CLOB and BLOB SQL types as parameters or the return value of a CREATE FUNCTION or REPLACE FUNCTION statement map to java.sql.Clob and java.sql.Blob classes respectively.
The implementing class of java.sql.Clob is com.teradata.fnc.Clob and the implementing class of java.sql.Blob is com.teradata.fnc.Blob.
For details on the classes, including methods that you use to get a Blob or Clob for the result of a scalar or aggregate UDF, see Java Application Classes.