COALESCE SQL with Speedment

Code example with Hibernate wich evaluate posible parameters:

  String query = "SELECT * FROM instances";
  String where = "";
  if(userName!=null) {
    where+="AND username = '" + userName + "'";
  }
  if(componentName!=null) {
    where+="AND componentname = '" + componentName + "'";
  }
  if(componentAlias!=null) {
    where+="AND componentalias = '" + componentAlias + "'";
  }
  if(!where.equalsIgnoreCase("")) {
    where = where.substring(3);
    where = " WHERE " + where;
  }
  query = query + where;
  LOGGER.info("Query: " + query);

  Statement s = (Statement) conn.createStatement();
  ResultSet rs = s.executeQuery(query);

How can I do that with Speedment ORM Filters ?