gbfs-loader-java

Manage loading of GBFS feeds and updating them based on their ttl and last_updated fields.

The loader uses the generated GBFS Java model (http://github.com/entur/gbfs-java-model) to deserialize the files.

Usage

GbfsLoader directly

You may use the GbfsLoader directly. You will need to create one instance per GBFS feed (system). The loader will use the discovery file to fetch all other available files.

The GbfsLoader class has two factory methods, one for GBFS v2 and one for GBFS v3:

    GbfsV2Loader loader = GbfsLoader.gbfsV2Loader(
            "http://example.com/gbfs.json",
            Map.of(),
            "en",
            null, // optional RequestAuthenticator
            null // optional timeout override
    )

    // Same as above except language code is dropped
    GbfsV3Loader v3loader = GbfsLoader.gbfsV3Loader(
            "http://example.com/gbfs.json",
            Map.of(),
            null, // optional RequestAuthenticator
            null // optional timeout override
    )


    // If the update fetched any files
    if (loader.update()) {

        // Get the data for a specific fiile
        GbfsStationStatus stationStatus = loader.getData(GbfsStationStatus.class);
    }

Use subscriptions

For convenience, a set of classes is provided to encapsulate the loader into a subscription for each feed, and with a delivery class that contains all files for each feed.

The main entrypoint, GbfsSubscriptionManager, has two subscribe methods, one for GBFS v2 and one for GBFS v3. I.e., when you subscribe to a GBFS feed, you must know in advance if it is version 2.x or version 3.x.

    GbfsSubscriptionManager subscriptions = new GbfsSubscriptionManager();

    // Subscribe to as many feeds as you want
    GbfsSubscriptionOptions options = new GbfsSubscriptionOptions();
    options.setDiscoveryURI(new URI("file:src/test/resources/gbfs/lillestrombysykkel/gbfs.json"));
    options.setLanguageCode("nb");

    String subscriber = subscriptions.subscribeV2(options, delivery -> {
        // Consume an update on the subscription
        Assertions.assertEquals(6, delivery.getStationStatus().getData().getStations().size());
    });

    // Use your own scheduler to update the subscriptions
    subscriptions.update();

Authentication

The GbfsLoader constructor, as well as the GbfsSubscriptionOptions have an optional RequestAuthenticator parameter. Use this with GBFS feeds that require authentication.

The following implementations are provided in this library: Oauth2ClientCredentialsGrantRequestAuthenticator, BearerTokenRequestAuthenticator and HttpHeadersRequestAuthenticator. You can also implement the RequestAuthenticator interface to provide use custom authentication schemes.

Maven central

This project is available in the central maven repository. See https://search.maven.org/search?q=g:org.entur.gbfs