class O {
  public String field;
}

StringTemplate query = new StringTemplate(
      "UPDATE customers SET customerName='$customer$'," +
      " customerAddress='$address$' WHERE id=$id$ AND $o.field$ IS NOT NULL");

query.setAttribute("customer", "Frank");
query.setAttribute("address", "1313 Mocking Bird Lane");
query.setAttribute("id", "4453");
O o = new O();
o.field = "date";
query.setAttribute("o", o);

System.out.println(query);