4.4.3.2. DbTypeConverter
The interface containing methods for conversion between data model attribute values and parameters/results of JDBC queries. An object of this interface can be obtained through the Persistence.getDbTypeConverter() method.
The DbTypeConverter interface has the following methods:
-  getJavaObject()– converts the result of the JDBC query into a type suitable for assigning to entity attribute.
-  getSqlObject()– converts the value of the entity attribute into a type suitable for assigning to the JDBC query parameter.
-  getSqlType()– returns ajava.sql.Typesconstant that corresponds to the passed entity attribute type.