解析 GML 编码的 WFS 响应 XML 文件

Question

我需要一些帮助，从这个GML编码的WMS响应XML文件中获取天气细节温度等。这是我从气象服务中获得的，该服务通过 Web 目录服务 (CSW(、Web 地图服务 (WMS( 和 Web 要素服务 (WFS( 提供开放数据。与 JSON/XML 不同，我不知道这个文件中发生了什么。请为 Swift 3 提供一些解决方案。

<?xml version="1.0" encoding="UTF-8"?>
<wfs:FeatureCollection
timeStamp="2017-07-31T15:48:01Z"
numberMatched="1"
numberReturned="1"
xmlns:wfs="http://www.opengis.net/wfs/2.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xlink="http://www.w3.org/1999/xlink"
xmlns:om="http://www.opengis.net/om/2.0"
xmlns:omso="http://inspire.ec.europa.eu/schemas/omso/3.0"
xmlns:ompr="http://inspire.ec.europa.eu/schemas/ompr/3.0"
xmlns:gml="http://www.opengis.net/gml/3.2"
xmlns:gmd="http://www.isotc211.org/2005/gmd"
xmlns:gco="http://www.isotc211.org/2005/gco"
xmlns:swe="http://www.opengis.net/swe/2.0"
xmlns:gmlcov="http://www.opengis.net/gmlcov/1.0"
xmlns:sam="http://www.opengis.net/sampling/2.0"
xmlns:sams="http://www.opengis.net/samplingSpatial/2.0"
xmlns:target="http://xml.fmi.fi/namespace/om/atmosphericfeatures/1.0"
xsi:schemaLocation="http://www.opengis.net/wfs/2.0 http://schemas.opengis.net/wfs/2.0/wfs.xsd
http://www.opengis.net/gmlcov/1.0 http://schemas.opengis.net/gmlcov/1.0/gmlcovAll.xsd
http://www.opengis.net/sampling/2.0 http://schemas.opengis.net/sampling/2.0/samplingFeature.xsd
http://www.opengis.net/samplingSpatial/2.0 http://schemas.opengis.net/samplingSpatial/2.0/spatialSamplingFeature.xsd
http://www.opengis.net/swe/2.0 http://schemas.opengis.net/sweCommon/2.0/swe.xsd
http://inspire.ec.europa.eu/schemas/omso/3.0 http://inspire.ec.europa.eu/schemas/omso/3.0/SpecialisedObservations.xsd
http://inspire.ec.europa.eu/schemas/ompr/3.0 http://inspire.ec.europa.eu/schemas/ompr/3.0/Processes.xsd
http://xml.fmi.fi/namespace/om/atmosphericfeatures/1.0 http://xml.fmi.fi/schema/om/atmosphericfeatures/1.0/atmosphericfeatures.xsd">
<wfs:member>
<omso:GridSeriesObservation gml:id="WFS-l9pen.SrlipXUb8ZfAc8nS2h_8.JTowuYWbbpdOs2_llx4efR060aeWzDtdOufXlmw48rp1w36d3R0629dnTTw36d3THv7ZeWHPlhaWLLn07qmnbltQ_wp37hjvCY2PlzrUi0Kcd06aMmrhnZd2Spp25bUP8KhE4V2nBm07sk7Lh5ZefSth2ackhmZ8u_Tk51mNmbRy2ZujXl899_LJf39svLvy09MOLZliaWzL2y7KnnhlqZmzfjw7MtambTfjSV3XpmcNbbh8RNPPph3Y8tK1dCA1tunnz07s9TL46VjTsM5lbd.TLsrM0aeWzDtZXDDyw7a1I.XfwkZdOfR0rWqZdvDLyw9OvLLWhQ5ZefPryy1oSOu3Tk09PNbVfTuyRNPLLj6ad.6tavp3ZKfDLlyTadZ1fTuyVZtOs6vp3ZK02nWtNw.NO3rtr6d2StCvp3ZI_Xn0rQiZe9Dfp3dK3qm_ph2Q9m_rkh7.2XlW5Xy4emjLyp.duLfsZ1tTN_eHs39ckPf2y8q4JuXJp67Yezf1yQ9_bLyrckac.iHs39ckPf2y8q3qHLLj08NPTD0079zHRXNQ5Zcenhp6Yemnfug7d_Xd0r2pYcmnD00790fZvxYdkHHj67euzD00791d1LDk04emnfumV4OPH129dmHpp37qwwqWHJpw9NO_dOy9KfXlmw48syvBx4.u3rsw9NO_dWGFSw5NOHpp37p2XpT68s2HHlp14OPH129dmHpp37q.KWHJpw9NO_dE05s3Xnlg48fXb12YemnfubnPpv5ZcnHrl5eb.nJXmFm26XTrNv5ZceHn0dOtGnlsw7XTrn15ZsOPK6dcN.nd0dOtvXZ008N.nd0x7.2Xlhz5Wh007ctPpl4T8hNDpp25bW_dlrGq1IYA-">
<om:phenomenonTime>
<gml:TimePeriod gml:id="time-interval-1-1">
<gml:beginPosition>2017-07-31T16:00:00Z</gml:beginPosition>
<gml:endPosition>2017-08-02T03:00:00Z</gml:endPosition>
</gml:TimePeriod>
</om:phenomenonTime>
<om:resultTime>
<gml:TimeInstant gml:id="time-1-1">
<gml:timePosition>2017-07-31T12:00:00Z</gml:timePosition>
</gml:TimeInstant>
</om:resultTime>
<om:procedure xlink:href="http://xml.fmi.fi/inspire/process/hirlam"/>
<om:parameter>
<om:NamedValue>
<om:name xlink:href="http://xml.fmi.fi/inspire/process/hirlam"/>
<om:value>
<gml:TimeInstant gml:id="analysis-time-1-1">
<gml:timePosition>2017-07-31T12:00:00Z</gml:timePosition>
</gml:TimeInstant>
</om:value>
</om:NamedValue>
</om:parameter>
<om:observedProperty  xlink:href="http://data.fmi.fi/fmi-apikey/e35dc8fd-a855-4db5-a327-418120f64a86/meta?observableProperty=forecast&amp;param=GeopHeight,Temperature,Pressure,Humidity,WindDirection,WindSpeedMS,WindUMS,WindVMS,MaximumWind,WindGust,DewPoint,TotalCloudCover,WeatherSymbol3,LowCloudCover,MediumCloudCover,HighCloudCover,Precipitation1h,PrecipitationAmount,RadiationGlobalAccumulation,RadiationLWAccumulation,RadiationNetSurfaceLWAccumulation,RadiationNetSurfaceSWAccumulation,RadiationDiffuseAccumulation&amp;language=eng"/>
<om:featureOfInterest>
<sams:SF_SpatialSamplingFeature gml:id="enn-s-1-1-">
<sam:sampledFeature>
<target:LocationCollection gml:id="sampled-target-1-1">
<target:member>
<target:Location gml:id="forloc-geoid-634963-pos">
<gml:identifier codeSpace="http://xml.fmi.fi/namespace/stationcode/geoid">634963</gml:identifier>
<gml:name codeSpace="http://xml.fmi.fi/namespace/locationcode/name">Tampere</gml:name>
<gml:name codeSpace="http://xml.fmi.fi/namespace/locationcode/geoid">634963</gml:name>
<target:representativePoint xlink:href="#point-634963"/>
<target:country codeSpace="http://xml.fmi.fi/namespace/location/country">Finland</target:country>
<target:timezone>Europe/Helsinki</target:timezone>
<target:region codeSpace="http://xml.fmi.fi/namespace/location/region">Finland</target:region>              
</target:Location></target:member>
</target:LocationCollection>
</sam:sampledFeature>
<sams:shape>
<gml:MultiPoint gml:id="sf-1-1-">
<gml:pointMembers>  
<gml:Point gml:id="point-634963" srsName="http://www.opengis.net/def/crs/EPSG/0/4258" srsDimension="2">
<gml:name>Tampere</gml:name>
<gml:pos>61.49911 23.78712 </gml:pos>
</gml:Point>
</gml:pointMembers>
</gml:MultiPoint>
</sams:shape>
</sams:SF_SpatialSamplingFeature>
</om:featureOfInterest>
<om:result>
<gmlcov:MultiPointCoverage gml:id="mpcv-1-1">
<gml:domainSet>
<gmlcov:SimpleMultiPoint gml:id="mp-1-1" srsName="http://xml.fmi.fi/gml/crs/compoundCRS.php?crs=4258&amp;time=unixtime" srsDimension="3">
<gmlcov:positions>
61.49911 23.78712  1501516800
61.49911 23.78712  1501520400
61.49911 23.78712  1501524000
61.49911 23.78712  1501527600
61.49911 23.78712  1501531200
</gmlcov:positions>
</gmlcov:SimpleMultiPoint>
</gml:domainSet>
<gml:rangeSet>
<gml:DataBlock>
<gml:rangeParameters/>
<gml:doubleOrNilReasonTupleList>
113.01 18.26 1007.03 92.74 259.0 3.79 
113.01 17.79 1007.48 90.02 250.0 3.04 
113.01 17.13 1007.82 93.62 229.0 2.19 
113.01 16.42 1008.18 95.53 216.0 2.26 
113.01 15.9 1008.89 97.09 211.0 2.74 
</gml:doubleOrNilReasonTupleList>
</gml:DataBlock>
</gml:rangeSet>
<gml:coverageFunction>
<gml:CoverageMappingRule>
<gml:ruleDefinition>Linear</gml:ruleDefinition>
</gml:CoverageMappingRule>
</gml:coverageFunction>
<gmlcov:rangeType>
<swe:DataRecord>
<swe:field name="GeopHeight"  xlink:href="http://"/>
<swe:field name="Temperature"  xlink:href="http://"/>
<swe:field name="Pressure"  xlink:href="http://"/>
<swe:field name="Humidity"  xlink:href="http://"/>
<swe:field name="WindDirection"  xlink:href="http://"/>
<swe:field name="WindSpeedMS"  xlink:href="http://"/>
</swe:DataRecord>
</gmlcov:rangeType>
</gmlcov:MultiPointCoverage>
</om:result>
</omso:GridSeriesObservation>
</wfs:member>
</wfs:FeatureCollection>

Answer 1

我不能帮助你快速，但我也许可以指出你如何阅读这个文件：

你基本上需要的是这三个元素：

<gmlcov:positions>
61.49911 23.78712  1501516800
61.49911 23.78712  1501520400
61.49911 23.78712  1501524000
61.49911 23.78712  1501527600
61.49911 23.78712  1501531200
</gmlcov:positions>
<gml:doubleOrNilReasonTupleList>
113.01 18.26 1007.03 92.74 259.0 3.79 
113.01 17.79 1007.48 90.02 250.0 3.04 
113.01 17.13 1007.82 93.62 229.0 2.19 
113.01 16.42 1008.18 95.53 216.0 2.26 
113.01 15.9 1008.89 97.09 211.0 2.74 
</gml:doubleOrNilReasonTupleList>
<swe:DataRecord>
<swe:field name="GeopHeight"  xlink:href="http://"/>
<swe:field name="Temperature"  xlink:href="http://"/>
<swe:field name="Pressure"  xlink:href="http://"/>
<swe:field name="Humidity"  xlink:href="http://"/>
<swe:field name="WindDirection"  xlink:href="http://"/>
<swe:field name="WindSpeedMS"  xlink:href="http://"/>
</swe:DataRecord>

第一个告诉您测量的位置和时间：

61.49911 23.78712 1501516800

Latitude: 61.49911
Longitude: 23.7812
Unixtime:   1501516800 --> which translates to: Mon Jul 31 16:00:00 2017 UTC

第二个是实际的测量数据，第三个给你测量的含义。
因此，这是您在第一次测量时得到的结果：

GeopHeight | Temperature | Pressure | Humidity | WindDirection | WindSpeedMs
113.01     | 18.26       | 1007.03  | 92.74    | 259.0         | 3.79

我希望这有所帮助。