xxx.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="com.google.bean">
<class name="Users" table="Users" >
<id name="id" >
<generator class="native"></generator>
</id>
<property name="username" not-null="true" ></property>
<property name="password" not-null="true"></property>
</class>

</hibernate-mapping>