Select platform: [Android](https://developers.google.com/maps/documentation/android-sdk/utility/geojson.md.txt "View this page for the Android platform docs.") [iOS](https://developers.google.com/maps/documentation/ios-sdk/utility/geojson.md.txt "View this page for the iOS platform docs.") [JavaScript](https://developers.google.com/maps/documentation/javascript/datalayer.md.txt "View this page for the JavaScript platform docs.") 1. [Introduction](https://developers.google.com/maps/documentation/android-sdk/utility/geojson.md.txt#introduction) 2. [Add a GeoJsonLayer to your map](https://developers.google.com/maps/documentation/android-sdk/utility/geojson#add) 3. [Remove the GeoJsonLayer](https://developers.google.com/maps/documentation/android-sdk/utility/geojson#remove) 4. [Add and remove a GeoJsonFeature](https://developers.google.com/maps/documentation/android-sdk/utility/geojson#feature) 5. [Access the GeoJsonFeatures and their properties](https://developers.google.com/maps/documentation/android-sdk/utility/geojson#properties) 6. [Style the GeoJsonLayer and GeoJsonFeatures](https://developers.google.com/maps/documentation/android-sdk/utility/geojson#style) 7. [See the demo app](https://developers.google.com/maps/documentation/android-sdk/utility/geojson.md.txt#demo-app) ## Introduction [GeoJSON](http://geojson.org/) is an extension of the JSON data format and represents geographical data. Using this utility, you can store geographical features in GeoJSON format and render them as a layer on top of the map. To add and remove your GeoJSON data to and from the map, call `addLayerToMap()` and `removeLayerFromMap()` respectively. Similarly you can add and remove individual features by calling `addFeature()` and `removeFeature()` and passing in a `GeoJsonFeature` object. If you want to access the features, you can call `getFeatures()` to get an iterable of all ` GeoJsonFeature` objects that have been added to the layer. You can also set default styles to be applied to features before they are added to the layer, by calling `getDefaultPointStyle()`, `getDefaultLineStringStyle()` or ` getDefaultPolygonStyle()` and setting style options on each. Alternatively, you can set the style for an individual `GeoJsonFeature` by calling `setPointStyle()`, `setLineStringStyle()` or `setPolygonStyle()` on the feature and passing in the relevant style object. ## Add a GeoJsonLayer to your map To add a GeoJson layer to the map, first create an instance of a GeoJsonLayer class. There are two ways to instantiate the GeoJsonLayer. To import from a `JSONObject`, you need the following: - `GoogleMap` object where the layer is to be rendered - `JSONObject` containing the GeoJSON data to be added to the layer ### Kotlin ```kotlin val geoJsonData: JSONObject = // JSONObject containing the GeoJSON data val layer = GeoJsonLayer(map, geoJsonData) ``` ### Java ```java JSONObject geoJsonData = // JSONObject containing the GeoJSON data GeoJsonLayer layer = new GeoJsonLayer(map, geoJsonData); ``` To import from a local GeoJSON file you need the following: - `GoogleMap` object where the layer is to be rendered - Local resource file containing the GeoJSON data - `Context` object, which is required to open a local resource file ### Kotlin ```kotlin val layer = GeoJsonLayer(map, R.raw.geojson_file, context) ``` ### Java ```java GeoJsonLayer layer = new GeoJsonLayer(map, R.raw.geojson_file, context); ``` After you have created the `GeoJsonLayer`, call `addLayerToMap()` to add the imported data onto the map: ### Kotlin ```kotlin layer.addLayerToMap() ``` ### Java ```java layer.addLayerToMap(); ``` ## Remove the GeoJsonLayer Let's assume that you have added this layer ### Kotlin ```kotlin val geoJsonData: JSONObject = // JSONObject containing the GeoJSON data val layer = GeoJsonLayer(map, geoJsonData) ``` ### Java ```java JSONObject geoJsonData = // JSONObject containing the GeoJSON data GeoJsonLayer layer = new GeoJsonLayer(map, geoJsonData); ``` To clear the GeoJsonLayer, call `removeLayerFromMap()` ### Kotlin ```kotlin it.removeLayerFromMap() ``` ### Java ```java geoJsonLayer.removeLayerFromMap(); ``` ## Add and remove a GeoJsonFeature A feature in GeoJSON has the type "feature". It contains a geometry, a property member and optionally has a bounding box or an id. You can create `GeoJsonFeature` objects individually, and add them to the ` GeoJsonLayer`. Let's assume that you've created a feature containing a point at 0, 0 with one entry in its properties and no bounding box. ### Kotlin ```kotlin val point = GeoJsonPoint(LatLng(0.0, 0.0)) val properties = hashMapOf("Ocean" to "South Atlantic") val pointFeature = GeoJsonFeature(point, "Origin", properties, null) ``` ### Java ```java GeoJsonPoint point = new GeoJsonPoint(new LatLng(0, 0)); HashMap properties = new HashMap<>(); properties.put("Ocean", "South Atlantic"); GeoJsonFeature pointFeature = new GeoJsonFeature(point, "Origin", properties, null); ``` To add the feature to the layer, call `addFeature()` and pass in the feature to add. ### Kotlin ```kotlin layer.addFeature(pointFeature) ``` ### Java ```java layer.addFeature(pointFeature); ``` To remove a feature after adding it to the layer, call `removeFeature()` and pass in the feature to remove. ### Kotlin ```kotlin layer.removeFeature(pointFeature) ``` ### Java ```java layer.removeFeature(pointFeature); ``` ## Access the GeoJsonFeatures and their properties To access all the GeoJsonFeatures that have been added to the layer, you can call ` getFeatures()` on the `GeoJsonLayer` that you have created. This will return an iterable of `GeoJsonFeatures` that you can access using a for-each loop as shown below. ### Kotlin ```kotlin for (feature in layer.features) { // Do something to the feature } ``` ### Java ```java for (GeoJsonFeature feature : layer.getFeatures()) { // Do something to the feature } ``` Use the `hasProperty()` and `getProperty()` methods in conjunction with the `getFeatures()` method to check if each stored feature has a particular property and access it if it exists. ### Kotlin ```kotlin if (feature.hasProperty("Ocean")) { val oceanProperty = feature.getProperty("Ocean") } ``` ### Java ```java if (feature.hasProperty("Ocean")) { String oceanProperty = feature.getProperty("Ocean"); } ``` ## GeoJSON Geometry Click Events You can use `GeoJsonLayer.OnFeatureClickListener()` to listen for click events on the geometry features on the map. The following example logs the title of a feature when the user clicks the feature: ### Kotlin ```kotlin // Set a listener for geometry clicked events. layer.setOnFeatureClickListener { feature -> Log.i("GeoJsonClick", "Feature clicked: ${feature.getProperty("title")}") } ``` ### Java ```java // Set a listener for geometry clicked events. layer.setOnFeatureClickListener( new Layer.OnFeatureClickListener() { @Override public void onFeatureClick(Feature feature) { Log.i("GeoJsonClick", "Feature clicked: " + feature.getProperty("title")); } }); ``` ## Style the GeoJsonLayer and GeoJsonFeatures You can set default styles for a GeoJsonLayer, or style individual features in the layer. ### Default Styles In a GeoJsonLayer, you can set default styles for any points, linestrings and polygons that are added to the layer. Default styles are only applied if the feature does not have a style set for either of its geometries. Any changes you make on the default style will also be reflected in all features that are using the default style. The steps to apply a default style are as follows 1. Retrieve the relevant default style object, this can be one of a `GeoJsonPointStyle`, a `GeoJsonLineStringStyle` or a `GeoJsonPolygonStyle`. 2. Apply your desired options on the style. For example, the following code sample shows how to modify the default point style which will make points draggable with a title and snippet. ### Kotlin ```kotlin val pointStyle = layer.getDefaultPointStyle() pointStyle.setDraggable(true) pointStyle.setTitle("Hello, World!") pointStyle.setSnippet("I am a draggable marker") val lineStyle = layer.getDefaultLineStringStyle() val polygonStyle = layer.getDefaultPolygonStyle() ``` ### Java ```java GeoJsonPointStyle pointStyle = layer.getDefaultPointStyle(); pointStyle.setDraggable(true); pointStyle.setTitle("Hello, World!"); pointStyle.setSnippet("I am a draggable marker"); GeoJsonLineStringStyle lineStyle = layer.getDefaultLineStringStyle(); com.google.maps.android.data.geojson.GeoJsonPolygonStyle polygonStyle = layer.getDefaultPolygonStyle(); ``` ### Styles specific to a GeoJsonFeature Alternatively, you can style individual features in the layer. The steps to apply a style on a `GeoJsonFeature` are as follows. 1. Create the relevant style object, this can be either a `GeoJsonPointStyle`, `GeoJsonLineStringStyle` or `GeoJsonPolygonStyle`. 2. Apply your desired options on the style. 3. Pass the style object to the relevant method on the `GeoJsonFeature`, which will be either `setPointStyle()`, `setLineStringStyle()` or `setPolygonStyle()`. For example, this is how to customise the linestring style for a `GeoJsonFeature` so that its color is red. ### Kotlin ```kotlin // Create a new feature containing a linestring val lineStringArray: MutableList = ArrayList() lineStringArray.add(LatLng(0.0, 0.0)) lineStringArray.add(LatLng(50.0, 50.0)) val lineString = GeoJsonLineString(lineStringArray) val lineStringFeature = GeoJsonFeature(lineString, null, null, null) // Set the color of the linestring to red val lineStringStyle = GeoJsonLineStringStyle() lineStringStyle.color = Color.RED // Set the style of the feature lineStringFeature.lineStringStyle = lineStringStyle ``` ### Java ```java // Create a new feature containing a linestring List lineStringArray = new ArrayList(); lineStringArray.add(new LatLng(0, 0)); lineStringArray.add(new LatLng(50, 50)); GeoJsonLineString lineString = new GeoJsonLineString(lineStringArray); GeoJsonFeature lineStringFeature = new GeoJsonFeature(lineString, null, null, null); // Set the color of the linestring to red GeoJsonLineStringStyle lineStringStyle = new GeoJsonLineStringStyle(); lineStringStyle.setColor(Color.RED); // Set the style of the feature lineStringFeature.setLineStringStyle(lineStringStyle); ``` ## See the demo app For an example of importing a GeoJSON file from a URL and creating a layer with it, take a look at the `GeoJsonDemoActivity` in the demo app that ships with the utility library. The [setup guide](https://developers.google.com/maps/documentation/android-sdk/utility/setup.md.txt) shows you how to run the demo app.