通过调用blackberry java中的web服务来打印数组数据

Question

这是我到目前为止所编写的代码我在XML文件中获取数组中的所有数据，但我只需要打印VehicleId，请告诉我如何做到这一点我是blackberry webservice的新手。

在我的xml文件中我有这个

{"status":1,"message":"Vehicles List","Vehicles":
     [{"VehicleId":"47","Fuel":"Petrol","Colour":"Green"},
      {"VehicleId":"57","Fuel":"Petrol","Colour":"blue","Used":"True"}]

我在myscreen中的代码是

public final class MyScreen extends MainScreen {
    /**
     * Creates a new MyScreen object
     */
    String inputdata = "";

    public MyScreen() {
    setTitle("MyTitle");
    final VerticalFieldManager vfm = new  VerticalFieldManager();
    final LabelField lbl[];
    lbl = new LabelField[6];
    final LabelField jsonresdata = new LabelField();
    LabelField jsonResult = new LabelField("Webservice", Field.FOCUSABLE) {
        protected boolean navigationClick(int status, int time) {
            Getdata();
            return true;
        }

        public void Getdata() {
            try{
                inputdata = "";
            inputdata = inputdata
                    + "<?xml version='1.0' encoding='utf-8'?>";
            inputdata = inputdata
                    + "<soap:Envelope 
 xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' 
 xmlns:xsd='http://www.w3.org/2001/XMLSchema' 
 xmlns:soap='http://schemas.xmlsoap.org/soap/envelope/'>";
            inputdata = inputdata + "<soap:Body>";
            inputdata = inputdata
                    + "<GetVehicleList xmlns='http://tempuri.org/' />";
            inputdata = inputdata + "</soap:Body>";
            inputdata = inputdata + "</soap:Envelope>";
            final String url = 
"http://156.168.2.112:2345/SERVICE.asmx?op=GetVehicleList";
            try{
                UiApplication.getUiApplication().invokeLater(
                        new Runnable() {
                            public void run() {
             ConnectionClass con = new ConnectionClass();

             try{
            String responsedata = con.CallWebService(url, inputdata, 
  HttpConnection.POST);
            if(responsedata != ""){
                DocumentBuilderFactory dbf = DocumentBuilderFactory
                        .newInstance();
                    DocumentBuilder builder = dbf
                        .newDocumentBuilder();

                    ByteArrayInputStream bis = new ByteArrayInputStream(
                            responsedata.getBytes("UTF-8"));

                    Document doc = builder.parse(bis);
                    doc.getDocumentElement().normalize();
                    final NodeList list;
                    list = doc
                        .getElementsByTagName("GetVehicleListResult");
                   String vehicledata = list.item(0)
                                .getChildNodes()
                                .item(0)
                                .getNodeValue() ;
                   Dialog.alert(vehicledata);
          JSONObject json = new JSONObject(inputdata);  
                   JSONArray a=new JSONArray(json.getString("VehicleId"));
                //    JSONArray jArray= json.getJSONArray("messages"); 
                   for (int i=0; i < a.length(); i++) {
                   lbl[i]=new LabelField(",");
                   vfm.add(lbl[i]);
                   add(vfm);
                   } 
            }else{
                }
             }catch(Exception e){
             }}
                    });
            }catch(Exception e){
                }}
            catch(Exception e){

            }
        }
    };
    add(jsonResult);
add(jsonresdata);
}
}