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

this will remove the warning about obsolete hibernate namespace

2/ Remove not-null attribute for key-property, this attribute does not exists for key-property since a PK property cannot be null.