Sort GTFS files alphabetically inside GtfsModule

src/main/java/org/opentripplanner/graph_builder/model/GtfsBundle.java

@@ -21,6 +21,7 @@ public class GtfsBundle {
 
     private static final Logger LOG = LoggerFactory.getLogger(GtfsBundle.class);
 
+
     private File path;
 
     private URL url;
@@ -64,6 +65,8 @@ public GtfsBundle(File gtfsFile) {
         this.setPath(gtfsFile);
     }
 
+    public File getPath() { return path; }
+
     public void setPath(File path) {
         this.path = path;
     }

src/main/java/org/opentripplanner/graph_builder/module/GtfsModule.java

@@ -4,13 +4,8 @@
 import java.io.File;
 import java.io.IOException;
 import java.io.Serializable;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
+import java.util.*;
+import java.util.stream.Collectors;
 
 import org.onebusaway.csv_entities.EntityHandler;
 import org.onebusaway.gtfs.impl.GtfsRelationalDaoImpl;
@@ -64,9 +59,21 @@ public class GtfsModule implements GraphBuilderModule {
 
     int nextAgencyId = 1; // used for generating agency IDs to resolve ID conflicts
 
-    public List<GtfsBundle> gtfsBundles;
 
-    public GtfsModule(List<GtfsBundle> bundles) { this.gtfsBundles = bundles; }
+
+    private List<GtfsBundle> gtfsBundles;
+
+    public Boolean getUseCached() {
+        return useCached;
+    }
+
+    private Comparator<GtfsBundle> compareByFileName = Comparator.comparing(bundle -> bundle.getPath().getName());
+
+    public GtfsModule(List<GtfsBundle> bundles) {
+        List<GtfsBundle> defensiveCopy = new ArrayList<>(bundles);
+        defensiveCopy.sort(compareByFileName);
+        this.gtfsBundles = defensiveCopy;
+    }
 
     public List<String> provides() {
         List<String> result = new ArrayList<String>();
@@ -95,6 +102,8 @@ public void buildGraph(Graph graph, HashMap<Class<?>, Object> extra) {
         GtfsStopContext stopContext = new GtfsStopContext();
 
         try {
+            String fileNames = gtfsBundles.stream().map(b -> b.getPath().getName()).collect(Collectors.joining(", "));
+            LOG.info("Processing GTFS files in the following order: {}", fileNames);
             for (GtfsBundle gtfsBundle : gtfsBundles) {
                 // apply global defaults to individual GTFSBundles (if globals have been set)
                 if (cacheDirectory != null && gtfsBundle.cacheDirectory == null) {
@@ -392,4 +401,7 @@ public void checkInputs() {
         }
     }
 
+    public List<GtfsBundle> getGtfsBundles() {
+        return Collections.unmodifiableList(gtfsBundles);
+    }
 }

src/test/java/org/opentripplanner/graph_builder/module/GtfsModuleTest.java

@@ -0,0 +1,29 @@
+package org.opentripplanner.graph_builder.module;
+
+import com.google.common.collect.ImmutableList;
+import org.junit.Test;
+import org.opentripplanner.graph_builder.model.GtfsBundle;
+
+import java.io.File;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+
+public class GtfsModuleTest {
+
+    @Test
+    public void shouldSortByFileNameAlphabetically() {
+        List<GtfsBundle> bundles = ImmutableList.of("C.gtfs", "c.gtfs", "/tmp/z.gtfs", "/x-files/001-a.gtfs", "/some/other/folder/b.gtfs")
+                .stream()
+                .map(name -> new GtfsBundle(new File(name))).collect(Collectors.toList());
+
+        GtfsModule module = new GtfsModule(bundles);
+
+        List<String> names = module.getGtfsBundles().stream().map(m -> m.getPath().getName()).collect(Collectors.toList());
+
+        assertThat(names, is(ImmutableList.of("001-a.gtfs", "C.gtfs", "b.gtfs", "c.gtfs", "z.gtfs")));
+
+    }
+}