diff --git a/enabler/pom.xml b/enabler/pom.xml
index ef9f22d1..8b9db106 100644
--- a/enabler/pom.xml
+++ b/enabler/pom.xml
@@ -23,6 +23,13 @@
 			<version>18.0</version>
 		</dependency>
 
+		<!-- javax.annotation.* -->
+		<dependency>
+			<groupId>com.google.code.findbugs</groupId>
+			<artifactId>jsr305</artifactId>
+			<version>3.0.0</version>
+		</dependency>
+
 		<dependency>
 			<groupId>org.json</groupId>
 			<artifactId>json</artifactId>
diff --git a/enabler/src/de/schildbach/pte/AbstractEfaProvider.java b/enabler/src/de/schildbach/pte/AbstractEfaProvider.java
index 453a7193..75d040db 100644
--- a/enabler/src/de/schildbach/pte/AbstractEfaProvider.java
+++ b/enabler/src/de/schildbach/pte/AbstractEfaProvider.java
@@ -17,6 +17,7 @@
 
 package de.schildbach.pte;
 
+import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 
 import java.io.IOException;
@@ -40,6 +41,8 @@ import java.util.concurrent.atomic.AtomicReference;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import javax.annotation.Nullable;
+
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
@@ -93,14 +96,14 @@ public abstract class AbstractEfaProvider extends AbstractNetworkProvider
 	private final String coordEndpoint;
 
 	private String language = "de";
-	private String additionalQueryParameter = null;
+	private @Nullable String additionalQueryParameter = null;
 	private boolean useRealtime = true;
 	private boolean needsSpEncId = false;
 	private boolean includeRegionId = true;
 	private boolean useProxFootSearch = true;
 	private Charset requestUrlEncoding = Charsets.ISO_8859_1;
-	private String httpReferer = null;
-	private String httpRefererTrip = null;
+	private @Nullable String httpReferer = null;
+	private @Nullable String httpRefererTrip = null;
 	private boolean httpPost = false;
 	private boolean useRouteIndexAsTripId = true;
 	private boolean useLineRestriction = true;
@@ -999,8 +1002,8 @@ public abstract class AbstractEfaProvider extends AbstractNetworkProvider
 	private static final Pattern P_LINE_S_DB = Pattern.compile("(S\\d+) \\((?:DB Regio AG)\\)");
 	private static final Pattern P_LINE_NUMBER = Pattern.compile("\\d+");
 
-	protected Line parseLine(final String id, final String mot, String symbol, final String name, final String longName, final String trainType,
-			final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if (mot == null)
 		{
@@ -1370,7 +1373,7 @@ public abstract class AbstractEfaProvider extends AbstractNetworkProvider
 				return new Line(id, Product.BUS, "SEV" + trainNumStr);
 			if ("Bus replacement".equals(trainName)) // GB
 				return new Line(id, Product.BUS, "BR");
-			if ("BR".equals(trainType) && trainName.startsWith("Bus")) // GB
+			if ("BR".equals(trainType) && trainName != null && trainName.startsWith("Bus")) // GB
 				return new Line(id, Product.BUS, "BR" + trainNum);
 
 			if ("GB".equals(trainType)) // Gondelbahn
@@ -1440,13 +1443,13 @@ public abstract class AbstractEfaProvider extends AbstractNetworkProvider
 				+ "' trainType='" + trainType + "' trainNum='" + trainNum + "' trainName='" + trainName + "'");
 	}
 
-	public QueryDeparturesResult queryDepartures(final String stationId, final Date time, final int maxDepartures, final boolean equivs)
+	public QueryDeparturesResult queryDepartures(final String stationId, final @Nullable Date time, final int maxDepartures, final boolean equivs)
 			throws IOException
 	{
 		return xsltDepartureMonitorRequest(stationId, time, maxDepartures, equivs);
 	}
 
-	protected StringBuilder xsltDepartureMonitorRequestParameters(final String stationId, final Date time, final int maxDepartures,
+	protected StringBuilder xsltDepartureMonitorRequestParameters(final String stationId, final @Nullable Date time, final int maxDepartures,
 			final boolean equivs)
 	{
 		final StringBuilder parameters = new StringBuilder();
@@ -1482,8 +1485,8 @@ public abstract class AbstractEfaProvider extends AbstractNetworkProvider
 		uri.append("&itdTime=").append(ParserUtils.urlEncode(String.format(Locale.ENGLISH, "%02d%02d", hour, minute)));
 	}
 
-	private QueryDeparturesResult xsltDepartureMonitorRequest(final String stationId, final Date time, final int maxDepartures, final boolean equivs)
-			throws IOException
+	private QueryDeparturesResult xsltDepartureMonitorRequest(final String stationId, final @Nullable Date time, final int maxDepartures,
+			final boolean equivs) throws IOException
 	{
 		final StringBuilder parameters = xsltDepartureMonitorRequestParameters(stationId, time, maxDepartures, equivs);
 
@@ -1562,8 +1565,9 @@ public abstract class AbstractEfaProvider extends AbstractNetworkProvider
 						assignedStationDepartures = new StationDepartures(new Location(LocationType.STATION, assignedStopId),
 								new LinkedList<Departure>(), new LinkedList<LineDestination>());
 
-					if (!assignedStationDepartures.lines.contains(line))
-						assignedStationDepartures.lines.add(line);
+					final List<LineDestination> assignedStationDeparturesLines = checkNotNull(assignedStationDepartures.lines);
+					if (!assignedStationDeparturesLines.contains(line))
+						assignedStationDeparturesLines.add(line);
 				}
 				XmlPullUtil.skipExit(pp, "itdServingLines");
 			}
@@ -1646,8 +1650,8 @@ public abstract class AbstractEfaProvider extends AbstractNetworkProvider
 		}
 	}
 
-	protected QueryDeparturesResult queryDeparturesMobile(final String stationId, final Date time, final int maxDepartures, final boolean equivs)
-			throws IOException
+	protected QueryDeparturesResult queryDeparturesMobile(final String stationId, final @Nullable Date time, final int maxDepartures,
+			final boolean equivs) throws IOException
 	{
 		final StringBuilder parameters = xsltDepartureMonitorRequestParameters(stationId, time, maxDepartures, equivs);
 
@@ -1850,7 +1854,7 @@ public abstract class AbstractEfaProvider extends AbstractNetworkProvider
 	private StationDepartures findStationDepartures(final List<StationDepartures> stationDepartures, final String id)
 	{
 		for (final StationDepartures stationDeparture : stationDepartures)
-			if (stationDeparture.location.id.equals(id))
+			if (id.equals(stationDeparture.location.id))
 				return stationDeparture;
 
 		return null;
@@ -1994,8 +1998,9 @@ public abstract class AbstractEfaProvider extends AbstractNetworkProvider
 		return (double) value / 1000000;
 	}
 
-	protected String xsltTripRequestParameters(final Location from, final Location via, final Location to, final Date time, final boolean dep,
-			final Collection<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility, final Set<Option> options)
+	protected String xsltTripRequestParameters(final Location from, final @Nullable Location via, final Location to, final Date time,
+			final boolean dep, final @Nullable Collection<Product> products, final @Nullable WalkSpeed walkSpeed,
+			final @Nullable Accessibility accessibility, final @Nullable Set<Option> options)
 	{
 		final StringBuilder uri = new StringBuilder();
 		appendCommonRequestParams(uri, "XML");
@@ -2099,8 +2104,9 @@ public abstract class AbstractEfaProvider extends AbstractNetworkProvider
 			uri.append("&coordListOutputFormat=STRING");
 	}
 
-	public QueryTripsResult queryTrips(final Location from, final Location via, final Location to, final Date date, final boolean dep,
-			final Set<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility, final Set<Option> options) throws IOException
+	public QueryTripsResult queryTrips(final Location from, final @Nullable Location via, final Location to, final Date date, final boolean dep,
+			final @Nullable Set<Product> products, final @Nullable WalkSpeed walkSpeed, final @Nullable Accessibility accessibility,
+			final @Nullable Set<Option> options) throws IOException
 	{
 
 		final String parameters = xsltTripRequestParameters(from, via, to, date, dep, products, walkSpeed, accessibility, options);
@@ -2137,9 +2143,9 @@ public abstract class AbstractEfaProvider extends AbstractNetworkProvider
 		}
 	}
 
-	protected QueryTripsResult queryTripsMobile(final Location from, final Location via, final Location to, final Date date, final boolean dep,
-			final Collection<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility, final Set<Option> options)
-			throws IOException
+	protected QueryTripsResult queryTripsMobile(final Location from, final @Nullable Location via, final Location to, final Date date,
+			final boolean dep, final @Nullable Collection<Product> products, final @Nullable WalkSpeed walkSpeed,
+			final @Nullable Accessibility accessibility, final @Nullable Set<Option> options) throws IOException
 	{
 
 		final String parameters = xsltTripRequestParameters(from, via, to, date, dep, products, walkSpeed, accessibility, options);
@@ -2645,11 +2651,11 @@ public abstract class AbstractEfaProvider extends AbstractNetworkProvider
 								final int size = intermediateStops.size();
 								if (size >= 2)
 								{
-									if (!intermediateStops.get(size - 1).location.id.equals(arrivalLocation.id))
+									if (!intermediateStops.get(size - 1).location.equals(arrivalLocation))
 										throw new IllegalStateException();
 									intermediateStops.remove(size - 1);
 
-									if (!intermediateStops.get(0).location.id.equals(departureLocation.id))
+									if (!intermediateStops.get(0).location.equals(departureLocation))
 										throw new IllegalStateException();
 									intermediateStops.remove(0);
 								}
@@ -2786,8 +2792,8 @@ public abstract class AbstractEfaProvider extends AbstractNetworkProvider
 		return new QueryTripsResult(header, uri, from, via, to, new Context(commandLink((String) context, requestId)), trips);
 	}
 
-	private QueryTripsResult queryTripsMobile(final String uri, final Location from, final Location via, final Location to, final InputStream is)
-			throws XmlPullParserException, IOException
+	private QueryTripsResult queryTripsMobile(final String uri, final Location from, final @Nullable Location via, final Location to,
+			final InputStream is) throws XmlPullParserException, IOException
 	{
 		// System.out.println(uri);
 
diff --git a/enabler/src/de/schildbach/pte/AbstractHafasProvider.java b/enabler/src/de/schildbach/pte/AbstractHafasProvider.java
index 15679ba7..65b58b92 100644
--- a/enabler/src/de/schildbach/pte/AbstractHafasProvider.java
+++ b/enabler/src/de/schildbach/pte/AbstractHafasProvider.java
@@ -42,6 +42,8 @@ import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import javax.annotation.Nullable;
+
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
@@ -53,6 +55,7 @@ import com.google.common.base.Charsets;
 
 import de.schildbach.pte.dto.Departure;
 import de.schildbach.pte.dto.Line;
+import de.schildbach.pte.dto.Line.Attr;
 import de.schildbach.pte.dto.Location;
 import de.schildbach.pte.dto.LocationType;
 import de.schildbach.pte.dto.NearbyLocationsResult;
@@ -88,14 +91,14 @@ public abstract class AbstractHafasProvider extends AbstractNetworkProvider
 	protected final String getStopEndpoint;
 	protected final String queryEndpoint;
 	private final int numProductBits;
-	private String accessId;
-	private String clientType;
+	private @Nullable String accessId = null;
+	private @Nullable String clientType = null;
 	private Charset jsonGetStopsEncoding;
 	private boolean jsonGetStopsUseWeight = true;
 	private Charset jsonNearbyLocationsEncoding;
 	private boolean dominantPlanStopTime = false;
 	private boolean useIso8601 = false;
-	private String extXmlEndpoint = null;
+	private @Nullable String extXmlEndpoint = null;
 	private boolean stationBoardHasStationTable = true;
 	private boolean stationBoardHasLocation = false;
 	private boolean stationBoardCanDoEquivs = true;
@@ -443,7 +446,7 @@ public abstract class AbstractHafasProvider extends AbstractNetworkProvider
 		}
 	}
 
-	public QueryDeparturesResult queryDepartures(final String stationId, final Date time, final int maxDepartures, final boolean equivs)
+	public QueryDeparturesResult queryDepartures(final String stationId, final @Nullable Date time, final int maxDepartures, final boolean equivs)
 			throws IOException
 	{
 		final StringBuilder uri = new StringBuilder(stationBoardEndpoint);
@@ -452,8 +455,8 @@ public abstract class AbstractHafasProvider extends AbstractNetworkProvider
 		return xmlStationBoard(uri.toString(), stationId);
 	}
 
-	protected void appendXmlStationBoardParameters(final StringBuilder uri, final Date time, final String stationId, final int maxDepartures,
-			final boolean equivs, final String styleSheet)
+	protected void appendXmlStationBoardParameters(final StringBuilder uri, final @Nullable Date time, final String stationId,
+			final int maxDepartures, final boolean equivs, final @Nullable String styleSheet)
 	{
 		uri.append("?productsFilter=").append(allProductsString());
 		uri.append("&boardType=dep");
@@ -652,8 +655,9 @@ public abstract class AbstractHafasProvider extends AbstractNetworkProvider
 						if (product == null)
 							throw new IllegalArgumentException();
 						// could check for type consistency here
-						if (prodLine.attrs != null)
-							line = newLine(product, prodLine.label, null, prodLine.attrs.toArray(new Line.Attr[0]));
+						final Set<Attr> attrs = prodLine.attrs;
+						if (attrs != null)
+							line = newLine(product, prodLine.label, null, attrs.toArray(new Line.Attr[0]));
 						else
 							line = newLine(product, prodLine.label, null);
 					}
@@ -747,8 +751,9 @@ public abstract class AbstractHafasProvider extends AbstractNetworkProvider
 	{
 	}
 
-	public QueryTripsResult queryTrips(final Location from, final Location via, final Location to, final Date date, final boolean dep,
-			final Set<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility, final Set<Option> options) throws IOException
+	public QueryTripsResult queryTrips(final Location from, final @Nullable Location via, final Location to, final Date date, final boolean dep,
+			final @Nullable Set<Product> products, final @Nullable WalkSpeed walkSpeed, final @Nullable Accessibility accessibility,
+			final @Nullable Set<Option> options) throws IOException
 	{
 		return queryTripsBinary(from, via, to, date, dep, products, walkSpeed, accessibility, options);
 	}
@@ -758,9 +763,9 @@ public abstract class AbstractHafasProvider extends AbstractNetworkProvider
 		return queryMoreTripsBinary(context, later);
 	}
 
-	protected final QueryTripsResult queryTripsXml(Location from, Location via, Location to, final Date date, final boolean dep,
-			final Collection<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility, final Set<Option> options)
-			throws IOException
+	protected final QueryTripsResult queryTripsXml(Location from, @Nullable Location via, Location to, final Date date, final boolean dep,
+			final @Nullable Collection<Product> products, final @Nullable WalkSpeed walkSpeed, final @Nullable Accessibility accessibility,
+			final @Nullable Set<Option> options) throws IOException
 	{
 		final ResultHeader header = new ResultHeader(SERVER_PRODUCT);
 
@@ -859,7 +864,7 @@ public abstract class AbstractHafasProvider extends AbstractNetworkProvider
 	}
 
 	private QueryTripsResult queryTripsXml(final Context previousContext, final boolean later, final CharSequence conReq, final Location from,
-			final Location via, final Location to) throws IOException
+			final @Nullable Location via, final Location to) throws IOException
 	{
 		final String request = wrapReqC(conReq, null);
 
@@ -1187,7 +1192,7 @@ public abstract class AbstractHafasProvider extends AbstractNetworkProvider
 					// remove last intermediate
 					if (intermediateStops != null)
 						if (!intermediateStops.isEmpty())
-							if (!intermediateStops.get(intermediateStops.size() - 1).location.id.equals(sectionArrivalLocation.id))
+							if (!intermediateStops.get(intermediateStops.size() - 1).location.equals(sectionArrivalLocation))
 								intermediateStops.remove(intermediateStops.size() - 1);
 
 					XmlPullUtil.skipExit(pp, "ConSection");
@@ -1353,8 +1358,9 @@ public abstract class AbstractHafasProvider extends AbstractNetworkProvider
 		throw new IllegalArgumentException(location.type.toString());
 	}
 
-	protected void appendQueryTripsBinaryParameters(final StringBuilder uri, final Location from, final Location via, final Location to,
-			final Date date, final boolean dep, final Collection<Product> products, final Accessibility accessibility, final Set<Option> options)
+	protected void appendQueryTripsBinaryParameters(final StringBuilder uri, final Location from, final @Nullable Location via, final Location to,
+			final Date date, final boolean dep, final @Nullable Collection<Product> products, final @Nullable Accessibility accessibility,
+			final @Nullable Set<Option> options)
 	{
 		uri.append("?start=Suchen");
 
@@ -1428,9 +1434,9 @@ public abstract class AbstractHafasProvider extends AbstractNetworkProvider
 
 	private final static int QUERY_TRIPS_BINARY_BUFFER_SIZE = 384 * 1024;
 
-	protected final QueryTripsResult queryTripsBinary(Location from, Location via, Location to, final Date date, final boolean dep,
-			final Collection<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility, final Set<Option> options)
-			throws IOException
+	protected final QueryTripsResult queryTripsBinary(Location from, @Nullable Location via, Location to, final Date date, final boolean dep,
+			final @Nullable Collection<Product> products, final @Nullable WalkSpeed walkSpeed, final @Nullable Accessibility accessibility,
+			final @Nullable Set<Option> options) throws IOException
 	{
 		final ResultHeader header = new ResultHeader(SERVER_PRODUCT);
 
@@ -1504,7 +1510,7 @@ public abstract class AbstractHafasProvider extends AbstractNetworkProvider
 		}
 	}
 
-	private QueryTripsResult queryTripsBinary(final String uri, final Location from, final Location via, final Location to,
+	private QueryTripsResult queryTripsBinary(final String uri, final Location from, final @Nullable Location via, final Location to,
 			final int expectedBufferSize) throws IOException
 	{
 		/*
diff --git a/enabler/src/de/schildbach/pte/AbstractNavitiaProvider.java b/enabler/src/de/schildbach/pte/AbstractNavitiaProvider.java
index 5f726434..f71c137f 100644
--- a/enabler/src/de/schildbach/pte/AbstractNavitiaProvider.java
+++ b/enabler/src/de/schildbach/pte/AbstractNavitiaProvider.java
@@ -17,6 +17,8 @@
 
 package de.schildbach.pte;
 
+import static com.google.common.base.Preconditions.checkNotNull;
+
 import java.io.IOException;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
@@ -30,6 +32,8 @@ import java.util.Map;
 import java.util.Set;
 import java.util.WeakHashMap;
 
+import javax.annotation.Nullable;
+
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
@@ -96,8 +100,8 @@ public abstract class AbstractNavitiaProvider extends AbstractNetworkProvider
 
 	private static class Context implements QueryTripsContext
 	{
-		private Location from;
-		private Location to;
+		private final Location from;
+		private final Location to;
 		private final String prevQueryUri;
 		private final String nextQueryUri;
 
@@ -831,7 +835,7 @@ public abstract class AbstractNavitiaProvider extends AbstractNetworkProvider
 		}
 	}
 
-	public QueryDeparturesResult queryDepartures(final String stationId, final Date time, final int maxDepartures, final boolean equivs)
+	public QueryDeparturesResult queryDepartures(final String stationId, final @Nullable Date time, final int maxDepartures, final boolean equivs)
 			throws IOException
 	{
 		final ResultHeader resultHeader = new ResultHeader(SERVER_PRODUCT, SERVER_VERSION, 0, null);
@@ -885,7 +889,7 @@ public abstract class AbstractNavitiaProvider extends AbstractNetworkProvider
 					final List<LineDestination> lineDestinations = getStationLines(location.id);
 
 					for (LineDestination lineDestination : lineDestinations)
-						stationDepartures.lines.add(lineDestination);
+						checkNotNull(stationDepartures.lines).add(lineDestination);
 				}
 
 				// Build departure date.
@@ -981,8 +985,9 @@ public abstract class AbstractNavitiaProvider extends AbstractNetworkProvider
 		}
 	}
 
-	public QueryTripsResult queryTrips(final Location from, final Location via, final Location to, final Date date, final boolean dep,
-			final Set<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility, final Set<Option> options) throws IOException
+	public QueryTripsResult queryTrips(final Location from, final @Nullable Location via, final Location to, final Date date, final boolean dep,
+			final @Nullable Set<Product> products, final @Nullable WalkSpeed walkSpeed, final @Nullable Accessibility accessibility,
+			final @Nullable Set<Option> options) throws IOException
 	{
 		final ResultHeader resultHeader = new ResultHeader(SERVER_PRODUCT, SERVER_VERSION, 0, null);
 
@@ -990,32 +995,34 @@ public abstract class AbstractNavitiaProvider extends AbstractNetworkProvider
 		{
 			if (from != null && from.isIdentified() && to != null && to.isIdentified())
 			{
-				final String fromString = printLocation(from);
-				final String toString = printLocation(to);
-				final String dateString = printDate(date);
-				final String dateTimeRep = dep ? "departure" : "arrival";
+				final StringBuilder queryUri = new StringBuilder(tripUri()).append("journeys");
+				queryUri.append("?from=").append(ParserUtils.urlEncode(printLocation(from)));
+				queryUri.append("&to=").append(ParserUtils.urlEncode(printLocation(to)));
+				queryUri.append("&datetime=").append(printDate(date));
+				queryUri.append("&datetime_represents=").append(dep ? "departure" : "arrival");
+				queryUri.append("&count=").append(this.numTripsRequested);
+				queryUri.append("&depth=0");
 
 				// Set walking speed.
-				final double walkingSpeed;
-				switch (walkSpeed)
+				if (walkSpeed != null)
 				{
-					case SLOW:
-						walkingSpeed = 1.12 * 0.8;
-						break;
-					case NORMAL:
-						walkingSpeed = 1.12;
-						break;
-					case FAST:
-						walkingSpeed = 1.12 * 1.2;
-						break;
-					default:
-						walkingSpeed = 1.12;
-						break;
-				}
+					final double walkingSpeed;
+					switch (walkSpeed)
+					{
+						case SLOW:
+							walkingSpeed = 1.12 * 0.8;
+							break;
+						case FAST:
+							walkingSpeed = 1.12 * 1.2;
+							break;
+						case NORMAL:
+						default:
+							walkingSpeed = 1.12;
+							break;
+					}
 
-				final StringBuilder queryUri = new StringBuilder(tripUri() + "journeys?" + "from=" + ParserUtils.urlEncode(fromString) + "&to="
-						+ ParserUtils.urlEncode(toString) + "&datetime=" + dateString + "&datetime_represents=" + dateTimeRep + "&count="
-						+ this.numTripsRequested + "&walking_speed=" + walkingSpeed + "&depth=0");
+					queryUri.append("&walking_speed=").append(walkingSpeed);
+				}
 
 				if (options != null && options.contains(Option.BIKE))
 				{
@@ -1024,7 +1031,7 @@ public abstract class AbstractNavitiaProvider extends AbstractNetworkProvider
 				}
 
 				// Set forbidden commercial modes.
-				if (!products.equals(Product.ALL))
+				if (products != null && !products.equals(Product.ALL))
 				{
 					if (!products.contains(Product.SUBURBAN_TRAIN))
 					{
diff --git a/enabler/src/de/schildbach/pte/AbstractNetworkProvider.java b/enabler/src/de/schildbach/pte/AbstractNetworkProvider.java
index dabda7d3..7753d8b3 100644
--- a/enabler/src/de/schildbach/pte/AbstractNetworkProvider.java
+++ b/enabler/src/de/schildbach/pte/AbstractNetworkProvider.java
@@ -25,6 +25,8 @@ import java.util.TimeZone;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.Strings;
 
 import de.schildbach.pte.dto.Point;
@@ -41,8 +43,8 @@ public abstract class AbstractNetworkProvider implements NetworkProvider
 
 	protected TimeZone timeZone = TimeZone.getTimeZone("CET");
 	protected int numTripsRequested = 6;
-	private Map<String, Style> styles = null;
-	protected String sessionCookieName = null;
+	private @Nullable Map<String, Style> styles = null;
+	protected @Nullable String sessionCookieName = null;
 
 	public final boolean hasCapabilities(final Capability... capabilities)
 	{
@@ -82,8 +84,9 @@ public abstract class AbstractNetworkProvider implements NetworkProvider
 
 	private static final char STYLES_SEP = '|';
 
-	public Style lineStyle(final String network, final Product product, final String label)
+	public Style lineStyle(final @Nullable String network, final @Nullable Product product, final @Nullable String label)
 	{
+		final Map<String, Style> styles = this.styles;
 		if (styles != null && product != null)
 		{
 			if (network != null)
@@ -99,7 +102,7 @@ public abstract class AbstractNetworkProvider implements NetworkProvider
 					return productStyle;
 
 				// check for night bus, as that's a common special case
-				if (product == Product.BUS && label.startsWith("N"))
+				if (product == Product.BUS && label != null && label.startsWith("N"))
 				{
 					final Style nightStyle = styles.get(network + STYLES_SEP + "BN");
 					if (nightStyle != null)
@@ -119,7 +122,7 @@ public abstract class AbstractNetworkProvider implements NetworkProvider
 				return productStyle;
 
 			// check for night bus, as that's a common special case
-			if (product == Product.BUS && label.startsWith("N"))
+			if (product == Product.BUS && label != null && label.startsWith("N"))
 			{
 				final Style nightStyle = styles.get("BN");
 				if (nightStyle != null)
diff --git a/enabler/src/de/schildbach/pte/AbstractTsiProvider.java b/enabler/src/de/schildbach/pte/AbstractTsiProvider.java
index 78c89dd0..d6f55807 100644
--- a/enabler/src/de/schildbach/pte/AbstractTsiProvider.java
+++ b/enabler/src/de/schildbach/pte/AbstractTsiProvider.java
@@ -34,6 +34,8 @@ import java.util.Map;
 import java.util.Set;
 import java.util.TimeZone;
 
+import javax.annotation.Nullable;
+
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
@@ -164,7 +166,7 @@ public abstract class AbstractTsiProvider extends AbstractNetworkProvider
 		return (double) value / 1000000;
 	}
 
-	private final String apiKey;
+	private final @Nullable String apiKey;
 	private final String stopFinderEndpoint;
 	private final String tripEndpoint;
 
@@ -604,7 +606,7 @@ public abstract class AbstractTsiProvider extends AbstractNetworkProvider
 		return new Location(locType, id, Point.fromDouble(lat, lon), place, name);
 	}
 
-	public QueryDeparturesResult queryDepartures(final String stationId, final Date time, final int maxDepartures, final boolean equivs)
+	public QueryDeparturesResult queryDepartures(final String stationId, final @Nullable Date time, final int maxDepartures, final boolean equivs)
 			throws IOException
 	{
 		throw new UnsupportedOperationException();
@@ -632,8 +634,9 @@ public abstract class AbstractTsiProvider extends AbstractNetworkProvider
 		return jsonCoordRequest(location.lat, location.lon, maxDistance, maxLocations);
 	}
 
-	public QueryTripsResult queryTrips(final Location from, final Location via, final Location to, final Date date, final boolean dep,
-			final Set<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility, final Set<Option> options) throws IOException
+	public QueryTripsResult queryTrips(final Location from, final @Nullable Location via, final Location to, final Date date, final boolean dep,
+			final @Nullable Set<Product> products, final @Nullable WalkSpeed walkSpeed, final @Nullable Accessibility accessibility,
+			final @Nullable Set<Option> options) throws IOException
 	{
 		final List<Location> possibleFroms, possibleTos, possibleVias;
 
diff --git a/enabler/src/de/schildbach/pte/AvvProvider.java b/enabler/src/de/schildbach/pte/AvvProvider.java
index c8225ca5..1f83af7a 100644
--- a/enabler/src/de/schildbach/pte/AvvProvider.java
+++ b/enabler/src/de/schildbach/pte/AvvProvider.java
@@ -20,6 +20,8 @@ package de.schildbach.pte;
 import java.util.HashMap;
 import java.util.Map;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Line;
 import de.schildbach.pte.dto.Product;
 import de.schildbach.pte.dto.Style;
@@ -46,8 +48,8 @@ public class AvvProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("0".equals(mot))
 		{
diff --git a/enabler/src/de/schildbach/pte/BayernProvider.java b/enabler/src/de/schildbach/pte/BayernProvider.java
index 091eadd2..b0de9de1 100644
--- a/enabler/src/de/schildbach/pte/BayernProvider.java
+++ b/enabler/src/de/schildbach/pte/BayernProvider.java
@@ -22,6 +22,8 @@ import java.util.Date;
 import java.util.EnumSet;
 import java.util.Set;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.Charsets;
 
 import de.schildbach.pte.dto.Line;
@@ -63,8 +65,8 @@ public class BayernProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("0".equals(mot))
 		{
@@ -117,7 +119,7 @@ public class BayernProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	public QueryDeparturesResult queryDepartures(final String stationId, final Date time, final int maxDepartures, final boolean equivs)
+	public QueryDeparturesResult queryDepartures(final String stationId, final @Nullable Date time, final int maxDepartures, final boolean equivs)
 			throws IOException
 	{
 		return queryDeparturesMobile(stationId, time, maxDepartures, equivs);
@@ -130,8 +132,9 @@ public class BayernProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	public QueryTripsResult queryTrips(final Location from, final Location via, final Location to, final Date date, final boolean dep,
-			final Set<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility, final Set<Option> options) throws IOException
+	public QueryTripsResult queryTrips(final Location from, final @Nullable Location via, final Location to, final Date date, final boolean dep,
+			final @Nullable Set<Product> products, final @Nullable WalkSpeed walkSpeed, final @Nullable Accessibility accessibility,
+			final @Nullable Set<Option> options) throws IOException
 	{
 		return queryTripsMobile(from, via, to, date, dep, products, walkSpeed, accessibility, options);
 	}
diff --git a/enabler/src/de/schildbach/pte/EireannProvider.java b/enabler/src/de/schildbach/pte/EireannProvider.java
index d1b2734f..dd1d7e04 100644
--- a/enabler/src/de/schildbach/pte/EireannProvider.java
+++ b/enabler/src/de/schildbach/pte/EireannProvider.java
@@ -23,6 +23,8 @@ import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Line;
 import de.schildbach.pte.dto.Location;
 import de.schildbach.pte.dto.Product;
@@ -89,8 +91,9 @@ public class EireannProvider extends AbstractHafasProvider
 	}
 
 	@Override
-	public QueryTripsResult queryTrips(final Location from, final Location via, final Location to, final Date date, final boolean dep,
-			final Set<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility, final Set<Option> options) throws IOException
+	public QueryTripsResult queryTrips(final Location from, final @Nullable Location via, final Location to, final Date date, final boolean dep,
+			final @Nullable Set<Product> products, final @Nullable WalkSpeed walkSpeed, final @Nullable Accessibility accessibility,
+			final @Nullable Set<Option> options) throws IOException
 	{
 		return queryTripsXml(from, via, to, date, dep, products, walkSpeed, accessibility, options);
 	}
diff --git a/enabler/src/de/schildbach/pte/InvgProvider.java b/enabler/src/de/schildbach/pte/InvgProvider.java
index 2a39122e..78bf4444 100644
--- a/enabler/src/de/schildbach/pte/InvgProvider.java
+++ b/enabler/src/de/schildbach/pte/InvgProvider.java
@@ -31,6 +31,8 @@ import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.Charsets;
 
 import de.schildbach.pte.dto.Departure;
@@ -176,7 +178,7 @@ public class InvgProvider extends AbstractHafasProvider
 	, Pattern.DOTALL);
 
 	@Override
-	public QueryDeparturesResult queryDepartures(final String stationId, final Date time, final int maxDepartures, final boolean equivs)
+	public QueryDeparturesResult queryDepartures(final String stationId, final @Nullable Date time, final int maxDepartures, final boolean equivs)
 			throws IOException
 	{
 		final ResultHeader header = new ResultHeader(SERVER_PRODUCT);
@@ -305,8 +307,9 @@ public class InvgProvider extends AbstractHafasProvider
 	}
 
 	@Override
-	public QueryTripsResult queryTrips(final Location from, final Location via, final Location to, final Date date, final boolean dep,
-			final Set<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility, final Set<Option> options) throws IOException
+	public QueryTripsResult queryTrips(final Location from, final @Nullable Location via, final Location to, final Date date, final boolean dep,
+			final @Nullable Set<Product> products, final @Nullable WalkSpeed walkSpeed, final @Nullable Accessibility accessibility,
+			final @Nullable Set<Option> options) throws IOException
 	{
 		return queryTripsXml(from, via, to, date, dep, products, walkSpeed, accessibility, options);
 	}
diff --git a/enabler/src/de/schildbach/pte/KvvProvider.java b/enabler/src/de/schildbach/pte/KvvProvider.java
index 5c2dd4c8..6399bd57 100644
--- a/enabler/src/de/schildbach/pte/KvvProvider.java
+++ b/enabler/src/de/schildbach/pte/KvvProvider.java
@@ -22,6 +22,8 @@ import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Line;
 import de.schildbach.pte.dto.Style;
 import de.schildbach.pte.dto.Style.Shape;
@@ -55,8 +57,8 @@ public class KvvProvider extends AbstractEfaProvider
 	private static final Pattern P_LINE = Pattern.compile("(.*?)\\s+\\([\\w/]+\\)", Pattern.CASE_INSENSITIVE);
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if (name != null)
 		{
diff --git a/enabler/src/de/schildbach/pte/MetProvider.java b/enabler/src/de/schildbach/pte/MetProvider.java
index 30522778..c9942b1e 100644
--- a/enabler/src/de/schildbach/pte/MetProvider.java
+++ b/enabler/src/de/schildbach/pte/MetProvider.java
@@ -20,6 +20,8 @@ package de.schildbach.pte;
 import java.util.HashMap;
 import java.util.Map;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.Strings;
 
 import de.schildbach.pte.dto.Line;
@@ -53,8 +55,8 @@ public class MetProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("0".equals(mot))
 		{
diff --git a/enabler/src/de/schildbach/pte/MvvProvider.java b/enabler/src/de/schildbach/pte/MvvProvider.java
index f8a2362f..2a2fd858 100644
--- a/enabler/src/de/schildbach/pte/MvvProvider.java
+++ b/enabler/src/de/schildbach/pte/MvvProvider.java
@@ -22,6 +22,8 @@ import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Line;
 import de.schildbach.pte.dto.Point;
 import de.schildbach.pte.dto.Position;
@@ -56,8 +58,8 @@ public class MvvProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("0".equals(mot))
 		{
diff --git a/enabler/src/de/schildbach/pte/NetworkProvider.java b/enabler/src/de/schildbach/pte/NetworkProvider.java
index fac9be31..9a6f822a 100644
--- a/enabler/src/de/schildbach/pte/NetworkProvider.java
+++ b/enabler/src/de/schildbach/pte/NetworkProvider.java
@@ -22,6 +22,8 @@ import java.util.Date;
 import java.util.EnumSet;
 import java.util.Set;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Location;
 import de.schildbach.pte.dto.LocationType;
 import de.schildbach.pte.dto.NearbyLocationsResult;
@@ -72,12 +74,13 @@ public interface NetworkProvider
 	boolean hasCapabilities(final Capability... capabilities);
 
 	/**
-	 * Find locations near to given location. At least one of lat/lon pair or station id must be present.
+	 * Find locations near to given location. At least one of lat/lon pair or station id must be present in that
+	 * location.
 	 * 
 	 * @param types
 	 *            types of locations to find
 	 * @param location
-	 *            location to determine nearby stations (optional)
+	 *            location to determine nearby stations
 	 * @param maxDistance
 	 *            maximum distance in meters, or {@code 0}
 	 * @param maxLocations
@@ -93,7 +96,7 @@ public interface NetworkProvider
 	 * @param stationId
 	 *            id of the station
 	 * @param time
-	 *            desired time for departing, optional
+	 *            desired time for departing, or {@code null} for the provider default
 	 * @param maxDepartures
 	 *            maximum number of departures to get or {@code 0}
 	 * @param equivs
@@ -101,7 +104,7 @@ public interface NetworkProvider
 	 * @return result object containing the departures
 	 * @throws IOException
 	 */
-	QueryDeparturesResult queryDepartures(String stationId, Date time, int maxDepartures, boolean equivs) throws IOException;
+	QueryDeparturesResult queryDepartures(String stationId, @Nullable Date time, int maxDepartures, boolean equivs) throws IOException;
 
 	/**
 	 * Meant for auto-completion of location names, like in an {@link android.widget.AutoCompleteTextView}
@@ -134,18 +137,18 @@ public interface NetworkProvider
 	 * @param dep
 	 *            date is departure date? {@code true} for departure, {@code false} for arrival
 	 * @param products
-	 *            products to take into account
+	 *            products to take into account, or {@code null} for the provider default
 	 * @param walkSpeed
-	 *            how fast can you walk?
+	 *            walking ability, or {@code null} for the provider default
 	 * @param accessibility
-	 *            how accessible do you need the route to be?
+	 *            route accessibility, or {@code null} for the provider default
 	 * @param options
-	 *            additional options
+	 *            additional options, or {@code null} for the provider default
 	 * @return result object that can contain alternatives to clear up ambiguousnesses, or contains possible trips
 	 * @throws IOException
 	 */
-	QueryTripsResult queryTrips(Location from, Location via, Location to, Date date, boolean dep, Set<Product> products, WalkSpeed walkSpeed,
-			Accessibility accessibility, Set<Option> options) throws IOException;
+	QueryTripsResult queryTrips(Location from, @Nullable Location via, Location to, Date date, boolean dep, @Nullable Set<Product> products,
+			@Nullable WalkSpeed walkSpeed, @Nullable Accessibility accessibility, @Nullable Set<Option> options) throws IOException;
 
 	/**
 	 * Query more trips (e.g. earlier or later)
@@ -163,14 +166,14 @@ public interface NetworkProvider
 	 * Get style of line
 	 * 
 	 * @param network
-	 *            network to disambiguate line
+	 *            network to disambiguate line, may be {@code null}
 	 * @param product
-	 *            line product to get style of
+	 *            line product to get style of, may be {@code null}
 	 * @param label
-	 *            line label to get style of, or null
+	 *            line label to get style of, may be {@code null}
 	 * @return object containing background, foreground and optional border colors
 	 */
-	Style lineStyle(String network, Product product, String label);
+	Style lineStyle(@Nullable String network, @Nullable Product product, @Nullable String label);
 
 	/**
 	 * Gets the primary covered area of the network
diff --git a/enabler/src/de/schildbach/pte/NriProvider.java b/enabler/src/de/schildbach/pte/NriProvider.java
index 330c93e5..5cf5cc40 100644
--- a/enabler/src/de/schildbach/pte/NriProvider.java
+++ b/enabler/src/de/schildbach/pte/NriProvider.java
@@ -21,6 +21,8 @@ import java.io.IOException;
 import java.util.Date;
 import java.util.Set;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.Charsets;
 
 import de.schildbach.pte.dto.Location;
@@ -130,8 +132,9 @@ public class NriProvider extends AbstractHafasProvider
 	}
 
 	@Override
-	public QueryTripsResult queryTrips(final Location from, final Location via, final Location to, final Date date, final boolean dep,
-			final Set<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility, final Set<Option> options) throws IOException
+	public QueryTripsResult queryTrips(final Location from, final @Nullable Location via, final Location to, final Date date, final boolean dep,
+			final @Nullable Set<Product> products, final @Nullable WalkSpeed walkSpeed, final @Nullable Accessibility accessibility,
+			final @Nullable Set<Option> options) throws IOException
 	{
 		return queryTripsXml(from, via, to, date, dep, products, walkSpeed, accessibility, options);
 	}
diff --git a/enabler/src/de/schildbach/pte/NvbwProvider.java b/enabler/src/de/schildbach/pte/NvbwProvider.java
index 2de70cad..beb0eaa4 100644
--- a/enabler/src/de/schildbach/pte/NvbwProvider.java
+++ b/enabler/src/de/schildbach/pte/NvbwProvider.java
@@ -23,6 +23,8 @@ import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Line;
 import de.schildbach.pte.dto.Location;
 import de.schildbach.pte.dto.Product;
@@ -58,8 +60,8 @@ public class NvbwProvider extends AbstractEfaProvider
 	private static final Pattern P_LINE_S_AVG_VBK = Pattern.compile("(S\\d+) \\((?:AVG|VBK)\\)");
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("0".equals(mot))
 		{
@@ -104,8 +106,9 @@ public class NvbwProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	public QueryTripsResult queryTrips(final Location from, final Location via, final Location to, final Date date, final boolean dep,
-			final Set<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility, final Set<Option> options) throws IOException
+	public QueryTripsResult queryTrips(final Location from, final @Nullable Location via, final Location to, final Date date, final boolean dep,
+			final @Nullable Set<Product> products, final @Nullable WalkSpeed walkSpeed, final @Nullable Accessibility accessibility,
+			final @Nullable Set<Option> options) throws IOException
 	{
 		return queryTripsMobile(from, via, to, date, dep, products, walkSpeed, accessibility, options);
 	}
diff --git a/enabler/src/de/schildbach/pte/SeptaProvider.java b/enabler/src/de/schildbach/pte/SeptaProvider.java
index 0b609832..37b817b0 100644
--- a/enabler/src/de/schildbach/pte/SeptaProvider.java
+++ b/enabler/src/de/schildbach/pte/SeptaProvider.java
@@ -30,6 +30,8 @@ import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Departure;
 import de.schildbach.pte.dto.Line;
 import de.schildbach.pte.dto.Location;
@@ -162,7 +164,7 @@ public class SeptaProvider extends AbstractHafasProvider
 	, Pattern.DOTALL);
 
 	@Override
-	public QueryDeparturesResult queryDepartures(final String stationId, final Date time, final int maxDepartures, final boolean equivs)
+	public QueryDeparturesResult queryDepartures(final String stationId, final @Nullable Date time, final int maxDepartures, final boolean equivs)
 			throws IOException
 	{
 		final ResultHeader header = new ResultHeader(SERVER_PRODUCT);
@@ -282,8 +284,9 @@ public class SeptaProvider extends AbstractHafasProvider
 	}
 
 	@Override
-	public QueryTripsResult queryTrips(final Location from, final Location via, final Location to, final Date date, final boolean dep,
-			final Set<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility, final Set<Option> options) throws IOException
+	public QueryTripsResult queryTrips(final Location from, final @Nullable Location via, final Location to, final Date date, final boolean dep,
+			final @Nullable Set<Product> products, final @Nullable WalkSpeed walkSpeed, final @Nullable Accessibility accessibility,
+			final @Nullable Set<Option> options) throws IOException
 	{
 		return queryTripsXml(from, via, to, date, dep, products, walkSpeed, accessibility, options);
 	}
diff --git a/enabler/src/de/schildbach/pte/SfProvider.java b/enabler/src/de/schildbach/pte/SfProvider.java
index d2d0b698..2e47978e 100644
--- a/enabler/src/de/schildbach/pte/SfProvider.java
+++ b/enabler/src/de/schildbach/pte/SfProvider.java
@@ -20,6 +20,8 @@ package de.schildbach.pte;
 import java.util.HashMap;
 import java.util.Map;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Line;
 import de.schildbach.pte.dto.Product;
 import de.schildbach.pte.dto.Style;
@@ -58,8 +60,8 @@ public class SfProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("0".equals(mot))
 		{
diff --git a/enabler/src/de/schildbach/pte/StvProvider.java b/enabler/src/de/schildbach/pte/StvProvider.java
index cbeaf012..9029f2ec 100644
--- a/enabler/src/de/schildbach/pte/StvProvider.java
+++ b/enabler/src/de/schildbach/pte/StvProvider.java
@@ -17,6 +17,8 @@
 
 package de.schildbach.pte;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Line;
 import de.schildbach.pte.dto.Product;
 
@@ -41,8 +43,8 @@ public class StvProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("0".equals(mot))
 		{
diff --git a/enabler/src/de/schildbach/pte/SydneyProvider.java b/enabler/src/de/schildbach/pte/SydneyProvider.java
index f7425579..ef20269b 100644
--- a/enabler/src/de/schildbach/pte/SydneyProvider.java
+++ b/enabler/src/de/schildbach/pte/SydneyProvider.java
@@ -20,6 +20,8 @@ package de.schildbach.pte;
 import java.util.HashMap;
 import java.util.Map;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Line;
 import de.schildbach.pte.dto.Product;
 import de.schildbach.pte.dto.Style;
@@ -58,8 +60,8 @@ public class SydneyProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("1".equals(mot))
 		{
diff --git a/enabler/src/de/schildbach/pte/TfiProvider.java b/enabler/src/de/schildbach/pte/TfiProvider.java
index 68cfbdeb..1c367f27 100644
--- a/enabler/src/de/schildbach/pte/TfiProvider.java
+++ b/enabler/src/de/schildbach/pte/TfiProvider.java
@@ -19,6 +19,8 @@ package de.schildbach.pte;
 
 import java.util.Set;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Line;
 import de.schildbach.pte.dto.Product;
 
@@ -50,8 +52,8 @@ public class TfiProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("0".equals(mot))
 		{
diff --git a/enabler/src/de/schildbach/pte/TlemProvider.java b/enabler/src/de/schildbach/pte/TlemProvider.java
index 8f40780c..2a6ff0cc 100644
--- a/enabler/src/de/schildbach/pte/TlemProvider.java
+++ b/enabler/src/de/schildbach/pte/TlemProvider.java
@@ -21,6 +21,8 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Line;
 import de.schildbach.pte.dto.Product;
 import de.schildbach.pte.dto.Style;
@@ -72,8 +74,8 @@ public class TlemProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("1".equals(mot))
 		{
diff --git a/enabler/src/de/schildbach/pte/VblProvider.java b/enabler/src/de/schildbach/pte/VblProvider.java
index 94190a0c..6d255ecc 100644
--- a/enabler/src/de/schildbach/pte/VblProvider.java
+++ b/enabler/src/de/schildbach/pte/VblProvider.java
@@ -17,6 +17,8 @@
 
 package de.schildbach.pte;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Line;
 import de.schildbach.pte.dto.Product;
 
@@ -41,8 +43,8 @@ public class VblProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("0".equals(mot))
 		{
diff --git a/enabler/src/de/schildbach/pte/VgnProvider.java b/enabler/src/de/schildbach/pte/VgnProvider.java
index 6df0d2f2..d12797dc 100644
--- a/enabler/src/de/schildbach/pte/VgnProvider.java
+++ b/enabler/src/de/schildbach/pte/VgnProvider.java
@@ -21,6 +21,8 @@ import java.util.Collection;
 import java.util.Date;
 import java.util.Set;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Line;
 import de.schildbach.pte.dto.Location;
 import de.schildbach.pte.dto.Product;
@@ -45,8 +47,8 @@ public class VgnProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("0".equals(mot))
 		{
@@ -62,8 +64,9 @@ public class VgnProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected String xsltTripRequestParameters(final Location from, final Location via, final Location to, final Date date, final boolean dep,
-			final Collection<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility, final Set<Option> options)
+	protected String xsltTripRequestParameters(final Location from, final @Nullable Location via, final Location to, final Date date,
+			final boolean dep, final @Nullable Collection<Product> products, final @Nullable WalkSpeed walkSpeed,
+			final @Nullable Accessibility accessibility, final @Nullable Set<Option> options)
 	{
 		return super.xsltTripRequestParameters(from, via, to, date, dep, products, walkSpeed, accessibility, options) + "&itdLPxx_showTariffLevel=1";
 	}
diff --git a/enabler/src/de/schildbach/pte/VmsProvider.java b/enabler/src/de/schildbach/pte/VmsProvider.java
index a53defae..1dde1bb7 100644
--- a/enabler/src/de/schildbach/pte/VmsProvider.java
+++ b/enabler/src/de/schildbach/pte/VmsProvider.java
@@ -17,6 +17,8 @@
 
 package de.schildbach.pte;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Line;
 import de.schildbach.pte.dto.Product;
 
@@ -39,8 +41,8 @@ public class VmsProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("0".equals(mot))
 		{
diff --git a/enabler/src/de/schildbach/pte/VrnProvider.java b/enabler/src/de/schildbach/pte/VrnProvider.java
index e669dc5a..75c73786 100644
--- a/enabler/src/de/schildbach/pte/VrnProvider.java
+++ b/enabler/src/de/schildbach/pte/VrnProvider.java
@@ -17,6 +17,8 @@
 
 package de.schildbach.pte;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.dto.Line;
 import de.schildbach.pte.dto.Product;
 
@@ -41,8 +43,8 @@ public class VrnProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("0".equals(mot))
 		{
diff --git a/enabler/src/de/schildbach/pte/VrrProvider.java b/enabler/src/de/schildbach/pte/VrrProvider.java
index 2bc2e742..8bef24a0 100644
--- a/enabler/src/de/schildbach/pte/VrrProvider.java
+++ b/enabler/src/de/schildbach/pte/VrrProvider.java
@@ -20,6 +20,8 @@ package de.schildbach.pte;
 import java.util.HashMap;
 import java.util.Map;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.Charsets;
 
 import de.schildbach.pte.dto.Line;
@@ -52,8 +54,8 @@ public class VrrProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("0".equals(mot))
 		{
@@ -190,7 +192,7 @@ public class VrrProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	public Style lineStyle(final String network, final Product product, final String label)
+	public Style lineStyle(final @Nullable String network, final @Nullable Product product, final @Nullable String label)
 	{
 		if (product == Product.BUS && label != null && label.startsWith("SB"))
 			return super.lineStyle(network, product, "SB");
diff --git a/enabler/src/de/schildbach/pte/VvoProvider.java b/enabler/src/de/schildbach/pte/VvoProvider.java
index e86bd6e1..72f71d2c 100644
--- a/enabler/src/de/schildbach/pte/VvoProvider.java
+++ b/enabler/src/de/schildbach/pte/VvoProvider.java
@@ -17,6 +17,8 @@
 
 package de.schildbach.pte;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.Charsets;
 
 import de.schildbach.pte.dto.Line;
@@ -49,8 +51,8 @@ public class VvoProvider extends AbstractEfaProvider
 	}
 
 	@Override
-	protected Line parseLine(final String id, final String mot, final String symbol, final String name, final String longName,
-			final String trainType, final String trainNum, final String trainName)
+	protected Line parseLine(final @Nullable String id, final @Nullable String mot, final @Nullable String symbol, final @Nullable String name,
+			final @Nullable String longName, final @Nullable String trainType, final @Nullable String trainNum, final @Nullable String trainName)
 	{
 		if ("0".equals(mot))
 		{
diff --git a/enabler/src/de/schildbach/pte/dto/Departure.java b/enabler/src/de/schildbach/pte/dto/Departure.java
index 21c2b527..51cd7986 100644
--- a/enabler/src/de/schildbach/pte/dto/Departure.java
+++ b/enabler/src/de/schildbach/pte/dto/Departure.java
@@ -25,6 +25,8 @@ import java.util.Comparator;
 import java.util.Date;
 import java.util.Locale;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.MoreObjects;
 import com.google.common.base.MoreObjects.ToStringHelper;
 import com.google.common.base.Objects;
@@ -34,13 +36,13 @@ import com.google.common.base.Objects;
  */
 public final class Departure implements Serializable
 {
-	final public Date plannedTime;
-	final public Date predictedTime;
+	final public @Nullable Date plannedTime;
+	final public @Nullable Date predictedTime;
 	final public Line line;
-	final public Position position;
-	final public Location destination;
-	final public int[] capacity;
-	final public String message;
+	final public @Nullable Position position;
+	final public @Nullable Location destination;
+	final public @Nullable int[] capacity;
+	final public @Nullable String message;
 
 	public Departure(final Date plannedTime, final Date predictedTime, final Line line, final Position position, final Location destination,
 			final int[] capacity, final String message)
diff --git a/enabler/src/de/schildbach/pte/dto/Fare.java b/enabler/src/de/schildbach/pte/dto/Fare.java
index f0e64b55..28530f84 100644
--- a/enabler/src/de/schildbach/pte/dto/Fare.java
+++ b/enabler/src/de/schildbach/pte/dto/Fare.java
@@ -22,6 +22,8 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import java.io.Serializable;
 import java.util.Currency;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 
@@ -39,8 +41,8 @@ public final class Fare implements Serializable
 	public final Type type;
 	public final Currency currency;
 	public final float fare;
-	public final String unitName;
-	public final String units;
+	public final @Nullable String unitName;
+	public final @Nullable String units;
 
 	public Fare(final String network, final Type type, final Currency currency, final float fare, final String unitName, final String units)
 	{
diff --git a/enabler/src/de/schildbach/pte/dto/Line.java b/enabler/src/de/schildbach/pte/dto/Line.java
index b502e702..43ef66bb 100644
--- a/enabler/src/de/schildbach/pte/dto/Line.java
+++ b/enabler/src/de/schildbach/pte/dto/Line.java
@@ -20,6 +20,8 @@ package de.schildbach.pte.dto;
 import java.io.Serializable;
 import java.util.Set;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 import com.google.common.collect.ComparisonChain;
@@ -37,12 +39,12 @@ public final class Line implements Serializable, Comparable<Line>
 
 	private static final long serialVersionUID = -5642533805998375070L;
 
-	public final String id;
-	public final Product product;
-	public final String label;
-	public final Style style;
-	public final Set<Attr> attrs;
-	public final String message;
+	public final @Nullable String id;
+	public final @Nullable Product product;
+	public final @Nullable String label;
+	public final @Nullable Style style;
+	public final @Nullable Set<Attr> attrs;
+	public final @Nullable String message;
 
 	public static final Line FOOTWAY = new Line(null, null, null);
 	public static final Line TRANSFER = new Line(null, null, null);
@@ -81,11 +83,13 @@ public final class Line implements Serializable, Comparable<Line>
 
 	public char productCode()
 	{
+		final Product product = this.product;
 		return product != null ? product.code : Product.UNKNOWN;
 	}
 
 	public boolean hasAttr(final Attr attr)
 	{
+		final Set<Attr> attrs = this.attrs;
 		return attrs != null && attrs.contains(attr);
 	}
 
diff --git a/enabler/src/de/schildbach/pte/dto/LineDestination.java b/enabler/src/de/schildbach/pte/dto/LineDestination.java
index 40f45566..60c44b06 100644
--- a/enabler/src/de/schildbach/pte/dto/LineDestination.java
+++ b/enabler/src/de/schildbach/pte/dto/LineDestination.java
@@ -21,6 +21,8 @@ import static com.google.common.base.Preconditions.checkNotNull;
 
 import java.io.Serializable;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 
@@ -30,7 +32,7 @@ import com.google.common.base.Objects;
 public final class LineDestination implements Serializable
 {
 	final public Line line;
-	final public Location destination;
+	final public @Nullable Location destination;
 
 	public LineDestination(final Line line, final Location destination)
 	{
diff --git a/enabler/src/de/schildbach/pte/dto/Location.java b/enabler/src/de/schildbach/pte/dto/Location.java
index af6dc314..c5b98016 100644
--- a/enabler/src/de/schildbach/pte/dto/Location.java
+++ b/enabler/src/de/schildbach/pte/dto/Location.java
@@ -23,6 +23,8 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import java.io.Serializable;
 import java.util.Arrays;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.MoreObjects;
 import com.google.common.base.MoreObjects.ToStringHelper;
 import com.google.common.base.Objects;
@@ -33,10 +35,10 @@ import com.google.common.base.Objects;
 public final class Location implements Serializable
 {
 	public final LocationType type;
-	public final String id;
+	public final @Nullable String id;
 	public final int lat, lon;
-	public final String place;
-	public final String name;
+	public final @Nullable String place;
+	public final @Nullable String name;
 
 	public Location(final LocationType type, final String id, final int lat, final int lon, final String place, final String name)
 	{
diff --git a/enabler/src/de/schildbach/pte/dto/NearbyLocationsResult.java b/enabler/src/de/schildbach/pte/dto/NearbyLocationsResult.java
index e36a7dab..9b0c8bce 100644
--- a/enabler/src/de/schildbach/pte/dto/NearbyLocationsResult.java
+++ b/enabler/src/de/schildbach/pte/dto/NearbyLocationsResult.java
@@ -22,6 +22,8 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import java.io.Serializable;
 import java.util.List;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.MoreObjects;
 import com.google.common.base.MoreObjects.ToStringHelper;
 
@@ -35,7 +37,7 @@ public final class NearbyLocationsResult implements Serializable
 		OK, INVALID_ID, SERVICE_DOWN
 	}
 
-	public final ResultHeader header;
+	public final @Nullable ResultHeader header;
 	public final Status status;
 	public final List<Location> locations;
 
diff --git a/enabler/src/de/schildbach/pte/dto/Position.java b/enabler/src/de/schildbach/pte/dto/Position.java
index 60053f10..c7c387cc 100644
--- a/enabler/src/de/schildbach/pte/dto/Position.java
+++ b/enabler/src/de/schildbach/pte/dto/Position.java
@@ -22,6 +22,8 @@ import static com.google.common.base.Preconditions.checkNotNull;
 
 import java.io.Serializable;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.Objects;
 
 /**
@@ -30,7 +32,7 @@ import com.google.common.base.Objects;
 public final class Position implements Serializable
 {
 	public final String name;
-	public final String section;
+	public final @Nullable String section;
 
 	public Position(final String name)
 	{
diff --git a/enabler/src/de/schildbach/pte/dto/QueryDeparturesResult.java b/enabler/src/de/schildbach/pte/dto/QueryDeparturesResult.java
index bbc127fa..464001fb 100644
--- a/enabler/src/de/schildbach/pte/dto/QueryDeparturesResult.java
+++ b/enabler/src/de/schildbach/pte/dto/QueryDeparturesResult.java
@@ -23,6 +23,8 @@ import java.io.Serializable;
 import java.util.LinkedList;
 import java.util.List;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.MoreObjects;
 import com.google.common.base.MoreObjects.ToStringHelper;
 
@@ -36,7 +38,7 @@ public final class QueryDeparturesResult implements Serializable
 		OK, INVALID_STATION, SERVICE_DOWN
 	}
 
-	public final ResultHeader header;
+	public final @Nullable ResultHeader header;
 	public final Status status;
 	public final List<StationDepartures> stationDepartures = new LinkedList<StationDepartures>();
 
@@ -56,7 +58,8 @@ public final class QueryDeparturesResult implements Serializable
 	{
 		for (final StationDepartures departures : stationDepartures)
 		{
-			if (stationId.equals(departures.location.id))
+			final Location location = departures.location;
+			if (location != null && stationId.equals(location.id))
 				return departures;
 		}
 
diff --git a/enabler/src/de/schildbach/pte/dto/QueryTripsResult.java b/enabler/src/de/schildbach/pte/dto/QueryTripsResult.java
index 111c8c1a..2291cf1d 100644
--- a/enabler/src/de/schildbach/pte/dto/QueryTripsResult.java
+++ b/enabler/src/de/schildbach/pte/dto/QueryTripsResult.java
@@ -22,6 +22,8 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import java.io.Serializable;
 import java.util.List;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.MoreObjects;
 import com.google.common.base.MoreObjects.ToStringHelper;
 
@@ -35,7 +37,7 @@ public final class QueryTripsResult implements Serializable
 		OK, AMBIGUOUS, TOO_CLOSE, UNKNOWN_FROM, UNKNOWN_VIA, UNKNOWN_TO, UNRESOLVABLE_ADDRESS, NO_TRIPS, INVALID_DATE, SERVICE_DOWN;
 	}
 
-	public final ResultHeader header;
+	public final @Nullable ResultHeader header;
 	public final Status status;
 
 	public final List<Location> ambiguousFrom;
diff --git a/enabler/src/de/schildbach/pte/dto/ResultHeader.java b/enabler/src/de/schildbach/pte/dto/ResultHeader.java
index e5ff002c..8301b153 100644
--- a/enabler/src/de/schildbach/pte/dto/ResultHeader.java
+++ b/enabler/src/de/schildbach/pte/dto/ResultHeader.java
@@ -21,6 +21,8 @@ import static com.google.common.base.Preconditions.checkNotNull;
 
 import java.io.Serializable;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.MoreObjects;
 
 /**
@@ -29,7 +31,7 @@ import com.google.common.base.MoreObjects;
 public final class ResultHeader implements Serializable
 {
 	public final String serverProduct;
-	public final String serverVersion;
+	public final @Nullable String serverVersion;
 	public final long serverTime;
 	public final Object context;
 
diff --git a/enabler/src/de/schildbach/pte/dto/StationDepartures.java b/enabler/src/de/schildbach/pte/dto/StationDepartures.java
index 780441c7..731b7794 100644
--- a/enabler/src/de/schildbach/pte/dto/StationDepartures.java
+++ b/enabler/src/de/schildbach/pte/dto/StationDepartures.java
@@ -22,6 +22,8 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import java.io.Serializable;
 import java.util.List;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.MoreObjects;
 import com.google.common.base.MoreObjects.ToStringHelper;
 import com.google.common.base.Objects;
@@ -33,7 +35,7 @@ public final class StationDepartures implements Serializable
 {
 	public final Location location;
 	public final List<Departure> departures;
-	public final List<LineDestination> lines;
+	public final @Nullable List<LineDestination> lines;
 
 	public StationDepartures(final Location location, final List<Departure> departures, final List<LineDestination> lines)
 	{
diff --git a/enabler/src/de/schildbach/pte/dto/Stop.java b/enabler/src/de/schildbach/pte/dto/Stop.java
index f8f3bc9a..721e56d6 100644
--- a/enabler/src/de/schildbach/pte/dto/Stop.java
+++ b/enabler/src/de/schildbach/pte/dto/Stop.java
@@ -23,6 +23,8 @@ import java.io.Serializable;
 import java.util.Date;
 import java.util.Locale;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.MoreObjects;
 import com.google.common.base.MoreObjects.ToStringHelper;
 import com.google.common.base.Objects;
@@ -33,15 +35,15 @@ import com.google.common.base.Objects;
 public final class Stop implements Serializable
 {
 	public final Location location;
-	public final Date plannedArrivalTime;
-	public final Date predictedArrivalTime;
-	public final Position plannedArrivalPosition;
-	public final Position predictedArrivalPosition;
+	public final @Nullable Date plannedArrivalTime;
+	public final @Nullable Date predictedArrivalTime;
+	public final @Nullable Position plannedArrivalPosition;
+	public final @Nullable Position predictedArrivalPosition;
 	public final boolean arrivalCancelled;
-	public final Date plannedDepartureTime;
-	public final Date predictedDepartureTime;
-	public final Position plannedDeparturePosition;
-	public final Position predictedDeparturePosition;
+	public final @Nullable Date plannedDepartureTime;
+	public final @Nullable Date predictedDepartureTime;
+	public final @Nullable Position plannedDeparturePosition;
+	public final @Nullable Position predictedDeparturePosition;
 	public final boolean departureCancelled;
 
 	public Stop(final Location location, final Date plannedArrivalTime, final Date predictedArrivalTime, final Position plannedArrivalPosition,
@@ -125,6 +127,8 @@ public final class Stop implements Serializable
 
 	public Long getArrivalDelay()
 	{
+		final Date plannedArrivalTime = this.plannedArrivalTime;
+		final Date predictedArrivalTime = this.predictedArrivalTime;
 		if (plannedArrivalTime != null && predictedArrivalTime != null)
 			return predictedArrivalTime.getTime() - plannedArrivalTime.getTime();
 		else
@@ -163,6 +167,8 @@ public final class Stop implements Serializable
 
 	public Long getDepartureDelay()
 	{
+		final Date plannedDepartureTime = this.plannedDepartureTime;
+		final Date predictedDepartureTime = this.predictedDepartureTime;
 		if (plannedDepartureTime != null && predictedDepartureTime != null)
 			return predictedDepartureTime.getTime() - plannedDepartureTime.getTime();
 		else
@@ -186,6 +192,7 @@ public final class Stop implements Serializable
 
 	public Date getMinTime()
 	{
+		final Date predictedDepartureTime = this.predictedDepartureTime;
 		if (plannedDepartureTime == null || (predictedDepartureTime != null && predictedDepartureTime.before(plannedDepartureTime)))
 			return predictedDepartureTime;
 		else
@@ -194,6 +201,7 @@ public final class Stop implements Serializable
 
 	public Date getMaxTime()
 	{
+		final Date predictedArrivalTime = this.predictedArrivalTime;
 		if (plannedArrivalTime == null || (predictedArrivalTime != null && predictedArrivalTime.after(plannedArrivalTime)))
 			return predictedArrivalTime;
 		else
diff --git a/enabler/src/de/schildbach/pte/dto/SuggestLocationsResult.java b/enabler/src/de/schildbach/pte/dto/SuggestLocationsResult.java
index 4a48214d..9c92a1dc 100644
--- a/enabler/src/de/schildbach/pte/dto/SuggestLocationsResult.java
+++ b/enabler/src/de/schildbach/pte/dto/SuggestLocationsResult.java
@@ -25,6 +25,8 @@ import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.MoreObjects;
 import com.google.common.base.MoreObjects.ToStringHelper;
 
@@ -38,7 +40,7 @@ public final class SuggestLocationsResult implements Serializable
 		OK, SERVICE_DOWN
 	}
 
-	public final ResultHeader header;
+	public final @Nullable ResultHeader header;
 	public final Status status;
 	private final List<SuggestedLocation> suggestedLocations;
 
diff --git a/enabler/src/de/schildbach/pte/dto/Trip.java b/enabler/src/de/schildbach/pte/dto/Trip.java
index f349301e..7b253871 100644
--- a/enabler/src/de/schildbach/pte/dto/Trip.java
+++ b/enabler/src/de/schildbach/pte/dto/Trip.java
@@ -27,6 +27,8 @@ import java.util.List;
 import java.util.Locale;
 import java.util.Set;
 
+import javax.annotation.Nullable;
+
 import com.google.common.base.MoreObjects;
 import com.google.common.base.MoreObjects.ToStringHelper;
 import com.google.common.base.Objects;
@@ -65,7 +67,7 @@ public final class Trip implements Serializable
 		return legs.get(0).getDepartureTime();
 	}
 
-	public Public getFirstPublicLeg()
+	public @Nullable Public getFirstPublicLeg()
 	{
 		for (final Leg leg : legs)
 			if (leg instanceof Public)
@@ -74,7 +76,7 @@ public final class Trip implements Serializable
 		return null;
 	}
 
-	public Date getFirstPublicLegDepartureTime()
+	public @Nullable Date getFirstPublicLegDepartureTime()
 	{
 		final Public firstPublicLeg = getFirstPublicLeg();
 		if (firstPublicLeg != null)
@@ -88,7 +90,7 @@ public final class Trip implements Serializable
 		return legs.get(legs.size() - 1).getArrivalTime();
 	}
 
-	public Public getLastPublicLeg()
+	public @Nullable Public getLastPublicLeg()
 	{
 		for (int i = legs.size() - 1; i >= 0; i--)
 		{
@@ -100,7 +102,7 @@ public final class Trip implements Serializable
 		return null;
 	}
 
-	public Date getLastPublicLegArrivalTime()
+	public @Nullable Date getLastPublicLegArrivalTime()
 	{
 		final Public lastPublicLeg = getLastPublicLeg();
 		if (lastPublicLeg != null)
@@ -127,7 +129,7 @@ public final class Trip implements Serializable
 	 * 
 	 * @return duration in ms, or null if there are no public legs
 	 */
-	public Long getPublicDuration()
+	public @Nullable Long getPublicDuration()
 	{
 		final Date first = getFirstPublicLegDepartureTime();
 		final Date last = getLastPublicLegArrivalTime();
@@ -217,8 +219,12 @@ public final class Trip implements Serializable
 			else if (leg instanceof Public)
 			{
 				final Public publicLeg = (Public) leg;
-				builder.append(publicLeg.departureStop.plannedDepartureTime.getTime()).append('-');
-				builder.append(publicLeg.arrivalStop.plannedArrivalTime.getTime()).append('-');
+				final Date plannedDepartureTime = publicLeg.departureStop.plannedDepartureTime;
+				if (plannedDepartureTime != null)
+					builder.append(plannedDepartureTime.getTime()).append('-');
+				final Date plannedArrivalTime = publicLeg.arrivalStop.plannedArrivalTime;
+				if (plannedArrivalTime != null)
+					builder.append(plannedArrivalTime.getTime()).append('-');
 				final Line line = publicLeg.line;
 				builder.append(line.productCode());
 				builder.append(line.label);
@@ -294,11 +300,11 @@ public final class Trip implements Serializable
 		private static final long serialVersionUID = 1312066446239817422L;
 
 		public final Line line;
-		public final Location destination;
+		public final @Nullable Location destination;
 		public final Stop departureStop;
 		public final Stop arrivalStop;
-		public final List<Stop> intermediateStops;
-		public final String message;
+		public final @Nullable List<Stop> intermediateStops;
+		public final @Nullable String message;
 
 		public Public(final Line line, final Location destination, final Stop departureStop, final Stop arrivalStop,
 				final List<Stop> intermediateStops, final List<Point> path, final String message)
diff --git a/enabler/src/de/schildbach/pte/util/XmlPullUtil.java b/enabler/src/de/schildbach/pte/util/XmlPullUtil.java
index 97d4ee2d..75d49e02 100644
--- a/enabler/src/de/schildbach/pte/util/XmlPullUtil.java
+++ b/enabler/src/de/schildbach/pte/util/XmlPullUtil.java
@@ -7,6 +7,8 @@ package de.schildbach.pte.util;
 
 import java.io.IOException;
 
+import javax.annotation.Nullable;
+
 import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlPullParserException;
 
@@ -131,7 +133,7 @@ public final class XmlPullUtil
 			throw new IllegalStateException("expecting attribute: " + attrName);
 	}
 
-	public static String optAttr(final XmlPullParser pp, final String attrName, final String defaultValue)
+	public static String optAttr(final XmlPullParser pp, final String attrName, final @Nullable String defaultValue)
 	{
 		final String attr = pp.getAttributeValue(null, attrName);
 
@@ -189,8 +191,8 @@ public final class XmlPullUtil
 		return value != null ? value.trim() : null;
 	}
 
-	public static String optValueTag(final XmlPullParser pp, final String tagName, final String defaultValue) throws XmlPullParserException,
-			IOException
+	public static String optValueTag(final XmlPullParser pp, final String tagName, final @Nullable String defaultValue)
+			throws XmlPullParserException, IOException
 	{
 		if (XmlPullUtil.test(pp, tagName))
 		{
@@ -236,9 +238,6 @@ public final class XmlPullUtil
 
 	public static String nextText(final XmlPullParser pp, final String namespace, final String name) throws IOException, XmlPullParserException
 	{
-		if (name == null)
-			throw new XmlPullParserException("name for element can not be null");
-
 		pp.require(XmlPullParser.START_TAG, namespace, name);
 		final String text = pp.nextText();
 
diff --git a/enabler/test/de/schildbach/pte/live/AbstractProviderLiveTest.java b/enabler/test/de/schildbach/pte/live/AbstractProviderLiveTest.java
index bc4b78c3..2cdcba22 100644
--- a/enabler/test/de/schildbach/pte/live/AbstractProviderLiveTest.java
+++ b/enabler/test/de/schildbach/pte/live/AbstractProviderLiveTest.java
@@ -24,6 +24,8 @@ import java.util.Date;
 import java.util.EnumSet;
 import java.util.Set;
 
+import javax.annotation.Nullable;
+
 import de.schildbach.pte.NetworkProvider;
 import de.schildbach.pte.NetworkProvider.Accessibility;
 import de.schildbach.pte.NetworkProvider.WalkSpeed;
@@ -126,8 +128,9 @@ public abstract class AbstractProviderLiveTest
 		return provider.suggestLocations(constraint);
 	}
 
-	protected final QueryTripsResult queryTrips(final Location from, final Location via, final Location to, final Date date, final boolean dep,
-			final Set<Product> products, final WalkSpeed walkSpeed, final Accessibility accessibility) throws IOException
+	protected final QueryTripsResult queryTrips(final Location from, final @Nullable Location via, final Location to, final Date date,
+			final boolean dep, final @Nullable Set<Product> products, final @Nullable WalkSpeed walkSpeed, final @Nullable Accessibility accessibility)
+			throws IOException
 	{
 		return provider.queryTrips(from, via, to, date, dep, products, walkSpeed, accessibility, null);
 	}
diff --git a/enabler/test/de/schildbach/pte/live/ParisProviderLiveTest.java b/enabler/test/de/schildbach/pte/live/ParisProviderLiveTest.java
index 73988c93..9c27f970 100644
--- a/enabler/test/de/schildbach/pte/live/ParisProviderLiveTest.java
+++ b/enabler/test/de/schildbach/pte/live/ParisProviderLiveTest.java
@@ -18,17 +18,20 @@
 package de.schildbach.pte.live;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 
 import java.util.Calendar;
 import java.util.Date;
 import java.util.EnumSet;
+import java.util.List;
 
 import org.junit.Test;
 
 import de.schildbach.pte.NetworkProvider.Accessibility;
 import de.schildbach.pte.NetworkProvider.WalkSpeed;
 import de.schildbach.pte.ParisProvider;
+import de.schildbach.pte.dto.LineDestination;
 import de.schildbach.pte.dto.Location;
 import de.schildbach.pte.dto.LocationType;
 import de.schildbach.pte.dto.NearbyLocationsResult;
@@ -103,7 +106,9 @@ public class ParisProviderLiveTest extends AbstractProviderLiveTest
 		assertEquals(QueryDeparturesResult.Status.OK, result.status);
 		assertEquals(1, result.stationDepartures.size());
 		assertTrue(result.stationDepartures.get(0).departures.size() <= maxDepartures);
-		assertTrue(result.stationDepartures.get(0).lines.size() >= 1);
+		final List<LineDestination> lines = result.stationDepartures.get(0).lines;
+		assertNotNull(lines);
+		assertTrue(lines.size() >= 1);
 		print(result);
 	}
 
@@ -119,7 +124,9 @@ public class ParisProviderLiveTest extends AbstractProviderLiveTest
 		for (StationDepartures stationDepartures : result.stationDepartures)
 		{
 			nbDepartures += stationDepartures.departures.size();
-			nbLines += stationDepartures.lines.size();
+			final List<LineDestination> lines = stationDepartures.lines;
+			assertNotNull(lines);
+			nbLines += lines.size();
 		}
 		assertTrue(nbDepartures <= maxDepartures);
 		assertTrue(nbLines >= 2);