I am trying to load the folowing XML

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">

<hibernate-mapping>
<class name="Department" table="DEPARTMENT">
<id name="did" column="DID">
<generator class="assigned"/>
</id>
<property name="city" column="CITY"/>
<property name="name" column="NAME"/>
<property name="state" column="STATE"/>
<set name="employees" table="EMPLOYEE">
<key column="did"/>
<one-to-many class="Employee"/>
</set>
</class>
</hibernate-mapping>
<!-- parsed in 0ms -->

using the code

Datastore ds = Hibernate.createDatastore();
ds.storeClass(Department.class);

and getting the exception

[ERROR] DatastoreImpl - -Could not configure datastore from input stream <java.lang.NullPointerException>
java.lang.NullPointerException
at cirrus.hibernate.map.Collection.<init>(Collection.java:71)
at cirrus.hibernate.map.Set.<init>(Set.java:26)
at cirrus.hibernate.map.Root$2.create(Root.java:62)
at cirrus.hibernate.map.PersistentClass.propertiesFromXML(PersistentClass.java:71)
at cirrus.hibernate.map.RootClass.<init>(RootClass.java:227)
at cirrus.hibernate.map.Root.<init>(Root.java:135)
at cirrus.hibernate.impl.DatastoreImpl.store(DatastoreImpl.java:106)
at cirrus.hibernate.impl.DatastoreImpl.storeInputStream(DatastoreImpl.java:116)
at cirrus.hibernate.impl.DatastoreImpl.storeClass(DatastoreImpl.java:140)
at JDOTester.<clinit>(JDOTester.java:27)
rethrown as cirrus.hibernate.MappingException
at cirrus.hibernate.impl.DatastoreImpl.storeInputStream(DatastoreImpl.java:124)
at cirrus.hibernate.impl.DatastoreImpl.storeClass(DatastoreImpl.java:140)
at JDOTester.<clinit>(JDOTester.java:27)

define property for dataStore in ur xml file. This helps your program to trace down which dataStore to be used

Datastore ds = Hibernate.createDatastore();
ds.storeClass(Department.class);
I never seen the method createDataStore()??