spacial datablade: how to retrieve a poligon from a database

Hi All, I want to use JDBC to rectrieve a poligon from an informix database. We can represent the poligon as (X1,X2,..., Xn), it is a segment of a table, after retrieving it, i save it in a variable of type Value as a whole , but how can i access X1, X2, .., and Xn ? Thanks ! -Wugang