thedelisle/atlas

Atlas, an offline reverse Geo-coding library written in Java.

Atlas  

Atlas, an offline reverse Geo-coding library written in Java, inspired by reverse-geocoder.

The index is a double SortedMap<Double, Set<City>> that keeps an index on both the latitudes and longitudes of the cities.

using Atlas

Clone this repository and add the library to your local Maven repos:

git clone https://github.com/bkiers/atlas.git
cd altas
mvn clean install

Add the following dependency to your project:

<dependency>
  <groupId>nl.big-o</groupId>
  <artifactId>atlas</artifactId>
  <version>0.1.0</version>
</dependency>

and use the library as follows:

// (lat, lng) somewhere in Venice
double lat = 45.436636;
double lng = 12.326413;

// Find a single city
City city = new Atlas().find(lat, lng);

System.out.println(city);
//    City{
//      geoNameId=3164603
//      name='Venice'
//      latitude=45.43713
//      longitude=12.33265
//      countryCode='IT'
//      timeZone='Europe/Rome'
//      admin1='Veneto'
//      admin2='Provincia di Venezia'
//    }

// Finds 3 cities around the (lat,lng) in a radius of 5 kilometers
List<City> cities = new Atlas()
    .withLimit(3)
    .withMaxDistance(5000)
    .findAll(lat, lng);

for (City c : cities) {
  System.out.println(c);
}
//      City{
//        geoNameId=3164603
//        name='Venice'
//        latitude=45.43713
//        longitude=12.33265
//        countryCode='IT'
//        timeZone='Europe/Rome'
//        admin1='Veneto'
//        admin2='Provincia di Venezia'
//      }
//      City{
//        geoNameId=3175265
//        name='Giudecca'
//        latitude=45.42477
//        longitude=12.32906
//        countryCode='IT'
//        timeZone='Europe/Rome'
//        admin1='Veneto'
//        admin2='Provincia di Venezia'
//      }
//      City{
//        geoNameId=3172456
//        name='Murano'
//        latitude=45.45857
//        longitude=12.35683
//        countryCode='IT'
//        timeZone='Europe/Rome'
//        admin1='Veneto'
//        admin2='Provincia di Venezia'
//      }

(re) creating the index

In order to recreate the index, download the cities1000.zip and unzip it in this project's ./data folder. Optionally also copy the files: admin1CodesASCII.txt and admin2Codes.txt to the ./data folder.

To create a new index containing all cities, simply run:

mvn -q exec:java
mvn package

which will create a JAR file, atlas-VERSION.jar, inside the ./target folder of approximately 5.6 Megabytes containing the entire index of all cities.

If you don't need all cities, you can create a smaller index. For example, if you want to create an index of the counties Spain and Portugal, do the following:

mvn -q exec:java -Dexec.args="ES,PT"
mvn package

credits

• data from GeoNames
• blazing fast (de)serialization using Kryo

license

MIT