A reverse geocoder that converts latitude and longitude coordinates to country information such as names, ISO codes and locales.
ReverseGeocoder geocoder = new ReverseGeocoder();
geocoder.getCountry(51.507222, -0.1275).ifPresent(country -> {
System.out.println(country.iso()); // GB
System.out.println(country.iso3()); // GBR
System.out.println(country.isoNumeric()); // 826
System.out.println(country.name()); // United Kingdom
System.out.println(country.area()); // 244820.0
System.out.println(country.population()); // 62348447
System.out.println(country.continent()); // EU
List<Locale> locales = country.locales();
System.out.println(locales.get(0)); // en_GB
System.out.println(locales.get(1)); // cy_GB
System.out.println(locales.get(2)); // gd
});Country information and boundary data comes from GeoNames.
97.92% when ran against the GeoNames data set for cities with a population > 15000.
~3 μs average to look up city from the GeoNames data set on a 13" MacBook Pro (i5-5257U) using a single thread. The retained heap size for ReverseGeocoder is ~7.5 MB.
Country bounding boxes are loaded into R-Trees using the Sort-Tile-Recursive algorithm. Determining if a point lies within a polygon is performed using the PNPOLY algorithm.
Build jar:
./gradlew assemble
Download new Geonames data:
./gradlew updateCountryInfo updateShapes
Run benchmarks:
./gradlew jmh
Generate new baseline test data:
./gradlew generateBaseline
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