概述：

在前文中，讲述了在JAVA环境下如何将shp转换为GeoJSON，在本文，分别讲述在Arcgis for js，Openlayers2和Openlayers3中加载展示GeoJSON。

实现：

1、Openlayers2中加载GeoJSON

在OL2中，可以直接调用OL2的借口实现GeoJSON的加载，代码示例：

    
            
                    
    
    
     
        
      add GeoJSON    
     
    

实现效果如下图：

2、Openlayers3中加载GeoJSON

在OL3中也可直接调用OL3的接口展示GeoJSON数据，示例代码如下：

	
    		
    				
    
	
     
		
      add GeoJSON	
     
	
     
	
     
		
      地图控制
      
		
      			visibility				
      
		
      opacity		
      
      
		
      rotation		
      	
     
    

实现后效果如下：

3、Arcgis for js中加载GeoJSON

在Arcgis中没法直接利用接口加载GeoJSON，不过可以通过GraphicsLayer和Graphic实现GeoJSON的加载。示例代码如下：

在上面的代码中，有一个GeoJsonConverter，是我编写的一个函数，实现GeoJSON到Arcgis JSON的转换，代码如下：

function geoJsonConverter(){    var gCon = {};    /*compares a GeoJSON geometry type and ESRI geometry type to see if they can be safely     put together in a single ESRI feature. ESRI features must only have one     geometry type, point, line, polygon*/    function isCompatible(esriGeomType, gcGeomType) {        var compatible = false;        if ((esriGeomType === "esriGeometryPoint" || esriGeomType === "esriGeometryMultipoint") && (gcGeomType === "Point" || gcGeomType === "MultiPoint")) {            compatible = true;        } else if (esriGeomType === "esriGeometryPolyline" && (gcGeomType === "LineString" || gcGeomType === "MultiLineString")) {            compatible = true;        } else if (esriGeomType === "esriGeometryPolygon" && (gcGeomType === "Polygon" || gcGeomType === "MultiPolygon")) {            compatible = true;        }        return compatible;    }    /*Take a GeoJSON geometry type and make an object that has information about     what the ESRI geometry should hold. Includes the ESRI geometry type and the name     of the member that holds coordinate information*/    function gcGeomTypeToEsriGeomInfo(gcType) {        var esriType,            geomHolderId;        if (gcType === "Point") {            esriType = "esriGeometryPoint";        } else if (gcType === "MultiPoint") {            esriType = "esriGeometryMultipoint";            geomHolderId = "points";        } else if (gcType === "LineString" || gcType === "MultiLineString") {            esriType = "esriGeometryPolyline";            geomHolderId = "paths";        } else if (gcType === "Polygon" || gcType === "MultiPolygon") {            esriType = "esriGeometryPolygon";            geomHolderId = "rings";        }        return {            type: esriType,            geomHolder: geomHolderId        };    }    /*Convert GeoJSON polygon coordinates to ESRI polygon coordinates.     GeoJSON rings are listed starting with a singular outer ring. ESRI     rings can be listed in any order, but unlike GeoJSON, the ordering of     vertices determines whether it's an outer or inner ring. Clockwise     vertices indicate outer ring and counter-clockwise vertices indicate     inner ring */    function gcPolygonCoordinatesToEsriPolygonCoordinates(gcCoords) {        var i,            len,            esriCoords = [],            ring;        for (i = 0, len = gcCoords.length; i < len; i++) {            ring = gcCoords[i];            // Exclusive OR.            if ((i === 0) !== ringIsClockwise(ring)) {                ring = ring.reverse();            }            esriCoords.push(ring);        }        return esriCoords;    }    /*Wraps GeoJSON coordinates in an array if necessary so code can iterate     through array of points, rings, or lines and add them to an ESRI geometry     Input is a GeoJSON geometry object. A GeoJSON GeometryCollection is not a     valid input */    function gcCoordinatesToEsriCoordinates(gcGeom) {        var i,            len,            esriCoords;        if (gcGeom.type === "MultiPoint" || gcGeom.type === "MultiLineString") {            esriCoords = gcGeom.coordinates || [];        } else if (gcGeom.type === "Point" || gcGeom.type === "LineString") {            esriCoords = gcGeom.coordinates ? [gcGeom.coordinates] : [];        } else if (gcGeom.type === "Polygon") {            esriCoords = [];            if(gcGeom.coordinates){                esriCoords = gcPolygonCoordinatesToEsriPolygonCoordinates(gcGeom.coordinates);            }        } else if (gcGeom.type === "MultiPolygon") {            esriCoords = [];            if(gcGeom.coordinates){                for (i = 0, len = gcGeom.coordinates.length; i < len; i++) {                    esriCoords.push(gcPolygonCoordinatesToEsriPolygonCoordinates(gcGeom.coordinates[i]));                }            }        }        return esriCoords;    }    /*Converts GeoJSON geometry to ESRI geometry. The ESRI geometry is     only allowed to contain one type of geometry, so if the GeoJSON     geometry is a GeometryCollection, then only geometries compatible     with the first geometry type in the collection are added to the ESRI geometry     Input parameter is a GeoJSON geometry object.*/    function gcGeometryToEsriGeometry(gcGeom) {        var esriGeometry,            esriGeomInfo,            gcGeometriesToConvert,            i,            g,            coords;        //if geometry collection, get info about first geometry in collection        if (gcGeom.type === "GeometryCollection") {            var geomCompare = gcGeom.geometries[0];            gcGeometriesToConvert = [];            esriGeomInfo = gcGeomTypeToEsriGeomInfo(geomCompare.type);            //loop through collection and only add compatible geometries to the array            //of geometries that will be converted            for (i = 0; i < gcGeom.geometries.length; i++) {                if (isCompatible(esriGeomInfo.type, gcGeom.geometries[i].type)) {                    gcGeometriesToConvert.push(gcGeom.geometries[i]);                }            }        } else {            esriGeomInfo = gcGeomTypeToEsriGeomInfo(gcGeom.type);            gcGeometriesToConvert = [gcGeom];        }        //if a collection contained multiple points, change the ESRI geometry        //type to MultiPoint        if (esriGeomInfo.type === "esriGeometryPoint" && gcGeometriesToConvert.length > 1) {            esriGeomInfo = gcGeomTypeToEsriGeomInfo("MultiPoint");        }        //make new empty ESRI geometry object        esriGeometry = {            //type: esriGeomInfo.type,            spatialReference: {                wkid: 4326            }        };        //perform conversion        if (esriGeomInfo.type === "esriGeometryPoint") {            if (!gcGeometriesToConvert[0] || !gcGeometriesToConvert[0].coordinates || gcGeometriesToConvert[0].coordinates.length === 0) {                esriGeometry.x = null;            } else {                esriGeometry.x = gcGeometriesToConvert[0].coordinates[0];                esriGeometry.y = gcGeometriesToConvert[0].coordinates[1];            }        } else {            esriGeometry[esriGeomInfo.geomHolder] = [];            for (i = 0; i < gcGeometriesToConvert.length; i++) {                coords = gcCoordinatesToEsriCoordinates(gcGeometriesToConvert[i]);                for (g = 0; g < coords.length; g++) {                    esriGeometry[esriGeomInfo.geomHolder].push(coords[g]);                }            }        }        return esriGeometry;    }    /*Converts GeoJSON feature to ESRI REST Feature.     Input parameter is a GeoJSON Feature object*/    function gcFeatureToEsriFeature(gcFeature) {        var esriFeat,            prop,            esriAttribs;        if (gcFeature) {            esriFeat = {};            if (gcFeature.geometry) {                esriFeat.geometry = gcGeometryToEsriGeometry(gcFeature.geometry);            }            if (gcFeature.properties) {                esriAttribs = {};                for (prop in gcFeature.properties) {                    esriAttribs[prop] = gcFeature.properties[prop];                }                esriFeat.attributes = esriAttribs;            }        }        return esriFeat;    }    /*Converts GeoJSON FeatureCollection, Feature, or Geometry     to ESRI Rest Featureset, Feature, or Geometry*/    gCon.toEsri = function(geoJsonObject) {        var outObj,            i,            gcFeats,            esriFeat;        if (geoJsonObject){            if (geoJsonObject.type === "FeatureCollection"){                outObj = {                    features: []                };                gcFeats = geoJsonObject.features;                for (i = 0; i < gcFeats.length; i++) {                    esriFeat = gcFeatureToEsriFeature(gcFeats[i]);                    if (esriFeat) {                        outObj.features.push(esriFeat);                    }                }            }            else if (geoJsonObject.type === "Feature"){                outObj = gcFeatureToEsriFeature(geoJsonObject);            }            else{                outObj = gcGeometryToEsriGeometry(geoJsonObject);            }        }        return outObj;    };    return gCon;}

实现后效果如下：

最后附上capital.geojson的内容：

{"type": "FeatureCollection","features": [{ "type": "Feature", "id": 0, "properties": { "name": "乌鲁木齐", "id": 10.000000, "lon": 87.576079, "lat": 43.782225, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 87.576079383021181, 43.782225203649105 ] } },{ "type": "Feature", "id": 1, "properties": { "name": "拉萨", "id": 11.000000, "lon": 91.163218, "lat": 29.710560, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 91.163217897611261, 29.710559728178374 ] } },{ "type": "Feature", "id": 2, "properties": { "name": "西宁", "id": 12.000000, "lon": 101.797439, "lat": 36.593725, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 101.79743904230159, 36.59372482860072 ] } },{ "type": "Feature", "id": 3, "properties": { "name": "兰州", "id": 13.000000, "lon": 103.584421, "lat": 36.119175, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 103.58442065913421, 36.11917453434188 ] } },{ "type": "Feature", "id": 4, "properties": { "name": "成都", "id": 14.000000, "lon": 104.035634, "lat": 30.714315, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 104.03563440326465, 30.714314809962257 ] } },{ "type": "Feature", "id": 5, "properties": { "name": "重庆", "id": 15.000000, "lon": 106.519225, "lat": 29.479073, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 106.51922502209845, 29.479073225153105 ] } },{ "type": "Feature", "id": 6, "properties": { "name": "贵阳", "id": 16.000000, "lon": 106.668183, "lat": 26.457486, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 106.66818338058295, 26.457485617599374 ] } },{ "type": "Feature", "id": 7, "properties": { "name": "昆明", "id": 17.000000, "lon": 102.726915, "lat": 24.969568, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 102.72691472988386, 24.969568444466436 ] } },{ "type": "Feature", "id": 8, "properties": { "name": "银川", "id": 18.000000, "lon": 106.167324, "lat": 38.598593, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 106.16732429995059, 38.598592562909062 ] } },{ "type": "Feature", "id": 9, "properties": { "name": "西安", "id": 19.000000, "lon": 108.967213, "lat": 34.276221, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 108.96721346583659, 34.276221246005349 ] } },{ "type": "Feature", "id": 10, "properties": { "name": "南宁", "id": 20.000000, "lon": 108.234036, "lat": 22.748502, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 108.23403628821811, 22.748502136254036 ] } },{ "type": "Feature", "id": 11, "properties": { "name": "海口", "id": 21.000000, "lon": 110.346274, "lat": 19.970150, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 110.34627437896368, 19.970150077576061 ] } },{ "type": "Feature", "id": 12, "properties": { "name": "广州", "id": 22.000000, "lon": 113.226755, "lat": 23.183277, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 113.22675511608018, 23.183277095857289 ] } },{ "type": "Feature", "id": 13, "properties": { "name": "长沙", "id": 23.000000, "lon": 112.947996, "lat": 28.170082, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 112.94799576419183, 28.170081880824668 ] } },{ "type": "Feature", "id": 14, "properties": { "name": "南昌", "id": 24.000000, "lon": 115.893762, "lat": 28.652529, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 115.89376225263823, 28.652528581920564 ] } },{ "type": "Feature", "id": 15, "properties": { "name": "福州", "id": 25.000000, "lon": 119.246798, "lat": 26.070956, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 119.24679821001271, 26.07095583016066 ] } },{ "type": "Feature", "id": 16, "properties": { "name": "台北", "id": 26.000000, "lon": 121.503585, "lat": 25.008476, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 121.50358485991021, 25.008475846011745 ] } },{ "type": "Feature", "id": 17, "properties": { "name": "杭州", "id": 27.000000, "lon": 120.183062, "lat": 30.330742, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 120.18306242469987, 30.330742397778341 ] } },{ "type": "Feature", "id": 18, "properties": { "name": "上海", "id": 28.000000, "lon": 121.449713, "lat": 31.253514, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 121.44971306145047, 31.253514397685105 ] } },{ "type": "Feature", "id": 19, "properties": { "name": "武汉", "id": 29.000000, "lon": 114.216652, "lat": 30.579401, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 114.21665206389655, 30.579400651160647 ] } },{ "type": "Feature", "id": 20, "properties": { "name": "合肥", "id": 30.000000, "lon": 117.262334, "lat": 31.838495, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 117.26233421444691, 31.838494863931761 ] } },{ "type": "Feature", "id": 21, "properties": { "name": "南京", "id": 31.000000, "lon": 118.805714, "lat": 32.085164, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 118.80571398101925, 32.085164185755289 ] } },{ "type": "Feature", "id": 22, "properties": { "name": "郑州", "id": 32.000000, "lon": 113.651151, "lat": 34.746419, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 113.65115064151188, 34.746419209304378 ] } },{ "type": "Feature", "id": 23, "properties": { "name": "济南", "id": 33.000000, "lon": 117.048354, "lat": 36.608511, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 117.04835397414672, 36.608510842637969 ] } },{ "type": "Feature", "id": 24, "properties": { "name": "石家庄", "id": 34.000000, "lon": 114.478253, "lat": 38.033361, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 114.47825266281612, 38.033361247307013 ] } },{ "type": "Feature", "id": 25, "properties": { "name": "太原", "id": 35.000000, "lon": 112.483119, "lat": 37.798488, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 112.4831190608968, 37.798487801001173 ] } },{ "type": "Feature", "id": 26, "properties": { "name": "呼和浩特", "id": 36.000000, "lon": 111.842856, "lat": 40.895807, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 111.84285564844028, 40.895806530184856 ] } },{ "type": "Feature", "id": 27, "properties": { "name": "天津", "id": 37.000000, "lon": 117.351108, "lat": 38.925801, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 117.35110819484493, 38.925800640164205 ] } },{ "type": "Feature", "id": 28, "properties": { "name": "沈阳", "id": 38.000000, "lon": 123.296260, "lat": 41.801674, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 123.29626003649942, 41.801674462394054 ] } },{ "type": "Feature", "id": 29, "properties": { "name": "长春", "id": 39.000000, "lon": 125.261357, "lat": 43.982041, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 125.26135735800531, 43.982040844340744 ] } },{ "type": "Feature", "id": 30, "properties": { "name": "哈尔滨", "id": 40.000000, "lon": 126.567056, "lat": 45.693857, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 126.56705607814561, 45.693856553844213 ] } },{ "type": "Feature", "id": 31, "properties": { "name": "北京", "id": 41.000000, "lon": 116.068297, "lat": 39.892297, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 116.06829681327378, 39.892296888653789 ] } },{ "type": "Feature", "id": 32, "properties": { "name": "香港", "id": 42.000000, "lon": 114.093184, "lat": 22.428066, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 114.09318425169782, 22.428065990916085 ] } },{ "type": "Feature", "id": 33, "properties": { "name": "澳门", "id": 43.000000, "lon": 113.552554, "lat": 22.184710, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 113.55255358053526, 22.184709710970235 ] } },{ "type": "Feature", "id": 34, "properties": { "name": null, "id": 44.000000, "lon": 99.584912, "lat": 40.657524, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 99.58491164397843, 40.657523622631167 ] } },{ "type": "Feature", "id": 35, "properties": { "name": null, "id": 45.000000, "lon": 97.988779, "lat": 33.563385, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 97.98877873041215, 33.563385489660234 ] } },{ "type": "Feature", "id": 36, "properties": { "name": null, "id": 46.000000, "lon": 88.568590, "lat": 35.839041, "heat": null }, "geometry": { "type": "Point", "coordinates": [ 88.568590370550467, 35.839040726871893 ] } }]}