Java对关于两个地点的根据经纬度算出后排序

/**
     * 查询收货地址列表
     * 
     * @param request
     * @param wechatId
     * @return
     */
    @RequestMapping("/weixin/address/queryRecentlyAddress")
    public AddressVo queryRecentlyAddress(HttpServletRequest request, Integer wechatId, AddressVo vo) {
        String openId = OauthUtil.getInstance().getOpenId(request, String.valueOf(wechatId));
        // 查询收货地址
        Map<String, Object> map = new HashMap<String, Object>();
        String nowLng = (String) request.getAttribute("Lng");
        String nowLat = (String) request.getAttribute("Lat");
        
        map.put("openId", openId);
        List<AddressVo> aList = addressService.queryList(map);
        //TreeMap具有更具key做自动排序的功能，默认为正序即从小到大
        Map<Double,AddressVo> addressMap=new TreeMap<Double,AddressVo>();
        for(AddressVo address:aList){
            String latitude = address.getLatitude();
            String longitude = address.getLongitude();
            double distance = Distance(nowLng,nowLat,latitude,longitude);
            addressMap.put(distance,address);
        }
        AddressVo addressVo = addressMap.get(0);
        return addressVo;
    }

//根据两个地点的经纬度，计算两的距离
      private static final double EARTH_RADIUS = 6378.137;
 
      private static double rad(double d){
                      return d * Math.PI / 180.0;
           }
 
 
 
    public  double Distance(String nowLng, String nowLat, String latitude, String longitude) {
            double long1;
            double lat1;
            double long2;
            double lat2;
            double a, b, sa2, sb2,d = 0;
            try {
                  long1 = Double.valueOf(nowLng);
                   lat1 = Double.valueOf(nowLat);
                   long2 = Double.valueOf(latitude);
                   lat2 = Double.valueOf(longitude);
                   lat1 = rad(lat1);
                   lat2 = rad(lat2);
                    a = lat1 - lat2;
                    b = rad(long1 - long2);
                    sa2 = Math.sin(a / 2.0);
                    sb2 = Math.sin(b / 2.0);
                    d = 2   * EARTH_RADIUS
                            * Math.asin(Math.sqrt(sa2 * sa2 + Math.cos(lat1)
                            * Math.cos(lat2) * sb2 * sb2));
                    
            } catch (Exception e) {
            
                e.printStackTrace();
            }
            return d;
   }