action 返回 xml格式

import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;

public String getEditTruckXML(String userID, Long fleetID, Long obtisId) {
		List<FleetTruck> fleetTruckList = new ArrayList<FleetTruck>();
		fleetTruckList = fleetTruckDao.findFleetTruckByFleeID(fleetID);

		List<Fleet> userfleetList = new ArrayList<Fleet>();
		userfleetList = fleetDao.findFleetsByObtisId(obtisId);

		List<FleetTruck> usedTruckList = new ArrayList<FleetTruck>();

		String sql = "from FleetTruck ft ";

		usedTruckList = fleetTruckDao.getFleetTruck(sql, obtisId);

		Document document = DocumentHelper.createDocument();

		Element root = document.addElement("root");

		if (usedTruckList != null && usedTruckList.size() > 0) {
			FleetTruck ft = null;
			for (int j = 0; j < usedTruckList.size(); j++) {
				ft = (FleetTruck) usedTruckList.get(j);

				Element userFleet = [color=red]root[/color].addElement("usedTruck");
				Element trid = userFleet.addElement("tId");
				Element tname = userFleet.addElement("tHK");
				Element tType = userFleet.addElement("tType");
				Element tFName = userFleet.addElement("tFname");
				Element fleet_id = userFleet.addElement("fleet_Id");

				trid
						.addText(String.valueOf(ft.getId().getTruck()
								.getTruckId()));
				tname.addText(ft.getId().getTruck().getLicPlateNoHk());
				tType.addText(ft.getId().getTruck().getVehicleType()
						.getTypeDesc());
				tFName.addText(ft.getId().getFleet().getFleetName());
				fleet_id.addText(ft.getId().getFleet().getFleetId().toString());
			}
		}

		return root.asXML();
	}