ultimate-geojson

ultimate-geojeson is the ultimate GeoJSON java library to generate & parse GeoJSON and to do geospatial operations on geometry objects.

Conversion from JTS (org.locationtech.jts) to ugeojson DTO model and vice versa is supported now.

Table of Contents

• ultimate-geojson
  • About GeoJSON
  • Data Models
  • How To Parse GeoJSON
  • How To Build (generate) GeoJSON
    • PointBuilder
    • LineStringBuilder
    • PolygonBuilder
    • MultiPointBuilder
    • MultiLineStringBuilder
    • MultiPolygonBuilder
    • GeometryCollectionBuilder
    • FeatureBuilder
    • FeatureCollectionBuilder
    • UltimateGeoJSONBuilder
  • JtsUGeojsonConversionUtil
  • How To Generate Circle GeoJSON
  • How To Generate Arc GeoJSON
  • Built With
  • Authors
  • License
  • Acknowledgments

About GeoJSON

GeoJSON is a format for encoding a variety of geographic data structures.

ultimate-geojeson uses The GeoJSON Specification (RFC 7946)) for its implementation.

You can test and view results generated GeoJSON strings on following sites:

• http://geojson.io/
• http://jsfiddle.net/asnyder14/9dxbcr4f/embedded/result/
• http://dev.openlayers.org/examples/vector-formats.html

Demo of ultimate-geojson Usage

Data Models

ultimate-geojeson represents GeoJSON objects as pojo data transfer objects(Dto).

• PositionDto
• PointDto
• LineStringDto
• PolygonDto
• MultiPointDto
• MultiLineStringDto
• MultiPolygonDto
• GeometryCollectionDto
• FeatureDto
• FeatureCollectionDto

How To Parse GeoJSON

You can use UltimateGeoJSONParser class

String featureGeoJson = "{\"type\": \"Feature\", "
				+ " \"bbox\": [-10.0, -10.0, 10.0, 10.0],"
				+ " \"properties\": {}, "
				+ " \"geometry\":  {        \"type\": \"Point\",       \"coordinates\": [14.244158,   \n47.149861, 0.7890780]    } }";

GeoJSONObjectDto geoJSONObjectDto = UltimateGeoJSONParser.getInstance().parse(featureGeoJson);
FeatureDto feature = (FeatureDto) geoJSONObjectDto;
// prints Point
System.out.println(feature.getGeometry().getGeoJSONObjectType());

How To Build (generate) GeoJSON

For each GeoJSON object type, there is a builder class to convert model dto classes to GeoJSON String. For example; PointBuilder, PolygonBuilder etc...

Alternatively, you can use UltimateGeoJSONBuilder class for all types.

PointBuilder

PointDto point = new PointDto(101.2471,37.2368);
String geometryGeoJSON = PointBuilder.getInstance().toGeoJSON(point);

Output:

{
"type": "Point",
"coordinates": [101.2471, 37.2368]
}

LineStringBuilder

LineStringDto lineString = new LineStringDto();
List<PositionDto> positions = new ArrayList<>();
positions.add(new PositionDto(32.123,24.587));
positions.add(new PositionDto(36.1478,29.3645));
lineString.setPositions(positions);
		
String geometryGeoJSON = LineStringBuilder.getInstance().toGeoJSON(lineString);

Output:

{
"type": "LineString",
"coordinates": [
 [32.123, 24.587],
 [36.1478, 29.3645]
]
}

PolygonBuilder

PolygonDto polygon = new PolygonDto();
LineStringDto lineString1 = new LineStringDto(Arrays.asList(new PositionDto(32.123, 24.587),new PositionDto(36.1478, 29.3645),new PositionDto(44.44,45,55)));
				
polygon.setLinearRings(Arrays.asList(lineString1));
String geometryGeoJSON = PolygonBuilder.getInstance().toGeoJSON(polygon);

Output:

{
"type": "Polygon",
"coordinates": [
[
 [32.123, 24.587],
 [36.1478, 29.3645],
 [44.44, 45.0, 55.0],
 [32.123, 24.587]
]
]
}

MultiPointBuilder

MultiPointDto multiPoint = new MultiPointDto();
List<PositionDto> positions = new ArrayList<>();
positions.add(new PositionDto(32.123, 24.587));
positions.add(new PositionDto(36.1478, 29.3645));
multiPoint.setPositions(positions);
String geometryGeoJSON = MultiPointBuilder.getInstance().toGeoJSON(multiPoint);

Output:

{
"type": "MultiPoint",
"coordinates": [
[32.123, 24.587],
[36.1478, 29.3645]
]
}

MultiLineStringBuilder

MultiLineStringDto multiLine = new MultiLineStringDto();
LineStringDto lineString1 = new LineStringDto(Arrays.asList(new PositionDto(32.123, 24.587),new PositionDto(36.1478, 29.3645)));
LineStringDto lineString2 = new LineStringDto(Arrays.asList(new PositionDto(12.2365, -14.8987),new PositionDto(63.254, 28.778)));
		
multiLine.setLines(Arrays.asList(lineString1,lineString2));
		
String geometryGeoJSON = MultiLineStringBuilder.getInstance().toGeoJSON(multiLine);

Output:

{
"type": "MultiLineString",
"coordinates": [
[
 [32.123, 24.587],
 [36.1478, 29.3645]
],
[
 [12.2365, -14.8987],
 [63.254, 28.778]
]
]
}

MultiPolygonBuilder

PolygonDto polygon = new PolygonDto();
LineStringDto lineString1 = new LineStringDto(Arrays.asList(new PositionDto(32.123, 24.587),new PositionDto(36.1478, 29.3645)));
lineString1.getPositions().add(new PositionDto(44.44,45,55));
		
polygon.setLinearRings(Arrays.asList(lineString1));
 
MultiPolygonDto multiPolygon = new MultiPolygonDto();
multiPolygon.setPolygons(Arrays.asList(polygon));
	
String geometryGeoJSON = MultiPolygonBuilder.getInstance().toGeoJSON(multiPolygon);

Output:

{
"type": "MultiPolygon",
"coordinates": [
[
[
 [32.123, 24.587],
 [36.1478, 29.3645],
 [44.44, 45.0, 55.0],
 [32.123, 24.587]
]
]
]
}

GeometryCollectionBuilder

PointDto point = new PointDto(101.2471,37.2368);
LineStringDto line = new LineStringDto(Arrays.asList(new PositionDto(101.01, 58.0147),new PositionDto(24.014, 19.364)));
		
GeometryCollectionDto geometryCollection = new GeometryCollectionDto();
geometryCollection.setGeometries(Arrays.asList(point,line));
String geometryGeoJSON = GeometryCollectionBuilder.getInstance().toGeoJSON(geometryCollection);
System.out.println(geometryGeoJSON);

Output:

{
"type": "GeometryCollection",
"geometries": [{
"type": "Point",
"coordinates": [101.2471, 37.2368]
},{
"type": "LineString",
"coordinates": [
 [101.01, 58.0147],
 [24.014, 19.364]
]
}]
}

FeatureBuilder

FeatureDto feature = new FeatureDto();
LineStringDto lineString1 = new LineStringDto(Arrays.asList(new PositionDto(32.123, 24.587),new PositionDto(36.1478, 29.3645)));
feature.setGeometry(lineString1);
feature.setId("2423534545");
		
feature.setProperties("{}");
String featureGeoJSON = FeatureBuilder.getInstance().toGeoJSON(feature);
System.out.println(featureGeoJSON);

Output:

{
"type": "Feature",
"geometry": {
"type": "LineString",
"coordinates": [
 [32.123, 24.587],
 [36.1478, 29.3645]
]
},
"properties": {},
"id": 2423534545
}

FeatureCollectionBuilder

FeatureDto feature = new FeatureDto();
LineStringDto lineString1 = new LineStringDto(Arrays.asList(new PositionDto(32.123, 24.587),new PositionDto(36.1478, 29.3645)));
feature.setGeometry(lineString1);
feature.setId("2423534545");
feature.setProperties("{}");
		
FeatureDto feature2 = new FeatureDto();
LineStringDto lineString2 = new LineStringDto(Arrays.asList(new PositionDto(47.47, 59.457),new PositionDto(86.3698, 45.10471)));
feature2.setGeometry(lineString2);
feature2.setId("\"myFeatureId\"");
		
feature2.setProperties("{\"color\": \"red\"}");
FeatureCollectionDto featureCollection = new FeatureCollectionDto();
featureCollection.setFeatures(Arrays.asList(feature,feature2));
		
String featureCollectionGeoJSON = FeatureCollectionBuilder.getInstance().toGeoJSON(featureCollection);
System.out.println(featureCollectionGeoJSON);

Output:

{
"type": "FeatureCollection",
"features": [{
"type": "Feature",
"geometry": {
"type": "LineString",
"coordinates": [
 [32.123, 24.587],
 [36.1478, 29.3645]
]
},
"properties": {},
"id": 2423534545
},
{
"type": "Feature",
"geometry": {
"type": "LineString",
"coordinates": [
 [47.47, 59.457],
 [86.3698, 45.10471]
]
},
"properties": {"color": "red"},
"id": "myFeatureId"
}]
}

UltimateGeoJSONBuilder

You can use UltimateGeoJSONBuilder for all types.

FeatureDto feature = new FeatureDto();
LineStringDto lineString1 = new LineStringDto(Arrays.asList(new PositionDto(32.123, 24.587),new PositionDto(36.1478, 29.3645)));
feature.setGeometry(lineString1);
feature.setId("2423534545");
		
feature.setProperties("{}");
String featureGeoJSON = UltimateGeoJSONBuilder.getInstance().toGeoJSON(feature);

Output:

{
"type": "Feature",
"geometry": {
"type": "LineString",
"coordinates": [
 [32.123, 24.587],
 [36.1478, 29.3645]
]
},
"properties": {},
"id": 2423534545
}

JtsUGeojsonConversionUtil

You can use JtsUGeojsonConversionUtil class to convert org.locationtech.jts.geom.Geometry objects to ugeojson GeometryDto and vice versa.

Supported JTS geometries to convert

• org.locationtech.jts.geom.Coordinate <--> PositionDto
• org.locationtech.jts.geom.Point <--> PointDto
• org.locationtech.jts.geom.LineString <--> LineStringDto
• org.locationtech.jts.geom.Polygon <--> PolygonDto
• org.locationtech.jts.geom.MultiPoint <--> MultiPointDto
• org.locationtech.jts.geom.MultiLineString <--> MultiLineStringDto
• org.locationtech.jts.geom.MultiPolygon <--> MultiPolygonDto
• org.ugeojson.model.geometry.GeometryCollectionDto <--> GeometryCollectionDto

jts-core artifact of org.locationtech.jts group Maven dependency is added as provided type in this library. So, whenever you want to use this conversion util, you need to add that dependency to your project. see https://mvnrepository.com/artifact/org.locationtech.jts/jts-core

Example usage

JtsUGeojsonConversionUtil jtsUGeojsonConversionUtil = new JtsUGeojsonConversionUtil();

// to ugeojson
PolygonDto polygonDto = jtsUGeojsonConversionUtil.toPolygonDto(someJtsPolygonInstance);

// to JTS
Polygon jtsPolygon = jtsUGeojsonConversionUtil.toJtsPolygon(polygonDto);

// Generic conversion support
Geometry jtsGeometry = jtsUGeojsonConversionUtil.toJtsGeometry(polygonDto);

GeometryDto geometryDto = jtsUGeojsonConversionUtil.toGeometryDto(jtsGeometry);

How To Generate Circle GeoJSON

Circular drawing capabilities are in ugeojson-math module. You can use CircularDrawingAlgorithmImpl class to generate circle points given center point and radius.

For example, Let's generate a circle with 10000 m radius.

CircularDrawingAlgorithmImpl circleDrawer = new CircularDrawingAlgorithmImpl();
List<PositionDto> circlePoints = circleDrawer.getCirclePositions(new PositionDto(35,38), 10000.0);
		
UltimateGeoJSONFactory factory = new UltimateGeoJSONFactory();
PolygonDto circleAsPolygon = factory.createPolygon(circlePoints);

String geoJSON = UltimateGeoJSONBuilder.getInstance().toGeoJSON(circleAsPolygon);

You can see the resulting circle on any geojson viewer.

How To Generate Arc GeoJSON

To generate pie slice like arcs, we give center point, starting bearing angle and ending bearing angle in degrees. Let's draw an arc of first 45 degrees of the circle we drow above.

CircularDrawingAlgorithmImpl circleDrawer = new CircularDrawingAlgorithmImpl();
PositionDto center = new PositionDto(35,38);
List<PositionDto> arcPositions = circleDrawer.getArcPositions(center, 10000, 0, 45);
		
UltimateGeoJSONFactory factory = new UltimateGeoJSONFactory();
PolygonDto polygon = factory.createPolygon(arcPositions);
		
String geoJSON = UltimateGeoJSONBuilder.getInstance().toGeoJSON(polygon);

Built With

• Maven - Dependency Management

Authors

• Murat Öksüzer - Initial work - mokszr (Personel Site: http://www.muratoksuzer.com/) Youtube Channel: https://www.youtube.com/@muratoksuzer

See also the list of contributors who participated in this project.

License

This project is licensed under the MIT License - see the LICENSE file for details

Acknowledgments

• Hat tip to anyone who's code was used