In JDBC 4.0, java.sql.SQLXML is the mapping for the SQL XML data type. However, Derby defines the XML data type and operators only in the SQL layer. There is no JDBC-side support for the XML data type and operators
You cannot instantiate a java.sql.SQLXML object in Derby, or bind directly into an XML value or retrieve an XML value directly from a result set. You must bind and retrieve the XML data as Java strings or character streams by explicitly specifying the XML operators, XMLPARSE and XMLSERIALIZE, as part of your SQL queries.
Additionally, Derby does not provide JDBC metatadata support for the XML data type.