前言
地理信息系统（GIS）技术在城市规划、交通管理等领域发挥重要作用。湖南省交通网络密集，如何高效管理和展示道路长度信息对交通规划具有重要意义。本文介绍基于 Java 和 Leaflet 构建的湖南省道路长度 WebGIS 系统，通过地图形式直观展示道路里程，方便用户查询分析。
一、基础空间数据简介
1、涉及相关表
| 序号 | 表名 | 说明 |
| 1 | biz_urban_road_mileage_info | 城市道路里程信息表，业务信息表 |
| 2 | biz_geographic_name | 城市名称信息表，点状空间数据表 |
| 3 | biz_city | 市级行政区划信息表，面状空间数据 |
我们需要在地图上展示湖南省各地市的行政区划范围及政府驻地标注信息。数据来源于 OSM，时效性可能非最新，如需权威数据可从官网获取，代码逻辑一致。
2、省域道路长度检索
采用空间数据库表关联业务表进行查询，SQL 如下：
SELECT t1.*, T3.province_code, t3.province_name, st_asgeojson ( t3.geom ) geomJson, st_x ( t2.geom ) lon, st_y ( t2.geom ) lat FROM biz_urban_road_mileage_info t1, biz_geographic_name t2, biz_city t3 WHERE t1.parent_code = '430000' AND t1.city_code = t3.city_code AND T1.city_name = t2.NAME AND st_contains ( t3.geom, t2.geom );
执行后可在客户端查看结果。实际应用中需动态替换省份信息。
二、Java 后台实现
1、道路视图对象
根据业务需要扩展子类，包装成视图对象返回数据。核心代码如下：
package com.yelang.project.extend.earthquake.domain;
import java.io.Serializable;
import com.baomidou.mybatisplus.annotation.TableField;
import lombok.Data;
import lombok.EqualsAndHashCode;
import lombok.ToString;
@Data
@ToString(callSuper=true)
@EqualsAndHashCode(callSuper=false)
public class UrbanRoadMileageInfoVO extends UrbanRoadMileageInfo implements Serializable{
private static final long serialVersionUID = 1101541707654186490L;
@TableField(exist = false,value= "province_code")
private String provinceCode;
@TableField(exist = false,value= "province_name")
private String provinceName;
@TableField(exist = false)
private String geomJson;
private String lat;
private String lon;
}
2、Mapper 空间检索查询
使用 MybatisPlus 进行数据库检索，将 SQL 写入 Mapper 对象。
package com.yelang.project.extend.earthquake.mapper;
import java.util.List;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.yelang.project.extend.earthquake.domain.UrbanRoadMileageInfo;
import com.yelang.project.extend.earthquake.domain.UrbanRoadMileageInfoVO;
public interface UrbanRoadMileageInfoMapper extends BaseMapper<UrbanRoadMileageInfo>{
static final String LIST_BYPROVINCE_SQL = "SELECT t1.city_code,MAX(t1.city_name) AS city_name," +
" SUM(CASE WHEN r.fclass IN ('motorway', 'motorway_link') THEN ST_Length(r.geom::geography) ELSE 0 END) AS highway_length, " +
" SUM(CASE WHEN r.fclass IN ('trunk', 'trunk_link') THEN ST_Length(r.geom::geography) ELSE 0 END) AS trunk_length, " +
" SUM(CASE WHEN r.fclass IN ('primary', 'primary_link') THEN ST_Length(r.geom::geography) ELSE 0 END) AS primary_length, " +
" SUM(CASE WHEN r.fclass IN ('secondary', 'secondary_link') THEN ST_Length(r.geom::geography) ELSE 0 END) AS secondary_length," +
" SUM(CASE WHEN r.fclass IN ('tertiary', 'tertiary_link') THEN ST_Length(r.geom::geography) ELSE 0 END) AS tertiary_length, " +
" SUM(CASE WHEN r.fclass IN ('residential', 'living_street') THEN ST_Length(r.geom::geography) ELSE 0 END) AS residential_length, " +
" SUM(CASE WHEN r.fclass IN ('service', 'unclassified') THEN ST_Length(r.geom::geography) ELSE 0 END) AS service_length, " +
" SUM(CASE WHEN r.fclass IN ('footway', 'pedestrian', 'path') THEN ST_Length(r.geom::geography) ELSE 0 END) AS pedestrian_length, " +
" SUM(CASE WHEN r.fclass = 'cycleway' THEN ST_Length(r.geom::geography) ELSE 0 END) AS cycleway_length, " +
" SUM(CASE WHEN r.fclass = 'track' THEN ST_Length(r.geom::geography) ELSE 0 END) AS track_length," +
+
+
+
;
List<UrbanRoadMileageInfo> ;
+
+
+
+
+
+
;
List<UrbanRoadMileageInfoVO> ;
}
3、控制 API 实现
控制层 API 分为页面跳转和获取各地级市信息列表。
package com.yelang.project.extend.earthquake.controller;
import java.util.List;
import org.apache.shiro.authz.annotation.RequiresPermissions;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import com.yelang.framework.web.controller.BaseController;
import com.yelang.framework.web.domain.AjaxResult;
import com.yelang.project.extend.earthquake.domain.UrbanRoadMileageInfoVO;
import com.yelang.project.extend.earthquake.service.IUrbanRoadMileageInfoService;
@Controller
@RequestMapping("/eq/urbanroadmileageinfo")
public class UrbanRoadMileageInfoController extends BaseController{
private String prefix = "earthquake/urbanroadmileageinfo";
@Autowired
private IUrbanRoadMileageInfoService urbanRoadMileageInfoService;
@RequiresPermissions("eq:urbanroadmileageinfo:map")
@GetMapping("/")
public String main(ModelMap mmap){
return prefix + "/main";
}
@RequiresPermissions("eq:urbanroadmileageinfo:list")
@GetMapping("/data/{pcode}")
@ResponseBody
public AjaxResult {
List<UrbanRoadMileageInfoVO> dataList = urbanRoadMileageInfoService.getRoadMileageList(pcode);
AjaxResult.success().put(, dataList);
}
}
三、WebGIS 界面实现
1、里程图例及初始化
根据不同道路长度设置颜色配置数组。
//里程颜色配置
var colorList = [
{name:"5 千公里以下",color:"#00FF00",rgb:new Color(0, 255, 0),colorDesc:"绿色"},
{name:"5 千 -8 千公里",color:"#FFFF00",rgb:new Color(255, 255, 0),colorDesc:"黄色"},
{name:"8 千 -1.1 万公里",color:"#FFA500",rgb:new Color(255, 165, 0),colorDesc:"蓝色"},
{name:"1.1 万 -1.4 万公里",color:"#113fc1",rgb:new Color(255, 0, 0),colorDesc:"橙色"},
{name:"1.4 万 -1.6 万公里",color:"#800080",rgb:new Color(128, 0, ),:},
{:,:,: (, , ),:}
];
颜色识别转换方法：
function getColorByLength(length){
if(length >= 0 && length <= 5000) { return "#00FF00"; }
if(length >= 5001 && length <= 8000) { return "#FFFF00"; }
if(length >= 8001 && length <= 11000) { return "#FFA500"; }
if(length >= 11001 && length <= 14000) { return "#113fc1"; }
if(length >= 14001 && length <= 16000) { return "#800080"; }
if(length >= 16001) { return "#FF0000"; }
}
2、各地市信息展示
数据库保存单位为米，页面展示需转换为万公里。
function buildShowInfo(index,color,data){
var length = parseFloat(data.totalLength) / (1000.0 * 10000 );
var result = "<div + color + ";' animation-spaceInDown onclick='showDetails("+data.cityCode+")'><div>" + data.cityName ;
result += "<span>:"+ length.toFixed(2) +"万公里</span></div>";
result += "</div>";
return result;
}
道路地图标注方法：
function previewRoadMap(pid,provinceCode,name){
previewProvince(pid,name);
$.ajax({
type:"get",
url:ctx + "eq/urbanroadmileageinfo/data/" + provinceCode,
data:{},
dataType:"json",
cache:false,
processData:false,
success:function(result){
if(result.code == web_status.SUCCESS){
collisionLayer.clearLayers();
var dataArray = result.data;
if(dataArray != null && dataArray.length > 1){
var legendData = new Array();
for(var i =0;i< dataArray.length;i++){
var areaData = dataArray[i];
var tempTotalLength = parseFloat(areaData.totalLength) / 1000.0;
var color = getColorByLength(tempTotalLength);
var areaLayer = L.geoJSON(JSON.parse(areaData.geomJson),{: {:color,:color,:,:, : }}).(mymap);
myIcon = L.({ : , : , :[,], :[,], : (i,color,areaData) });
showLayerGroup.(areaLayer);
L.([areaData., areaData.], { : myIcon}).(collisionLayer);
}
collisionLayer.(showLayerGroup);
}
}
},
:(){
$.modal.();
}
});
}
四、成果展示
1、总体展示
按道路里程降序排序结果如下：
430100 长沙市 17753221.56551351
430400 衡阳市 14434666.394707818
430600 岳阳市 14222249.927994445
430900 益阳市 13073704.1462314
430700 常德市 11931665.375579692
431100 永州市 10818152.494340602
431000 郴州市 10666092.158735342
431200 怀化市 10115713.30456733
430500 邵阳市 9892107.19298748
430200 株洲市 7374936.096146714
433100 湘西土家族苗族自治州 6795835.819083372
431300 娄底市 572764.899432551
430300 湘潭市 4861742.381742725
430800 张家界市 3836270.2965029962
省会长沙市、衡阳市、岳阳市位列前三，空间分布集中在东部和东南部。
2、分区域说明
道路里程较长的集中在东北部的岳阳、益阳、常德等地区和南部的衡阳市。
湘西北的道路里程相对较弱，可能与山区地质环境有关。
南部地区除衡阳外，邵阳、永州、郴州等地市排名中等，未来交通发展需合理规划。
五、总结
本文介绍了基于 Java 和 Leaflet 构建湖南省道路长度 WebGIS 系统的实践。通过将 Java 和 Leaflet 结合，为系统构建提供了良好的技术平台。未来可进一步完善功能，如增加道路拥堵实时监测、与其他交通系统集成，并探索人工智能、大数据等技术应用，为道路管理提供智能化解决方案。
