從Java中的KML文件中提取座標

Question

我想解析Java中的Kml文件。因爲我需要獲取地標的座標，在java中生成poligon並使用它。

但我的問題是，我正在使用JAK這個庫來解析它，並且我無法提取我想要的信息（我在官方頁面閱讀了「幫助」，但是我沒有「噸發現緊靠我的問題，任何幫助）

我試圖做這樣的事情：

final Kml kml = Kml.unmarshal(new File("C:/Users/A556520/Documents/Proyectos/GeoFencing/res/labasa.kml")); 
final Document document = (Document)kml.getFeature();  
List<Feature> listafeatures = document.getFeature();   

但在這一點上，我不知道如何提取的座標。

我試圖解析該文件是這個：la basa

Answer 1

繼javadocs（unofficial），您需要檢查 - 用instanceof - 每個Feature是否是Placemark，如果是投給它，並得到Geometry本身需要檢查它是否是Polygon，如果是的話就投給它。此後，路徑座標如下（就像它進來的KML文件）：

getOuterBoundaryIs > getlinearRing > getCoordinates 

這裏是如何看起來像代碼：

@Test 
public void parseKml() { 
    String src = "misctests/stackoverflow/kml/labasa.kml"; 
    InputStream is = getClass().getClassLoader().getResourceAsStream(src); 
    Assert.assertNotNull(is); 
    Kml kml = Kml.unmarshal(is); 
    Feature feature = kml.getFeature(); 
    parseFeature(feature); 
} 

private void parseFeature(Feature feature) { 
    if(feature != null) { 
     if(feature instanceof Document) { 
      Document document = (Document) feature; 
      List<Feature> featureList = document.getFeature(); 
      for(Feature documentFeature : featureList) { 
       if(documentFeature instanceof Placemark) { 
        Placemark placemark = (Placemark) documentFeature; 
        Geometry geometry = placemark.getGeometry(); 
        parseGeometry(geometry); 
       } 
      } 
     } 
    } 
} 

private void parseGeometry(Geometry geometry) { 
    if(geometry != null) { 
     if(geometry instanceof Polygon) { 
      Polygon polygon = (Polygon) geometry; 
      Boundary outerBoundaryIs = polygon.getOuterBoundaryIs(); 
      if(outerBoundaryIs != null) { 
       LinearRing linearRing = outerBoundaryIs.getLinearRing(); 
       if(linearRing != null) { 
        List<Coordinate> coordinates = linearRing.getCoordinates(); 
        if(coordinates != null) { 
         for(Coordinate coordinate : coordinates) { 
          parseCoordinate(coordinate); 
         } 
        } 
       } 
      } 
     } 
    } 
} 

private void parseCoordinate(Coordinate coordinate) { 
    if(coordinate != null) { 
     System.out.println("Longitude: " + coordinate.getLongitude()); 
     System.out.println("Latitude : " + coordinate.getLatitude()); 
     System.out.println("Altitude : " + coordinate.getAltitude()); 
     System.out.println(""); 
    } 
} 

Answer 2

跨越此帖一，所以這裏是我在我的應用程序中使用的函數代碼的一部分，以便從字符串kmlText中提取地點標記名稱&座標。

if (kmlText != null & kmlText.length() > 0) { 
    // Change case of relevant tags to match our search string case 
    kmlText = kmlText.replaceAll("(?i)<Placemark>", "<Placemark>") 
     .replaceAll("(?i)</Placemark>", "</Placemark>") 
     .replaceAll("(?i)<name>", "<name>") 
     .replaceAll("(?i)</name>", "</name>") 
     .replaceAll("(?i)<coordinates>", "<coordinates>") 
     .replaceAll("(?i)</coordinates>", "</coordinates>"); 
    // Get <Placemark> tag 
    String[] kmlPlacemarks = kmlText.split("</Placemark>"); 
    if (kmlPlacemarks.length > 0) { 
     for (Integer i = 0; i < kmlPlacemarks.length; i++) { 
      // Add '</Placemark>' to the end - actually not necessary 
      kmlPlacemarks[i] += "</Placemark>"; 
      if (kmlPlacemarks[i].indexOf("<Placemark>") > -1) 
       /* Trim front to start from '<Placemark>' 
       Otherwise additional tags may be in between leading 
       to parsing of incorrect values especially Name */ 
       kmlPlacemarks[i] = kmlPlacemarks[i].substring(kmlPlacemarks[i].indexOf("<Placemark>")); 
     } 
     String tmpPlacemarkName; 
     String tmpPlacemarkCoordinates; 
     for (String kmlPlacemark: kmlPlacemarks) 
      if ((kmlPlacemark.indexOf("<name>") > -1 && kmlPlacemark.indexOf("</name>") > -1) && 
        (kmlPlacemark.indexOf("<coordinates>") > -1 && kmlPlacemark.indexOf("</coordinates>") > -1)) { 
       tmpPlacemarkCoordinates = kmlPlacemark.substring(kmlPlacemark.indexOf("<coordinates>") + 13, kmlPlacemark.indexOf("</coordinates>")); 
       tmpPlacemarkName = kmlPlacemark.substring(kmlPlacemark.indexOf("<name>") + 6, kmlPlacemark.indexOf("</name>")); 
      } 
     } 
} 

Answer 3

感謝@ A4L這是一個真正的更新而這樣做改變了Groovy中相同的更更巧妙的方式，也嘗試更多類型比給出以及例子深挖一個文檔層中：

/** 
    * This starts the process and reads in the uk file 
    */ 
    public static void parseKml() { 
     def src = ServletContextHolder.servletContext.getRealPath("/KML/doc.kml") 
     InputStream is = new FileInputStream(src); 
     Kml kml = Kml.unmarshal(is); 
     Feature feature = kml.getFeature(); 
     parseFeature(feature); 
    } 

    /** 
    * This is step 2 of the process it figures out if it has a direct placemark mapping on kml 
    * or if this is part of some big folder structure 
    * @param feature 
    */ 
    public static void parseFeature(Feature feature) { 
     if(feature) { 
      if(feature instanceof Document) { 
       feature?.feature?.each { documentFeature-> 
        if(documentFeature instanceof Placemark) { 
         getPlacemark((Placemark) documentFeature) 
        } else if (documentFeature instanceof Folder) { 
         getFeatureList(documentFeature.feature) 
        } 
       } 
      } 
     } 
    } 


    /** 
    * This iterates over itself over and over again to gain access to placemarks within folders 
    * The uk map boundary was nested folders within folders 
    * @param features 
    * @return 
    */ 
    public static List<Feature> getFeatureList(List<Feature> features) { 
     features?.each { Feature f -> 
      if (f instanceof Folder) { 
       getFeatureList(f.getFeature()) 
      } else if (f instanceof Placemark) { 
       getPlacemark((Placemark) f) 
      } 
     } 
    } 

    /** 
    * This in short kicks off looking at a placemark it's name then parsing through each of its geometry points 
    * This controls the listener content or should I say builds it up from within this helper 
    * @param placemark 
    */ 
    public static void getPlacemark(Placemark placemark) { 
     Geometry geometry = placemark.getGeometry() 
     List results = parseGeometry(geometry) 
     GeoMapListener.update(placemark.name, results) 
    } 


    private static List parseGeometry(Geometry geometry) { 
     List results=[] 
     if(geometry != null) { 
      if(geometry instanceof Polygon) { 
       Polygon polygon = (Polygon) geometry; 
       Boundary outerBoundaryIs = polygon.getOuterBoundaryIs(); 
       if(outerBoundaryIs != null) { 
        LinearRing linearRing = outerBoundaryIs.getLinearRing(); 
        if(linearRing != null) { 
         List<Coordinate> coordinates = linearRing.getCoordinates(); 
         if(coordinates != null) { 
          for(Coordinate coordinate : coordinates) { 
           results << parseCoordinate(coordinate); 
          } 
         } 
        } 
       } 
      } else if (geometry instanceof LineString) { 
       LineString lineString = (LineString) geometry; 
       List<Coordinate> coordinates = lineString.getCoordinates(); 
       if (coordinates != null) { 
        for (Coordinate coordinate : coordinates) { 
         results << parseCoordinate(coordinate); 
        } 
       } 
      } 
     } 
     return results 
    } 

    private static Map parseCoordinate(Coordinate coordinate) { 
     Map results=[:] 
     if(coordinate) { 
      results.longitude= coordinate.longitude 
      results.latitude= coordinate.latitude 
      results.altitude= coordinate.altitude 
     } 
     return results 
    }