README.md

Java GTFS-realtime Language Bindings

Provides Java classes generated from the GTFS-realtime Protocol Buffer specification. These classes will allow you to parse a binary Protocol Buffer GTFS-realtime data feed into Java objects.

Add the Dependency

To use the gtfs-realtime-bindings classes in your own project, you need to add an appropriate dependency. We publish our module to the Maven Central Repository so that it can be easily referenced by Java build tools like Maven, Ivy, and Gradle.

For Maven, add the following to your pom.xml dependencies section:

<dependency>
  <groupId>io.mobilitydata.transit</groupId>
  <artifactId>gtfs-realtime-bindings</artifactId>
  <version>0.0.7</version>
</dependency>

For Gradle, add the following to your build.gradle dependecies section:

compile group: 'io.mobilitydata.transit', name: 'gtfs-realtime-bindings', version: '0.0.7'

Make sure the Maven central repository is referenced by your project.

Example Code

The following code snippet demonstrates downloading a GTFS-realtime data feed from a particular URL, parsing it as a FeedMessage (the root type of the GTFS-realtime schema), and iterating over the results.

import java.net.URL;

import com.google.transit.realtime.GtfsRealtime.FeedEntity;
import com.google.transit.realtime.GtfsRealtime.FeedMessage;

public class GtfsRealtimeExample {
  public static void main(String[] args) throws Exception {
    URL url = new URL("URL OF YOUR GTFS-REALTIME SOURCE GOES HERE");
    FeedMessage feed = FeedMessage.parseFrom(url.openStream());
    for (FeedEntity entity : feed.getEntityList()) {
      if (entity.hasTripUpdate()) {
        System.out.println(entity.getTripUpdate());
      }
    }
  }
}

For more details on the naming conventions for the Java classes generated from the gtfs-realtime.proto, check out the Java Generated Code section of the Protocol Buffers developer site.