JPA - orm.xml (Mapping Descriptor files)

orm.xml is a deployment descriptors describing the object-relational mapping.

The Xsd Schema file can be found:

• orm_2_0.xsd
• or in the specification

The orm.xml file must be placed in the META-INF directory. Each provider will automatically search it in this place.

You can create several mapping files and placed them in a different location. In this case, you must list them in the mapping-file elements of the persistence.xml file:

<persistence-unit name="myPersistenceUnitName">
.........
     <mapping-file>META-INF/myMappingFile1.xml</mapping-file>
     <mapping-file>META-INF/myMappingFile2.xml</mapping-file>
..............
 </persistence-unit>

You do not need to explicitly list it