private boolean clearStationInfo() { // 清空所有记录
    SQLRequestMessage msg = new SQLRequestMessage();
    msg.setCommandMode(Constants.MODE_CS_SYN_CLIENT);
    msg.setCommandType(Constants.TYPE_CLIENT_SQLBATCHDELETE);
    // 从一个表中进行删除操作
    /*
    msg.setCommandType(Constants.TYPE_CLIENT_SQLDELETE);
    msg.setDataBean("District");
    msg.setSql("delete from District");
    */
    String[] sqlArray = new String[6];
    sqlArray[0] = "delete from Station";
    sqlArray[1] = "delete from District";
    sqlArray[2] = "delete from Train";
    sqlArray[3] = "delete from StationDistrictRelation";
    sqlArray[4] = "delete from TrainDistrictRelation";
    sqlArray[5] = "delete from Plan";
    String sqlStr = JsonUtil.array2json(sqlArray);
    msg.setSql(sqlStr);

    String paprams = "null";
    msg.setParams(paprams);

    String list = synClientSupport.sqlMessageSend(msg);
    if (list == null) return false;
    else return true;
  }
  // 从服务器获取信息.
  private void getStationInfo() {
    SQLRequestMessage msg = new SQLRequestMessage();
    msg.setCommandMode(Constants.MODE_CS_SYN_CLIENT);
    msg.setCommandType(Constants.TYPE_CLIENT_SQLQUERY);
    msg.setDataBean("Station");

    // 不带参数的sql语句的使用方法
    msg.setSql("select * from Station order by Station_name "); // limit 16
    String paprams = "null"; //
    msg.setParams(paprams); // 转换为json字符串进行传递

    String listString = synClientSupport.sqlMessageSend(msg); // 同步通信
    if (listString == null) { // 此情况不会出现
      return;
    } else {
      List<Station> list = JsonUtil.getList4Json(listString, Station.class);
      if (list.size() <= 0) return;
      stationData.setData(list);
    }
  }
  // 向服务器发送更新报文
  public boolean updateStationInfo(
      int downAvailLaneNum, int upAvailLaneNum, String map, String stationName) {
    SQLRequestMessage msg = new SQLRequestMessage();
    msg.setCommandMode(Constants.MODE_CS_SYN_CLIENT);
    msg.setCommandType(Constants.TYPE_CLIENT_SQLUPDATE);
    msg.setDataBean("Station");
    msg.setSql(
        "update Station set Station_downnumber=? ,"
            + "Station_upnumber=?,Station_graph=? where Station_name =?");
    if (downAvailLaneNum == 0) downAvailLaneNum = 1;
    if (upAvailLaneNum == 0) upAvailLaneNum = 1;
    Object[] params = new Object[] {downAvailLaneNum, upAvailLaneNum, map, stationName};
    String paprams = JsonUtil.array2json(params);
    msg.setParams(paprams);

    String list = synClientSupport.sqlMessageSend(msg); // 同步通信
    if (list == null) {
      return false;
    } else {
      return true;
    }
  }
  // 参数为车站ID
  // 所有相关的记录都将删除. ??????????????
  public boolean deleteStationInfo(String stationName) {
    SQLRequestMessage msg = new SQLRequestMessage();
    msg.setCommandMode(Constants.MODE_CS_SYN_CLIENT);

    // 从列车区段表District中获取车站ID等于stationID的所有区段的ID
    List<String> districtIDList = new ArrayList<String>();
    msg.setCommandType(Constants.TYPE_CLIENT_SQLQUERY);
    msg.setDataBean("District");
    String sqlStr =
        "select * from District where District_startstationname='"
            + stationName
            + "' or District_endstationname='"
            + stationName
            + "'";
    msg.setSql(sqlStr);
    String paprams = "null";
    msg.setParams(paprams);
    String listString = synClientSupport.sqlMessageSend(msg);
    if (listString == null) { // 此情况不会出现
      districtIDList = null;
    } else {
      List<District> list = JsonUtil.getList4Json(listString, District.class);
      if (list.size() <= 0) districtIDList = null;
      else {
        for (int i = 0; i < list.size(); i++) {
          District data = (District) list.get(i);
          districtIDList.add(data.getDistrict_name());
        }
      }
    }

    // 从列车表Train中获取车站ID等于stationID的所有车次的ID
    List<String> trainIDList = new ArrayList<String>();
    msg.setDataBean("Train");
    sqlStr =
        "select * from Train where Train_startstationname='"
            + stationName
            + "' or Train_endstationname='"
            + stationName
            + "'";
    msg.setSql(sqlStr);
    paprams = "null";
    msg.setParams(paprams);
    listString = synClientSupport.sqlMessageSend(msg);
    if (listString == null) { // 此情况不会出现
      trainIDList = null;
    } else {
      List<Train> list = JsonUtil.getList4Json(listString, Train.class);
      if (list.size() <= 0) trainIDList = null;
      else {
        for (int i = 0; i < list.size(); i++) {
          Train data = (Train) list.get(i);
          trainIDList.add(data.getTrain_name());
        }
      }
    }

    // 批量删除
    // 涉及到的表:Station, District Train StationDistrictRelation TrainDistrictRelation
    int districtNumber = 0;
    int trainNumber = 0;
    if (districtIDList != null) districtNumber = districtIDList.size();
    if (trainIDList != null) trainNumber = trainIDList.size();

    String[] sqlArray = new String[5 + districtNumber * 2 + trainNumber];

    int index = 0;

    sqlArray[index++] = "delete from Station where Station_name='" + stationName + "'"; // number 1
    sqlArray[index++] =
        "delete from StationDistrictRelation where Station_name='" + stationName + "'"; // number 1
    sqlArray[index++] =
        "delete from Plan where Station_name='"
            + stationName
            + "' or Prestation_name='"
            + stationName
            + "'"; // number 1

    if (districtIDList != null) {
      sqlArray[index++] =
          "delete from District where District_startstationname='"
              + stationName
              + "' or District_endstationname='"
              + stationName
              + "'"; // number 1
      for (int i = 0; i < districtNumber; i++) { // number districtNumber*2
        sqlArray[index++] =
            "delete from StationDistrictRelation where District_name='"
                + districtIDList.get(i)
                + "'";
        sqlArray[index++] =
            "delete from TrainDistrictRelation where District_name='" + districtIDList.get(i) + "'";
      }
    }
    if (trainIDList != null) {
      sqlArray[index++] =
          "delete from Train where Train_startstationname='"
              + stationName
              + "' or Train_endstationname='"
              + stationName
              + "'"; // number 1
      for (int i = 0; i < trainNumber; i++) { // number trainNumber
        sqlArray[index++] =
            "delete from TrainDistrictRelation where Train_name='" + trainIDList.get(i) + "'";
      }
    }
    msg.setCommandType(Constants.TYPE_CLIENT_SQLBATCHDELETE);
    sqlStr = JsonUtil.array2json(sqlArray);
    msg.setSql(sqlStr);
    paprams = "null";
    msg.setParams(paprams);

    listString = synClientSupport.sqlMessageSend(msg); // 同步通信
    if (listString == null) {
      return false;
    } else {
      return true;
    }
  }