location4j 🌎4️⃣♨️

location4j is a simple Java library designed for efficient and accurate geographical data lookups for countries, states, and cities. 🗺️

Unlike other libraries, it operates without relying on third-party APIs, making it both cost-effective and fast. 🏎️

Its built-in dataset provides quick lookups and no need for external HTTP calls. 📀

Setup 🚀

Get the latest version of the location4j library by adding it to your Maven pom.xml

<dependency>
    <groupId>com.tomaytotomato</groupId>
    <artifactId>location4j</artifactId>
    <version>1.0.5</version>
</dependency>

Gradle

implementation group: 'com.tomaytotomato', name: 'location4j', version: '1.0.5'

Quick Example 🏗

import com.tomaytotomato.SearchLocationService;

public class Main {

    public static void main(String[] args) {
        SearchLocationService searchLocationService = SearchLocationService.builder().build();

        // Find all locations named San Francisco
        List<Location> results = searchLocationService.search("san francisco");
        printResults(results);

        // Narrow search to the US
        results = searchLocationService.search("san francisco, us");
        printResults(results);

        // Narrow search further to California
        results = searchLocationService.search("san francisco, us california");
        printResults(results);
    }

    private static void printResults(List<Location> results) {
        System.out.println("Locations found: " + results.size());
        results.forEach(location -> {
            System.out.println("Country: " + location.getCountryName());
            System.out.println("State: " + location.getStateName());
            System.out.println("City: " + location.getCityName());
        });
    }
}

Features 🔬

Feature	Supported	Object	Example
Search (free text)	✅	Location	search("kyiv") -> "Kyiv, Ukraine, Europe, UA"
Find All Countries	✅	Country	findAllCountries() -> ["Belgium", "Canada", ...]
Find Country by Id	✅	Country	findCountryById(1) -> ["Afghanistan"]
Find Country by ISO2 code	✅	Country	findCountryByISO2Code("CA") -> ["Canada"]
Find Country by ISO3 code	✅	Country	findCountryByISO3Code("CAN") -> ["Canada"]
Find Country by Name	✅	Country	findCountryByName("Canada") -> ["Canada"]
Find Country by Localised name	✅	Country	findCountryByLocalisedName("Belgique") -> ["Belgium"]
Find Countries by State name	✅	Country	findAllCountriesByStateName("Texas") -> ["USA"]
Find States by State name	✅	State	findAllStatesByStateName("Texas") -> ["Texas", "USA"]
Find State by State Id	✅	State	findStateById(5) -> ["California", "USA"]
Find States by State code	✅	State	findAllStatesByStateCode("CA") -> ["California", "USA"]
Find City by City Id	✅	City	findCityById(10) -> ["Los Angeles", "California"]
Find City by latitude/longitude	✅	City	findClosestCityByLatLong(30.438, -84.280) -> ["Tallahassee", "Florida"]
Find Cities by City name	✅	City	findAllCitiesByCityName("San Francisco") -> ["San Francisco", "California"]

🟢 location4j can parse free text strings with or without punctuation or capitalisation e.g.

San Francisco, CA, USA

ca united states san francisco

US, San Francisco, california

🟢 Latitude/Longitude searches can use double, BigDecimal, or String inputs for both values; the types must match ( you can't mix a String latitude with a BigDecimal or double longitude) but the API will accept any of the three types.

🔴 location4j cannot find a location based on a small town, street, or zipcode/postcode.

More Examples 🧪

Lookup countries

For simple lookups the LocationService can act like a repository, allow the retrieval of countries, states and city information.

import com.tomaytotomato.LocationService;

public class LocationServiceExample {

    public static void main(String[] args) {
        LocationService locationService = LocationService.builder().build();

        // Get all countries
        List<Country> countries = locationService.findAllCountries();

        // Filter European countries
        List<Country> europeanCountries = countries.stream()
                .filter(country -> "Europe".equals(country.getRegion()))
                .toList();

        // Find Afghanistan by ID
        Country afghanistan = locationService.findCountryById(1);

        // Find all cities named San Francisco
        List<City> cities = locationService.findAllCities("San Francisco");

    }
}

Search locations

Search any text for a location, the SearchLocationService can handle formatted or unformatted text. It will try and find matches against a variety of keywords it has in its dataset.

import com.tomaytotomato.SearchLocationService;

public class SearchLocationServiceExample {

    public static void main(String[] args) {
        SearchLocationService searchLocationService = SearchLocationService.builder()
            .withTextNormaliser(new DefaultTextNormaliser())
            .build();

        // Search for Santa Clara
        List<Location> results = searchLocationService.search("Santa Clara");

        // Search for Santa Clara in the USA
        List<Location> resultsUnitedStates = searchLocationService.search("Santa Clara USA");

        // Search for Santa Clara in California (it works with ISO2 or ISO3) codes
        List<Location> resultsCalifornia = searchLocationService.search("Santa Clara US CA");
    }
}

Motivation 🌱

Parsing location data efficiently is crucial for many applications, yet it can be complex and time-consuming.

Third-party services like Google Location API can be costly, and using large language models can introduce significant latency.

location4j offers a practical solution with its own dataset, enabling fast and cost-effective geographical lookups to a city/town level (which is sufficient in most cases).

This allows applications to be built without another external dependency and the overheads that come with it.

I may add other functionality in the future if needed e.g. geolocation to nearest place, geofencing etc.

Credits 🙏

Country data sourced from dr5shn/countries-states-cities-database

License 📜

MIT License