整體思路是用geoserver發佈圖層,圖層爲 sql,視圖是利用存儲過程分析出的路徑結果,
shp導入數據庫
路網一般爲shp數據,如果有多個圖層,建議利用arcgis或其他工具合併爲一個圖層,方便處理
數據庫空間擴展
使用paAdmin3連接PostgreSQL,並執行以下語句,在新的空間數據庫裏添加空間擴展:
CREATE EXTENSION postgis;
CREATE EXTENSION pgrouting;
CREATE EXTENSION postgis_topology;
CREATE EXTENSION fuzzystrmatch;
CREATE EXTENSION postgis_tiger_geocoder;
CREATE EXTENSION address_standardizer;
使用shp2pgsql-gui.exe導入
添加路網數據,設置表名,並設置SRID爲:4326
需要使用GBK編碼,一定要勾選最下面一個選項。(在調用函數做測試的時候,遇到ST_Line_Locate_Point時報錯:“line_locate_point : 1st arg isnt a line”,查資料解釋說是函數第一個參數格式應該是LineString,我檢查了一下我的v_res格式,是MultiLineString所以報錯。(參考了https://www.jianshu.com/p/4b9d22406bce,在此謝謝作者大大,很詳細))
表結構進行修改
1.修改表結構
--添加起點id
ALTER TABLE lproad ADD COLUMN source integer;
--添加終點id
ALTER TABLE lproad ADD COLUMN target integer;
--添加道路權重值
ALTER TABLE lproad ADD COLUMN length double precision
2.創建拓撲結構
--爲lproad表創建拓撲佈局,即爲source和target字段賦值
SELECT pgr_createTopology('lproad ',0.0001, 'geom', 'gid');
3.創建索引
--爲source和target字段創建索引
CREATE INDEX source_idx ON lproad ("source");
CREATE INDEX target_idx ON lproad ("target");
4.添加線段端點並給長度賦值
--添加線段端點座標
ALTER TABLE lproad ADD COLUMN x1 double precision; --創建起點經度x1
ALTER TABLE lproad ADD COLUMN y1 double precision; --創建起點緯度y1
ALTER TABLE lproad ADD COLUMN x2 double precision; --創建起點經度x2
ALTER TABLE lproad ADD COLUMN y2 double precision; --創建起點經度y2
--給x1、y1、x2、y2賦值
UPDATE lproad SET x1 =ST_x(ST_PointN(geom, 1));
UPDATE lproad SET y1 =ST_y(ST_PointN(geom, 1));
UPDATE lproad SET x2 =ST_x(ST_PointN(geom, ST_NumPoints(geom)));
UPDATE lproad SET y2 =ST_y(ST_PointN(geom, ST_NumPoints(geom)));
--爲length賦值
update lproad set length =st_length(geom);
--爲lproad 表添加reverse_cost字段並用length的值賦值
ALTER TABLE lproad ADD COLUMN reverse_cost double precision;
UPDATE lproad SET reverse_cost =length;
測試數據,如果執行下面的語句有結果,則表示數據預處理成功
--通過起點號、終點號查詢最短路徑
--source爲線表起點字段名稱
--target爲線表終點字段名稱
--起點終點前後順序無固定要求
--length爲長度字段,也可以使用自己的評價體系
--1、9爲測試使用起點號\終點號
--zy表名
--id1經過節點號
--id2經過路網線的gid
SELECT seq, id1 AS node, id2 AS edge, cost FROM pgr_dijkstra('
SELECT gid AS id,
source::integer,
target::integer,
length::double precision AS cost
FROM lproad ',
1, 4, false, false);
創建最短路徑函數
-- DROP FUNCTION public.pgr_fromatoe(double precision, double precision, double precision, double precision);
CREATE OR REPLACE FUNCTION pgr_fromatoe(
tbl varchar,
startx double precision,
starty double precision,
endx double precision,
endy double precision)
RETURNS geometry
LANGUAGE 'plpgsql'
COST 100
VOLATILE STRICT
AS $BODY$
declare
v_startLine geometry;--離起點最近的線
v_endLine geometry;--離終點最近的線
v_startTarget integer;--距離起點最近線的終點
v_startSource integer;
v_endSource integer;--距離終點最近線的起點
v_endTarget integer;
v_statpoint geometry;--在v_startLine上距離起點最近的點
v_endpoint geometry;--在v_endLine上距離終點最近的點
v_res geometry;--最短路徑分析結果
v_res_a geometry;
v_res_b geometry;
v_res_c geometry;
v_res_d geometry;
v_start_temp geometry;
v_start_temp1 geometry;
v_start_temp2 geometry;
v_end_temp geometry;
v_end_temp1 geometry;
v_end_temp2 geometry;
v_perStart float;--v_statpoint在v_res上的百分比
v_perEnd float;--v_endpoint在v_res上的百分比
v_shPath_se geometry;--開始到結束
v_shPath_es geometry;--結束到開始
v_shPath geometry;--最終結果
tempnode float;
startpoint geometry;
endpoint geometry;
v_shPath1 geometry;--一次結果
v_shPath2 geometry;--二次結果
star_line geometry; --起點到最近點的線
end_line geometry; --終點到最近點的線
geoARR geometry[];
begin
--查詢離起點最近的線
--4326座標系
--找起點15米範圍內的最近線
execute 'select geom, source, target from '|| tbl ||
' where ST_DWithin(geom,ST_Geometryfromtext(''point('|| startx ||' ' || starty||')'',4326),3000)
order by ST_Distance(geom,ST_GeometryFromText(''point('|| startx ||' '|| starty ||')'',4326)) limit 1'
into v_startLine, v_startSource ,v_startTarget;
raise notice '%', v_startSource;
raise notice '%', v_startTarget;
--查詢離終點最近的線
--找終點15米範圍內的最近線
execute 'select geom, source, target from '|| tbl ||
' where ST_DWithin(geom,ST_Geometryfromtext(''point('|| endx || ' ' || endy ||')'',4326),3000)
order by ST_Distance(geom,ST_GeometryFromText(''point('|| endx ||' ' || endy ||')'',4326)) limit 1'
into v_endLine, v_endSource,v_endTarget;
raise notice '%', v_endSource;
raise notice '%', v_endTarget;
--如果沒找到最近的線,就返回null
if (v_startLine is null) or (v_endLine is null) then
return null;
end if ;
select ST_ClosestPoint(v_startLine, ST_Geometryfromtext('point('|| startx ||' ' || starty ||')',4326)) into v_statpoint;
select ST_ClosestPoint(v_endLine, ST_GeometryFromText('point('|| endx ||' ' || endy ||')',4326)) into v_endpoint;
-- ST_Distance
--從開始的起點到結束的起點最短路徑
execute 'SELECT st_linemerge(st_union(b.geom)) ' ||
'FROM pgr_kdijkstraPath(
''SELECT gid as id, source, target, length as cost FROM '|| tbl ||' '','
||v_startSource || ', ' ||'array['||v_endSource||'] , false, false
) a, lproad b
WHERE a.id3=b.gid
GROUP by id1
ORDER by id1' into v_res ;
--從開始的終點到結束的起點最短路徑
execute 'SELECT st_linemerge(st_union(b.geom)) ' ||
'FROM pgr_kdijkstraPath(
''SELECT gid as id, source, target, length as cost FROM '|| tbl ||' '','
||v_startTarget || ', ' ||'array['||v_endSource||'] , false, false
) a, lproad b
WHERE a.id3=b.gid
GROUP by id1
ORDER by id1' into v_res_b ;
--從開始的起點到結束的終點最短路徑
execute 'SELECT st_linemerge(st_union(b.geom)) ' ||
'FROM pgr_kdijkstraPath(
''SELECT gid as id, source, target, length as cost FROM '|| tbl ||' '','
||v_startSource || ', ' ||'array['||v_endTarget||'] , false, false
) a, lproad b
WHERE a.id3=b.gid
GROUP by id1
ORDER by id1' into v_res_c ;
--從開始的終點到結束的終點最短路徑
execute 'SELECT st_linemerge(st_union(b.geom)) ' ||
'FROM pgr_kdijkstraPath(
''SELECT gid as id, source, target, length as cost FROM '|| tbl ||' '','
||v_startTarget || ', ' ||'array['||v_endTarget||'] , false, false
) a, lproad b
WHERE a.id3=b.gid
GROUP by id1
ORDER by id1' into v_res_d ;
if(ST_Length(v_res) > ST_Length(v_res_b)) then
v_res = v_res_b;
end if;
if(ST_Length(v_res) > ST_Length(v_res_c)) then
v_res = v_res_c;
end if;
if(ST_Length(v_res) > ST_Length(v_res_d)) then
v_res = v_res_d;
end if;
--如果找不到最短路徑,就返回null
if(v_res is null) then
return null;
end if;
--將v_res,v_startLine,v_endLine進行拼接
--select st_linemerge(ST_Union(array[v_startLine,v_res,v_endLine])) into v_res;
select ST_LineLocatePoint(v_startLine, v_statpoint) into v_perStart;
select ST_LineLocatePoint(v_endLine, v_endpoint) into v_perEnd;
SELECT ST_Line_SubString(v_startLine,v_perStart, 1) into v_start_temp1;
SELECT ST_Line_SubString(v_startLine,0,v_perStart) into v_start_temp2;
SELECT ST_Line_SubString(v_endLine,v_perEnd, 1) into v_end_temp1;
SELECT ST_Line_SubString(v_endLine,0,v_perEnd) into v_end_temp2;
raise notice '%', v_perStart;
raise notice '%', v_perEnd;
raise notice '%', ST_Distance(v_res,v_start_temp1);
raise notice '%', ST_Distance(v_res,v_start_temp2);
raise notice '%', ST_Distance(v_res,v_end_temp2);
raise notice '%', ST_Distance(v_res,v_end_temp1);
v_start_temp=v_start_temp1;
if(ST_Distance(v_res,v_start_temp1) > ST_Distance(v_res,v_start_temp2)) then
v_start_temp=v_start_temp2;
end if;
v_end_temp=v_end_temp1;
if(ST_Distance(v_res,v_end_temp1) > ST_Distance(v_res,v_end_temp2)) then
v_end_temp=v_end_temp2;
end if;
--return ST_AsGeoJSON(v_res);
--return v_res;
-- select ST_LineLocatePoint(v_res, v_statpoint) into v_perStart;
-- select ST_LineLocatePoint(v_res, v_endpoint) into v_perEnd;
--if(v_perStart > v_perEnd) then
-- tempnode = v_perStart;
-- v_perStart = v_perEnd;
-- v_perEnd = tempnode;
--end if;
--截取v_res
--拼接線
--SELECT ST_Line_SubString(v_res,v_perStart, v_perEnd) into v_shPath1;
select st_linemerge(ST_Union(array[v_start_temp,v_res,v_end_temp])) into v_shPath1;
return v_shPath1;
--後續爲將起點終點與路網連接起來,因發佈時有點問題,暫不使用
--找線的端點
select ST_SetSRID( ST_MakePoint(startx , starty),4326 )into startpoint;
select ST_SetSRID( ST_MakePoint(endx , endy),4326 )into endpoint;
select ST_MakeLine( v_statpoint,startpoint) into star_line;
select ST_MakeLine( v_endpoint,endpoint) into end_line;
geoARR :=array[end_line,v_shPath1,star_line];
select st_union(geoARR) into v_shPath;
raise notice '%', '返回數據';
--raise notice '%', ST_AsGeoJSON(v_shPath);
return v_shPath;
end;
$BODY$;
數據發佈
數據準備完成後,就需要用GeoServer來進行發佈:
啓動GeoServer,在瀏覽器中輸入,http://localhost:8080/geoserver/web/,登錄到GeoServer。
1.創建工作區
2.添加數據存儲
配置數據庫連接
3.添加圖層
選擇“配置新的SQL視圖”,輸入SQL語句:
SELECT * FROM pgr_fromAtoB('lproad', %x1%, %y1%, %x2%, %y2%)
驗證的正則表達式:^-?[d.]+$
類型:LingString
SRID:4326
點擊保存後,填入SRS,並自動計算範圍
結果展示
1、wms方式加載
var viewparams = [
'x1:' + startCoord[0], 'y1:' + startCoord[1],
'x2:' + destCoord[0], 'y2:' + destCoord[1]
];
params.viewparams = viewparams.join(';');
result = new ol.layer.Image({
source: new ol.source.ImageWMS({
url: ServerUrl + '/geoserver/Routing/wms',
params: params
})
});
map.addLayer(result);
2、wfs方式加載
var vectorSource = new ol.source.Vector({
format: new ol.format.GeoJSON(),
url: function (extent) {
return ServerUrl + '/geoserver/wfs?service=WFS&' +
'version=1.1.0&request=GetFeature&typename=Routing:lproute&' +
'outputFormat=application/json&srsname=EPSG:4326&' +
'bbox=' + extent.join(',') + ',EPSG:4326&' +
'viewparams=' + viewparams.join(';');
},
strategy: ol.loadingstrategy.bbox
});
var vector = new ol.layer.Vector({
source: vectorSource,
});
map.addLayer(vector);
3、直接請求服務
var wfsurl = ServerUrl + '/geoserver/wfs?service=WFS&' +
'version=1.1.0&request=GetFeature&typename=Routing:lproute&' +
'outputFormat=application/json&srsname=EPSG:4326&' +
'viewparams=' + viewparams.join(';');
$.ajax({
url: wfsurl,
success: function (result) {
console.log(result);
}
});
效果如圖:
這是我自己開發的一個關於答題的兩個小工具,感興趣的可以瞭解下。打開微信掃描一下下面的二維碼即可體驗。 (也可以微信搜索 “ PK答題王 ” “科目一駕照”) 需要源碼的可以聯繫我 qq:337882150