com.mapbox.geojson.Feature Maven / Gradle / Ivy
package com.mapbox.geojson;
import androidx.annotation.Keep;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.TypeAdapter;
import com.google.gson.annotations.JsonAdapter;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
import com.google.gson.stream.JsonWriter;
import com.mapbox.geojson.gson.BoundingBoxTypeAdapter;
import com.mapbox.geojson.gson.GeoJsonAdapterFactory;
import java.io.IOException;
/**
* This defines a GeoJson Feature object which represents a spatially bound thing. Every Feature
* object is a GeoJson object no matter where it occurs in a GeoJson text. A Feature object will
* always have a "TYPE" member with the value "Feature".
*
* A Feature object has a member with the name "geometry". The value of the geometry member SHALL be
* either a Geometry object or, in the case that the Feature is unlocated, a JSON null value.
*
* A Feature object has a member with the name "properties". The value of the properties member is
* an object (any JSON object or a JSON null value).
*
* If a Feature has a commonly used identifier, that identifier SHOULD be included as a member of
* the Feature object through the {@link #id()} method, and the value of this member is either a
* JSON string or number.
*
* An example of a serialized feature is given below:
*
* {
* "TYPE": "Feature",
* "geometry": {
* "TYPE": "Point",
* "coordinates": [102.0, 0.5]
* },
* "properties": {
* "prop0": "value0"
* }
*
*
* @since 1.0.0
*/
@Keep
public final class Feature implements GeoJson {
private static final String TYPE = "Feature";
private final String type;
@JsonAdapter(BoundingBoxTypeAdapter.class)
private final BoundingBox bbox;
private final String id;
private final Geometry geometry;
private final JsonObject properties;
/**
* Create a new instance of this class by passing in a formatted valid JSON String. If you are
* creating a Feature object from scratch it is better to use one of the other provided static
* factory methods such as {@link #fromGeometry(Geometry)}.
*
* @param json a formatted valid JSON string defining a GeoJson Feature
* @return a new instance of this class defined by the values passed inside this static factory
* method
* @since 1.0.0
*/
public static Feature fromJson(@NonNull String json) {
GsonBuilder gson = new GsonBuilder();
gson.registerTypeAdapterFactory(GeoJsonAdapterFactory.create());
gson.registerTypeAdapterFactory(GeometryAdapterFactory.create());
Feature feature = gson.create().fromJson(json, Feature.class);
// Even thought properties are Nullable,
// Feature object will be created with properties set to an empty object,
// so that addProperties() would work
if (feature.properties() != null) {
return feature;
}
return new Feature(TYPE, feature.bbox(),
feature.id(), feature.geometry(), new JsonObject());
}
/**
* Create a new instance of this class by giving the feature a {@link Geometry}.
*
* @param geometry a single geometry which makes up this feature object
* @return a new instance of this class defined by the values passed inside this static factory
* method
* @since 1.0.0
*/
public static Feature fromGeometry(@Nullable Geometry geometry) {
return new Feature(TYPE, null, null, geometry, new JsonObject());
}
/**
* Create a new instance of this class by giving the feature a {@link Geometry}. You can also pass
* in a double array defining a bounding box.
*
* @param geometry a single geometry which makes up this feature object
* @param bbox optionally include a bbox definition as a double array
* @return a new instance of this class defined by the values passed inside this static factory
* method
* @since 1.0.0
*/
public static Feature fromGeometry(@Nullable Geometry geometry, @Nullable BoundingBox bbox) {
return new Feature(TYPE, bbox, null, geometry, new JsonObject());
}
/**
* Create a new instance of this class by giving the feature a {@link Geometry} and optionally a
* set of properties.
*
* @param geometry a single geometry which makes up this feature object
* @param properties a {@link JsonObject} containing the feature properties
* @return a new instance of this class defined by the values passed inside this static factory
* method
* @since 1.0.0
*/
public static Feature fromGeometry(@Nullable Geometry geometry, @Nullable JsonObject properties) {
return new Feature(TYPE, null, null, geometry,
properties == null ? new JsonObject() : properties);
}
/**
* Create a new instance of this class by giving the feature a {@link Geometry}, optionally a
* set of properties, and optionally pass in a bbox.
*
* @param geometry a single geometry which makes up this feature object
* @param bbox optionally include a bbox definition as a double array
* @param properties a {@link JsonObject} containing the feature properties
* @return a new instance of this class defined by the values passed inside this static factory
* method
* @since 1.0.0
*/
public static Feature fromGeometry(@Nullable Geometry geometry, @Nullable JsonObject properties,
@Nullable BoundingBox bbox) {
return new Feature(TYPE, bbox, null, geometry,
properties == null ? new JsonObject() : properties);
}
/**
* Create a new instance of this class by giving the feature a {@link Geometry}, optionally a
* set of properties, and a String which represents the objects id.
*
* @param geometry a single geometry which makes up this feature object
* @param properties a {@link JsonObject} containing the feature properties
* @param id common identifier of this feature
* @return {@link Feature}
* @since 1.0.0
*/
public static Feature fromGeometry(@Nullable Geometry geometry, @Nullable JsonObject properties,
@Nullable String id) {
return new Feature(TYPE, null, id, geometry,
properties == null ? new JsonObject() : properties);
}
/**
* Create a new instance of this class by giving the feature a {@link Geometry}, optionally a
* set of properties, and a String which represents the objects id.
*
* @param geometry a single geometry which makes up this feature object
* @param properties a {@link JsonObject} containing the feature properties
* @param bbox optionally include a bbox definition as a double array
* @param id common identifier of this feature
* @return {@link Feature}
* @since 1.0.0
*/
public static Feature fromGeometry(@Nullable Geometry geometry, @NonNull JsonObject properties,
@Nullable String id, @Nullable BoundingBox bbox) {
return new Feature(TYPE, bbox, id, geometry,
properties == null ? new JsonObject() : properties);
}
Feature(String type, @Nullable BoundingBox bbox, @Nullable String id,
@Nullable Geometry geometry, @Nullable JsonObject properties) {
if (type == null) {
throw new NullPointerException("Null type");
}
this.type = type;
this.bbox = bbox;
this.id = id;
this.geometry = geometry;
this.properties = properties;
}
/**
* This describes the TYPE of GeoJson geometry this object is, thus this will always return
* {@link Feature}.
*
* @return a String which describes the TYPE of geometry, for this object it will always return
* {@code Feature}
* @since 1.0.0
*/
@NonNull
@Override
public String type() {
return type;
}
/**
* A Feature Collection might have a member named {@code bbox} to include information on the
* coordinate range for it's {@link Feature}s. The value of the bbox member MUST be a list of
* size 2*n where n is the number of dimensions represented in the contained feature geometries,
* with all axes of the most southwesterly point followed by all axes of the more northeasterly
* point. The axes order of a bbox follows the axes order of geometries.
*
* @return a list of double coordinate values describing a bounding box
* @since 3.0.0
*/
@Nullable
@Override
public BoundingBox bbox() {
return bbox;
}
/**
* A feature may have a commonly used identifier which is either a unique String or number.
*
* @return a String containing this features unique identification or null if one wasn't given
* during creation.
* @since 1.0.0
*/
@Nullable
public String id() {
return id;
}
/**
* The geometry which makes up this feature. A Geometry object represents points, curves, and
* surfaces in coordinate space. One of the seven geometries provided inside this library can be
* passed in through one of the static factory methods.
*
* @return a single defined {@link Geometry} which makes this feature spatially aware
* @since 1.0.0
*/
@Nullable
public Geometry geometry() {
return geometry;
}
/**
* This contains the JSON object which holds the feature properties. The value of the properties
* member is a {@link JsonObject} and might be empty if no properties are provided.
*
* @return a {@link JsonObject} which holds this features current properties
* @since 1.0.0
*/
@Nullable
public JsonObject properties() {
return properties;
}
/**
* This takes the currently defined values found inside this instance and converts it to a GeoJson
* string.
*
* @return a JSON string which represents this Feature
* @since 1.0.0
*/
@Override
public String toJson() {
Gson gson = new GsonBuilder()
.registerTypeAdapterFactory(GeoJsonAdapterFactory.create())
.registerTypeAdapterFactory(GeometryAdapterFactory.create())
.create();
// Empty properties -> should not appear in json string
Feature feature = this;
if (properties().size() == 0) {
feature = new Feature(TYPE, bbox(), id(), geometry(), null);
}
return gson.toJson(feature);
}
/**
* Gson TYPE adapter for parsing Gson to this class.
*
* @param gson the built {@link Gson} object
* @return the TYPE adapter for this class
* @since 3.0.0
*/
public static TypeAdapter typeAdapter(Gson gson) {
return new Feature.GsonTypeAdapter(gson);
}
/**
* Convenience method to add a String member.
*
* @param key name of the member
* @param value the String value associated with the member
* @since 1.0.0
*/
public void addStringProperty(String key, String value) {
properties().addProperty(key, value);
}
/**
* Convenience method to add a Number member.
*
* @param key name of the member
* @param value the Number value associated with the member
* @since 1.0.0
*/
public void addNumberProperty(String key, Number value) {
properties().addProperty(key, value);
}
/**
* Convenience method to add a Boolean member.
*
* @param key name of the member
* @param value the Boolean value associated with the member
* @since 1.0.0
*/
public void addBooleanProperty(String key, Boolean value) {
properties().addProperty(key, value);
}
/**
* Convenience method to add a Character member.
*
* @param key name of the member
* @param value the Character value associated with the member
* @since 1.0.0
*/
public void addCharacterProperty(String key, Character value) {
properties().addProperty(key, value);
}
/**
* Convenience method to add a JsonElement member.
*
* @param key name of the member
* @param value the JsonElement value associated with the member
* @since 1.0.0
*/
public void addProperty(String key, JsonElement value) {
properties().add(key, value);
}
/**
* Convenience method to get a String member.
*
* @param key name of the member
* @return the value of the member, null if it doesn't exist
* @since 1.0.0
*/
public String getStringProperty(String key) {
JsonElement propertyKey = properties().get(key);
return propertyKey == null ? null : propertyKey.getAsString();
}
/**
* Convenience method to get a Number member.
*
* @param key name of the member
* @return the value of the member, null if it doesn't exist
* @since 1.0.0
*/
public Number getNumberProperty(String key) {
JsonElement propertyKey = properties().get(key);
return propertyKey == null ? null : propertyKey.getAsNumber();
}
/**
* Convenience method to get a Boolean member.
*
* @param key name of the member
* @return the value of the member, null if it doesn't exist
* @since 1.0.0
*/
public Boolean getBooleanProperty(String key) {
JsonElement propertyKey = properties().get(key);
return propertyKey == null ? null : propertyKey.getAsBoolean();
}
/**
* Convenience method to get a Character member.
*
* @param key name of the member
* @return the value of the member, null if it doesn't exist
* @since 1.0.0
*/
public Character getCharacterProperty(String key) {
JsonElement propertyKey = properties().get(key);
return propertyKey == null ? null : propertyKey.getAsCharacter();
}
/**
* Convenience method to get a JsonElement member.
*
* @param key name of the member
* @return the value of the member, null if it doesn't exist
* @since 1.0.0
*/
public JsonElement getProperty(String key) {
return properties().get(key);
}
/**
* Removes the property from the object properties.
*
* @param key name of the member
* @return Removed {@code property} from the key string passed in through the parameter.
* @since 1.0.0
*/
public JsonElement removeProperty(String key) {
return properties().remove(key);
}
/**
* Convenience method to check if a member with the specified name is present in this object.
*
* @param key name of the member
* @return true if there is the member has the specified name, false otherwise.
* @since 1.0.0
*/
public boolean hasProperty(String key) {
return properties().has(key);
}
/**
* Convenience method to check for a member by name as well as non-null value.
*
* @param key name of the member
* @return true if member is present with non-null value, false otherwise.
* @since 1.3.0
*/
public boolean hasNonNullValueForProperty(String key) {
return hasProperty(key) && !getProperty(key).isJsonNull();
}
@Override
public String toString() {
return "Feature{"
+ "type=" + type + ", "
+ "bbox=" + bbox + ", "
+ "id=" + id + ", "
+ "geometry=" + geometry + ", "
+ "properties=" + properties
+ "}";
}
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (obj instanceof Feature) {
Feature that = (Feature) obj;
return (this.type.equals(that.type()))
&& ((this.bbox == null) ? (that.bbox() == null) : this.bbox.equals(that.bbox()))
&& ((this.id == null) ? (that.id() == null) : this.id.equals(that.id()))
&& ((this.geometry == null)
? (that.geometry() == null) : this.geometry.equals(that.geometry()))
&& ((this.properties == null)
? (that.properties() == null) : this.properties.equals(that.properties()));
}
return false;
}
@Override
public int hashCode() {
int hashCode = 1;
hashCode *= 1000003;
hashCode ^= type.hashCode();
hashCode *= 1000003;
hashCode ^= (bbox == null) ? 0 : bbox.hashCode();
hashCode *= 1000003;
hashCode ^= (id == null) ? 0 : id.hashCode();
hashCode *= 1000003;
hashCode ^= (geometry == null) ? 0 : geometry.hashCode();
hashCode *= 1000003;
hashCode ^= (properties == null) ? 0 : properties.hashCode();
return hashCode;
}
/**
* TypeAdapter to serialize/deserialize Feature objects.
*
* @since 4.6.0
*/
static final class GsonTypeAdapter extends TypeAdapter {
private volatile TypeAdapter stringTypeAdapter;
private volatile TypeAdapter boundingBoxTypeAdapter;
private volatile TypeAdapter geometryTypeAdapter;
private volatile TypeAdapter jsonObjectTypeAdapter;
private final Gson gson;
GsonTypeAdapter(Gson gson) {
this.gson = gson;
}
@Override
public void write(JsonWriter jsonWriter, Feature object) throws IOException {
if (object == null) {
jsonWriter.nullValue();
return;
}
jsonWriter.beginObject();
jsonWriter.name("type");
if (object.type() == null) {
jsonWriter.nullValue();
} else {
TypeAdapter stringTypeAdapter = this.stringTypeAdapter;
if (stringTypeAdapter == null) {
stringTypeAdapter = gson.getAdapter(String.class);
this.stringTypeAdapter = stringTypeAdapter;
}
stringTypeAdapter.write(jsonWriter, object.type());
}
jsonWriter.name("bbox");
if (object.bbox() == null) {
jsonWriter.nullValue();
} else {
TypeAdapter boundingBoxTypeAdapter = this.boundingBoxTypeAdapter;
if (boundingBoxTypeAdapter == null) {
boundingBoxTypeAdapter = gson.getAdapter(BoundingBox.class);
this.boundingBoxTypeAdapter = boundingBoxTypeAdapter;
}
boundingBoxTypeAdapter.write(jsonWriter, object.bbox());
}
jsonWriter.name("id");
if (object.id() == null) {
jsonWriter.nullValue();
} else {
TypeAdapter stringTypeAdapter = this.stringTypeAdapter;
if (stringTypeAdapter == null) {
stringTypeAdapter = gson.getAdapter(String.class);
this.stringTypeAdapter = stringTypeAdapter;
}
stringTypeAdapter.write(jsonWriter, object.id());
}
jsonWriter.name("geometry");
if (object.geometry() == null) {
jsonWriter.nullValue();
} else {
TypeAdapter geometryTypeAdapter = this.geometryTypeAdapter;
if (geometryTypeAdapter == null) {
geometryTypeAdapter = gson.getAdapter(Geometry.class);
this.geometryTypeAdapter = geometryTypeAdapter;
}
geometryTypeAdapter.write(jsonWriter, object.geometry());
}
jsonWriter.name("properties");
if (object.properties() == null) {
jsonWriter.nullValue();
} else {
TypeAdapter jsonObjectTypeAdapter = this.jsonObjectTypeAdapter;
if (jsonObjectTypeAdapter == null) {
jsonObjectTypeAdapter = gson.getAdapter(JsonObject.class);
this.jsonObjectTypeAdapter = jsonObjectTypeAdapter;
}
jsonObjectTypeAdapter.write(jsonWriter, object.properties());
}
jsonWriter.endObject();
}
@Override
public Feature read(JsonReader jsonReader) throws IOException {
if (jsonReader.peek() == JsonToken.NULL) {
jsonReader.nextNull();
return null;
}
jsonReader.beginObject();
String type = null;
BoundingBox bbox = null;
String id = null;
Geometry geometry = null;
JsonObject properties = null;
while (jsonReader.hasNext()) {
String name = jsonReader.nextName();
if (jsonReader.peek() == JsonToken.NULL) {
jsonReader.nextNull();
continue;
}
switch (name) {
case "type":
TypeAdapter strTypeAdapter = this.stringTypeAdapter;
if (strTypeAdapter == null) {
strTypeAdapter = gson.getAdapter(String.class);
this.stringTypeAdapter = strTypeAdapter;
}
type = strTypeAdapter.read(jsonReader);
break;
case "bbox":
TypeAdapter boundingBoxTypeAdapter = this.boundingBoxTypeAdapter;
if (boundingBoxTypeAdapter == null) {
boundingBoxTypeAdapter = gson.getAdapter(BoundingBox.class);
this.boundingBoxTypeAdapter = boundingBoxTypeAdapter;
}
bbox = boundingBoxTypeAdapter.read(jsonReader);
break;
case "id":
strTypeAdapter = this.stringTypeAdapter;
if (strTypeAdapter == null) {
strTypeAdapter = gson.getAdapter(String.class);
this.stringTypeAdapter = strTypeAdapter;
}
id = strTypeAdapter.read(jsonReader);
break;
case "geometry":
TypeAdapter geometryTypeAdapter = this.geometryTypeAdapter;
if (geometryTypeAdapter == null) {
geometryTypeAdapter = gson.getAdapter(Geometry.class);
this.geometryTypeAdapter = geometryTypeAdapter;
}
geometry = geometryTypeAdapter.read(jsonReader);
break;
case "properties":
TypeAdapter jsonObjectTypeAdapter = this.jsonObjectTypeAdapter;
if (jsonObjectTypeAdapter == null) {
jsonObjectTypeAdapter = gson.getAdapter(JsonObject.class);
this.jsonObjectTypeAdapter = jsonObjectTypeAdapter;
}
properties = jsonObjectTypeAdapter.read(jsonReader);
break;
default:
jsonReader.skipValue();
}
}
jsonReader.endObject();
return new Feature(type, bbox, id, geometry, properties);
}
}
}