var point = new ol.geom.Point(ol.proj.fromLonLat([87.646 ,40.309], 'EPSG:4326'));
var lineT = new ol.geom.LineString([[87.646 ,40.309], [87.646 ,40.323],[87.6506 ,40.324]]);
var circleFeature = new ol.geom.Circle([87.646 ,40.309], 0.05);
var polygon = new ol.geom.Polygon.fromCircle(circleFeature); //圆转为多边形后才能进行分析
//多边形分析
var polygon = new ol.geom.Polygon([[
   [84.03,40.74],
   [87.37,40.72],
   [86.24,39.78],
   [84.03,40.74]
]]);

var featureRequest = new ol.format.WFS().writeGetFeature({
   srsName: 'EPSG:4326',//坐标系统
   featureNS: 'pg',//命名空间 URI
   featurePrefix: 'pg',//工作区名称
   featureTypes: ['pol_salt_v'],//查询图层，可以是同一个工作区下多个图层，逗号隔开
   outputFormat: 'application/json',
   //filter: ol.format.filter.intersects("geom",polygon)//前者是属性名，后者是对应值 单条件过滤
   filter: ol.format.filter.and(   //多条件过率
      ol.format.filter.equalTo('at', '2020'),
      ol.format.filter.intersects("geom", 点线面的要素)
   )
});

fetch('http://192.168.0.164:5081/geoserver/' + 'wfs', {//geoserver wfs地址如localhost:8080/geoserver/wfs，
   method: 'POST',
   body: new XMLSerializer().serializeToString(featureRequest)
}).then(function(response) {
   console.info(response);
   console.info(response.json);
   return response.json();
}).then(function(json) {
   console.info(json);
   var pro=json.features[0].properties;
   console.info(pro);
}