Realtime Configuration Guide

While OneBusAway can work with just static schedule data, all the most interesting features require real-time transit information.

GTFS-realtime

We support GTFS-realtime out of the box, including support for trip updates, vehicle positions, and alerts. To add support, create a GtfsRealtimeSource bean in your data-sources.xml file. Then specify URLs for the three different types of GTFS-realtime data as properties of the bean. Here is a full example:

<bean class="org.onebusaway.transit_data_federation.impl.realtime.gtfs_realtime.GtfsRealtimeSource">
  <property name="tripUpdatesUrl" value="http://url/to/gtfs-realtime/trip-updates" />
  <property name="vehiclePositionsUrl" value="http://url/to/gtfs-realtime/vehicle-positions" />
  <property name="alertsUrl" value="http://url/to/gtfs-realtime/alerts" />
  <!-- Optionally set the refresh interval - how often we query the URLs, in seconds (default=30) -->
  <property name="refreshInterval" value="30"/>
  <!-- Optionally configure the agency id we use to match incoming data -->
  <property name="agencyId" value="SomeAgencyId" />
  <property name="agencyIds>
    <list>
      <value>SomeAgencyIdA</value>
      <value>SomeAgencyIdB</value>
    </list>
  </property>
</bean>

You can additionally specify a refreshInterval that controls how often we query the URLs, in seconds. If you are deploying a multi-agency instance of OneBusAway, you may also need to specify the agencyId or agencyIds of the transit agency to associate the incoming GTFS-realtime data with. This allows you to define multiple incoming GTFS-realtime data-sources from different agencies in the same system.

You must provide both a TripUpdates feed and a VehiclePositions feed in order for OneBusAway to report vehicle positions. Without a TripUpdates feed OneBusAway will discard the vehicle positions.

SIRI VM

We support SIRI out of the box, including support for vehicle monitoring (VM) and situation exchange (SX). To add support, create a SiriController bean in your data-sources.xml file. Then specify SIRI endpoint requests indicating your SIRI data-source. Here is a full example:

<!-- The "name" parameter controls which URL the SIRI client listens for pub-sub data.  See "clientUrl" below. -->
<bean name="/siri.action" class="org.onebusaway.transit_data_federation_webapp.siri.SiriController">
  <!-- Specify the SIRI endpoint -->
  <property name="endpoint" value="Url=http://host/siri-endpoing.xml,ModuleType=VEHICLE_MONITORING" />
  <!-- Or you can specify a series of endpoints -->
  <property name="endpoints">
    <list>
      <value>...</value>
      <value>...</value>
    </list>
  </property>
  <!-- Control the URL your SIRI client publically broadcasts to endpoints for pub-sub data exchange -->
  <property name="clientUrl" value="http://localhost:8080/onebusaway-transit-data-federation-webapp/remoting/siri.action" />
  <!-- Want to see what's going on behind the scenes with SIRI XML messages? -->
  <property name="logRawXmlType" value="CONTROL"/>
</bean>

Orbital/ACS/Xerox OrbCAD

A number of agencies have Orbital/ACS/Xerox OrbCAD AVL systems. Some agencies have configured the data-export option of these systems to spit out a CSV file of vehicle locations and schedule deviations for all the vehicles in their fleet, which is then shared through a webserver. OneBusAway supports data of this form. To add support, create a OrbcadRecordHttpSource bean in your data-sources.xml file. Then specify the URL for your real-time data file. Here is a full example:

<bean class="org.onebusaway.transit_data_federation.impl.realtime.orbcad.OrbcadRecordHttpSource">
  <property name="url" value="http://host/busdata.txt" />
  <!-- Optionally configure the agency id we use to match incoming data -->
  <property name="agencyIds">
    <list>
      <value>SomeAgencyId</value>
    </list>
  </property>
</bean>

Custom Implementation

Interested in adapting your own real-time system to OneBusAway? The best option is to create an adapter between your system and an existing specification like GTFS-realtime or SIRI and then use OneBusAway’s native support for those formats.

However, if that’s not going to cut it, you can create your own custom real-time data-source plugin to OneBusAway. This might be a good solution if you need direct access to OneBusAway data-structures and service interfaces to process your real-time data.

Creating a custom implementation typically involves the following steps:

  • Create a Java class that implements your real-time data-source.
  • Add your class to the OneBusAway application server class path.
  • Create an instance of your class in your data-source.xml file.
  • Have your implementation periodically notify OneBusAway of new real-time data using the VehicleLocationListener interface.

Here is a quick example to get you started:

public MyRealTimeSource {

  private VehicleLocationListener _listener

  @Autowired
  public void setVehicleLocationListener(VehicleLocationListener listener) {
    _listener = listener;
  }

  @PostConstruct
  public void start() {
    // Span a thread that periodically poll your data-source, or some other method of receiving data
  }

  @PreDestroy {
  public void stop() {
    // Shut-down any threads you started
  }

  public void processRealTimeData(...) {
    VehicleLocationRecord record = createRercordFromRealTimeData(...);
    _listener.handleVehicleLocationRecord(record);
  }
}