https://github.com/workingdog/kmltogeojson

Converts Kml to GeoJSON format
https://github.com/workingdog/kmltogeojson

geojson kml scala

Last synced: about 3 hours ago
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Converts Kml to GeoJSON format

• Host: GitHub
• URL: https://github.com/workingdog/kmltogeojson
• Owner: workingDog
• License: other
• Created: 2015-11-02T03:09:57.000Z (about 9 years ago)
• Default Branch: master
• Last Pushed: 2020-03-20T03:59:08.000Z (over 4 years ago)
• Last Synced: 2024-01-30T13:37:36.107Z (9 months ago)
• Topics: geojson, kml, scala
• Language: Scala
• Homepage:
• Size: 51.7 MB
• Stars: 12
• Watchers: 3
• Forks: 3
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: changes.md
  • License: license.txt

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README

        
# Convert Kml to GeoJSON format 

This application **KmlToGeojson**, converts Kml and Kmz files into a GeoJSON representation. 

[Kml](https://developers.google.com/kml/documentation/kmlreference) is used in Google Earth to display 

various geographic elements, such as; images, place marks, polygon shapes, and so on.

Similarly [GeoJSON](http://geojson.org/) is a format for encoding a variety of geographic data structures.

This scala application uses the [scalakml library](https://github.com/workingDog/scalakml) and 

the [play-geojson library](https://github.com/jroper/play-geojson) to convert Kml to GeoJSON format.

 

## Kml to GeoJSON mapping

Currently the following mapping is implemented.

    Kml object -> list of GeoJSON object

    Kml Folder -> GeoJSON FeatureCollection

    Kml Document -> GeoJSON FeatureCollection

    Kml MultiGeometry -> GeoJSON GeometryCollection

    Kml Placemark -> GeoJSON Feature

    Kml Point -> GeoJSON Point

    Kml LineString -> GeoJSON LineString

    Kml LinearRing -> GeoJSON LineString

    Kml Polygon -> GeoJSON Polygon

    Kml LatLonAltBox -> GeoJSON bbox

The GeoJSON Feature "properties" are generated from the following Kml elements:

    name, description, address, phoneNumber, styleUrl, visibility, open, 

    timeSpan (begin and end), timeStamp (when),

    extendedData (displayName, name, value), altitudeMode, extrude

 

The Kml "id" attribute is converted to the GeoJSON Feature "id".

Everything else is ignored.

 

Only [WGS84](https://en.wikipedia.org/wiki/World_Geodetic_System) coordinate reference system 

is supported and all longitudes and latitudes are in decimal degrees.

## Installation and packaging

The easiest way to compile and package the application from source is to use [SBT](http://www.scala-sbt.org/).

To package the application and all its dependencies into a single jar file type:

    sbt assembly

This will produce "kmltogeojson-1.2.jar" in the "./target/scala-2.13" directory.

#### For convenience a **kmltogeojson-1.2.jar** file is in the "distrib" directory ready for use.

## Usage

Once you have the jar file, simply type at the prompt:

 

    java -jar kmltogeojson-1.2.jar kml_file.kml geojson_file.geojson

 

where "kml_file.kml" is the Kml file you want to convert, and "geojson_file.geojson" is the destination file 

with the [GeoJSON](http://geojson.org/) format results. If the "geojson_file.geojson" is absent, the output is directed to the console.

 

You can also use this library in your scala code. First add the following dependency to your build.sbt file:

    libraryDependencies += "com.github.workingDog" %% "kmltogeojson" % "1.2"

Then, for example:

    object TestGeoJson {

      def main(args: Array[String]) {

        // read a kml document from file

        val kml = new KmlFileReader().getKmlFromFile("./kml-files/Sydney.kml")

        // convert the kml document to geojson format

        val geojson = KmlConverter().toGeoJson(kml)

        // print the geojson objects

        geojson.foreach(obj => println(Json.prettyPrint(Json.toJson(obj))))

      }

    }

   

The **KmlConverter.scala** has one generic method **toGeoJson()** that takes any of the implemented Kml objects. 

See also "TestGeoJson".

 

## Dependencies

Depends on the scala [scalakml library](https://github.com/workingDog/scalakml), 

and on the scala [play-geojson library](https://github.com/jroper/play-geojson).

## References

 

1) OGC 07-147r2 Version: 2.2.0, Category: OGC Standard, Editor: Tim Wilson, at http://www.opengeospatial.org/standards/kml

2) Google developers KML Reference, at https://developers.google.com/kml/documentation/kmlreference

3) GeoJSON reference document, at http://geojson.org/geojson-spec.html

## Status

Stable.

Using Scala 2.13.1, Java 11 and SBT-1.3.8.