public Reader getCharacterStream(String columnName) throws SQLException {
        return getCharacterStream(findColumn(columnName));
    }
Gets the value of the designated column in the current row
of this rowset's <code>ResultSet</code> object as a
<code>java.io.Reader</code> object.

@return a <code>java.io.Reader</code> object that contains the column
value; if the value is SQL <code>NULL</code>, the value returned is
<code>null</code>.
@param columnName the name of the column
@return the value in the specified column as a <code>java.io.Reader</code>
src/main/java/org/replicadb/rowset/sun/rowset/JdbcRowSetImpl.java