Fix NPE when having feeds with and without emissions.txt

Author: leonardehrenfried

application/src/ext/java/org/opentripplanner/ext/emissions/Co2EmissionsDataReader.java

@@ -35,13 +35,13 @@ public Map<FeedScopedId, Double> read(CompositeDataSource catalog, String resolv
     try {
       var emissionsDataSource = catalog.entry(EMISSIONS_FILE_NAME);
 
-      if (emissionsDataSource.exists()) {
+      if (emissionsDataSource != null && emissionsDataSource.exists()) {
         return readEmissions(emissionsDataSource.asInputStream(), resolvedFeedId);
       } else {
         return Map.of();
       }
     } catch (IOException e) {
-      LOG.error("Failed to read emission data. Details: " + e.getMessage(), e);
+      LOG.error("Failed to read emission data. Details: {}", e.getMessage(), e);
       return Map.of();
     }
   }
@@ -100,19 +100,6 @@ private Map<FeedScopedId, Double> readEmissions(InputStream stream, String feedI
     return emissionsData;
   }
 
-  private String readFeedId(InputStream stream) {
-    try {
-      CsvReader reader = new CsvReader(stream, StandardCharsets.UTF_8);
-      reader.readHeaders();
-      reader.readRecord();
-      return reader.get("feed_id");
-    } catch (IOException e) {
-      issueStore.add("InvalidEmissionData", "Reading feed_info.txt failed.");
-      LOG.error("InvalidEmissionData: reading feed_info.txt failed.", e);
-      throw new RuntimeException(e);
-    }
-  }
-
   private Optional<Double> calculateEmissionsPerPassengerPerMeter(
     String routeId,
     double avgCo2PerVehiclePerMeter,

application/src/main/java/org/opentripplanner/datastore/api/CompositeDataSource.java

@@ -2,6 +2,7 @@
 
 import java.io.Closeable;
 import java.util.Collection;
+import javax.annotation.Nullable;
 
 /**
  * A composite data source contain a collection of other {@link DataSource}s.
@@ -24,6 +25,7 @@ public interface CompositeDataSource extends DataSource, Closeable {
    * <p>
    * {@code DataSource routesSrc = gtfsSource.entry("routes.txt")}
    */
+  @Nullable
   DataSource entry(String name);
 
   /**