Table name metadata

I'm trying to parse the JRXML file to see if there's a way to retrieve the table name of the columns / fields without using alias in the SQL string.  For example, when I have "select * from tableA, tableB where tableA.fk = tableB.id" I would like to find out where each of the field came from.  So far, I can only do it if I have "select a.id as ID_A, b.id as ID_B..." in order to figure it out.  If I have tons of columns, the SQL string will get out of hand and take too long to write.  I see JRField has a getProperties function but the API doc didn't really explain what kind of properties it will hold.