196 station status or vehicle status should be required

example/pom.xml

@@ -20,7 +20,7 @@
         <maven.compiler.target>17</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <!-- To use a snapshot, change this to e.g. 3.0.4-SNAPSHOT -->
-        <gbfs-validator.version>3.0.3</gbfs-validator.version>
+        <gbfs-validator.version>3.1.0</gbfs-validator.version>
     </properties>
 
     <repositories>
@@ -44,6 +44,12 @@
             <artifactId>gbfs-validator-java</artifactId>
             <version>${gbfs-validator.version}</version>
         </dependency>
+        <!-- Loader: fetches gbfs.json and all linked feed files automatically -->
+        <dependency>
+            <groupId>org.mobilitydata</groupId>
+            <artifactId>gbfs-validator-java-loader</artifactId>
+            <version>${gbfs-validator.version}</version>
+        </dependency>
     </dependencies>
 
 

example/src/main/java/org/mobilitydata/gbfs/validator/example/GbfsValidatorExample.java

@@ -9,21 +9,25 @@
 import java.net.http.HttpResponse;
 import java.nio.charset.StandardCharsets;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import org.mobilitydata.gbfs.validation.GbfsValidator;
 import org.mobilitydata.gbfs.validation.GbfsValidatorFactory;
 import org.mobilitydata.gbfs.validation.model.FileValidationError;
 import org.mobilitydata.gbfs.validation.model.FileValidationResult;
 import org.mobilitydata.gbfs.validation.model.ValidationResult;
+import org.mobilitydata.gbfs.validator.loader.LoadedFile;
+import org.mobilitydata.gbfs.validator.loader.Loader;
 
 /**
  * Example showing how to validate a GBFS feed using gbfs-validator-java.
  *
- * <p>This example:
+ * <p>Two use cases are demonstrated:
  * <ol>
- *   <li>Fetches gbfs.json from a public GBFS feed</li>
- *   <li>Validates the file using GbfsValidatorFactory</li>
- *   <li>Prints the validation results to stdout</li>
+ *   <li>Single-file validation via {@link GbfsValidator#validateFile}</li>
+ *   <li>Full-feed validation via {@link Loader} + {@link GbfsValidator#validate}:
+ *       the Loader fetches gbfs.json and automatically discovers and loads all
+ *       linked feed files, so no manual URL construction is needed.</li>
  * </ol>
  *
  * <p>Usage:
@@ -42,57 +46,54 @@ public class GbfsValidatorExample {
     public static void main(String[] args) throws IOException, InterruptedException {
         System.out.println("=== GBFS Validator Java Example ===\n");
 
+        GbfsValidator validator = GbfsValidatorFactory.getGbfsJsonValidator();
+
         // --- Example 1: Validate a single file ---
+        // Useful when you already have the file content and just want schema validation.
         System.out.println("Example 1: Validate a single file");
         System.out.println("Fetching: " + GBFS_FEED_URL);
-        String fileContents = fetchUrl(GBFS_FEED_URL);
-
-        GbfsValidator validator = GbfsValidatorFactory.getGbfsJsonValidator();
-        InputStream fileStream = new ByteArrayInputStream(
-            fileContents.getBytes(StandardCharsets.UTF_8)
-        );
-
-        // The API expects file names WITHOUT the .json extension (e.g. "gbfs", not "gbfs.json")
-        FileValidationResult fileResult = validator.validateFile("gbfs", fileStream);
+        String gbfsContent = fetchUrl(GBFS_FEED_URL);
+        InputStream gbfsStream = new ByteArrayInputStream(gbfsContent.getBytes(StandardCharsets.UTF_8));
+        FileValidationResult fileResult = validator.validateFile("gbfs", gbfsStream);
         printFileResult(fileResult);
 
-        // --- Example 2: Validate a full feed (multiple files) ---
+        // --- Example 2: Validate a full feed ---
+        // The Loader fetches gbfs.json, parses the feed URLs from its discovery data,
+        // and loads all linked files — handling language prefixes and auth automatically.
         System.out.println("\nExample 2: Validate a full feed");
-        Map<String, InputStream> feedFiles = new HashMap<>();
-
-        // Keys must be the GBFS file type name (no .json extension)
-        feedFiles.put("gbfs", new ByteArrayInputStream(
-            fileContents.getBytes(StandardCharsets.UTF_8)
-        ));
-
-        // Fetch additional files — URL uses .json, but map key does not
-        String[] additionalFileNames = {
-            "system_information",
-            "station_information",
-            "station_status",
-            "free_bike_status",
-        };
-        String baseUrl = GBFS_FEED_URL.substring(0, GBFS_FEED_URL.lastIndexOf('/') + 1);
-        for (String fileType : additionalFileNames) {
-            try {
-                String content = fetchUrl(baseUrl + fileType + ".json");
-                feedFiles.put(fileType, new ByteArrayInputStream(
-                    content.getBytes(StandardCharsets.UTF_8)
-                ));
-                System.out.println("  Loaded: " + fileType);
-            } catch (Exception e) {
-                System.out.println("  Skipped: " + fileType + " (" + e.getMessage() + ")");
+        Loader loader = new Loader();
+        try {
+            List<LoadedFile> loadedFiles = loader.load(GBFS_FEED_URL);
+
+            Map<String, InputStream> fileMap = new HashMap<>();
+            for (LoadedFile file : loadedFiles) {
+                // Keep the discovery file (no language) and only "en" language files.
+                // If a feed does not publish "en", swap "en" for the desired language code.
+                String lang = file.language();
+                if (lang != null && !lang.equals("en")) {
+                    continue;
+                }
+                if (file.fileContents() != null) {
+                    System.out.println("  Loaded: " + file.fileName() + " (" + file.url() + ")");
+                    fileMap.put(file.fileName(), file.fileContents());
+                } else {
+                    file.loaderErrors().forEach(e ->
+                        System.out.println("  Skipped: " + file.fileName()
+                            + " (" + e.error() + ": " + e.message() + ")")
+                    );
+                }
             }
-        }
 
-        ValidationResult feedResult = validator.validate(feedFiles);
-        printFeedResult(feedResult);
+            ValidationResult feedResult = validator.validate(fileMap);
+            printFeedResult(feedResult);
+        } finally {
+            loader.close();
+        }
     }
 
     private static void printFileResult(FileValidationResult result) {
         System.out.println("  File    : " + result.file());
         System.out.println("  Version : " + result.version());
-        System.out.println("  Schema  : " + result.schema());
         System.out.println("  Exists  : " + result.exists());
         System.out.println("  Required: " + result.required());
         System.out.println("  Errors  : " + result.errorsCount());
@@ -115,14 +116,17 @@ private static void printFileResult(FileValidationResult result) {
 
     private static void printFeedResult(ValidationResult result) {
         System.out.println("  Summary : " + result.summary());
-        System.out.println("  Files validated: " + result.files().size());
-        result.files().forEach((name, fileResult) -> {
+        var presentFiles = result.files().entrySet().stream()
+            .filter(e -> e.getValue().exists())
+            .toList();
+        System.out.println("  Files validated: " + presentFiles.size());
+        presentFiles.forEach(e -> {
             System.out.printf("    %-35s errors=%d  version=%s%n",
-                name, fileResult.errorsCount(), fileResult.version());
+                e.getKey(), e.getValue().errorsCount(), e.getValue().version());
         });
 
-        long totalErrors = result.files().values().stream()
-            .mapToLong(FileValidationResult::errorsCount)
+        long totalErrors = presentFiles.stream()
+            .mapToLong(e -> e.getValue().errorsCount())
             .sum();
         System.out.println("\n  Total errors across all files: " + totalErrors);
 
@@ -139,12 +143,11 @@ private static String fetchUrl(String url) throws IOException, InterruptedExcept
             .uri(URI.create(url))
             .GET()
             .build();
-        HttpResponse<String> response = client.send(
-            request, HttpResponse.BodyHandlers.ofString()
-        );
+        HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
         if (response.statusCode() != 200) {
             throw new IOException("HTTP " + response.statusCode() + " for " + url);
         }
         return response.body();
     }
 }
+

gbfs-validator-java-cli/src/main/java/org/mobilitydata/gbfs/validator/cli/formatter/ConsoleReportFormatter.java

@@ -82,6 +82,8 @@ public String format(
 
       if (fileResult.required()) {
         sb.append(" [REQUIRED]");
+      } else if (fileResult.conditionallyRequired()) {
+        sb.append(" [CONDITIONALLY REQUIRED]");
       }
 
       if (!fileResult.exists()) {

gbfs-validator-java/src/main/java/org/mobilitydata/gbfs/validation/model/FileValidationResult.java

@@ -27,6 +27,8 @@
  * The result of validating a single GBFS file
  * @param file The name of the file that was validated
  * @param required Whether the file is required in the given version of GBFS
+ * @param conditionallyRequired Whether the file is conditionally required (e.g. station_status or
+ *        vehicle_status must be present — neither is individually required, but at least one must exist)
  * @param exists Whether the file existed in the validation input
  * @param errorsCount The number of errors found while validating the file
  * @param schema The schema used to validate the file
@@ -38,6 +40,7 @@
 public record FileValidationResult(
   String file,
   boolean required,
+  boolean conditionallyRequired,
   boolean exists,
   int errorsCount,
   String schema,
@@ -61,6 +64,8 @@ public String toString() {
       '\'' +
       ", required=" +
       required +
+      ", conditionallyRequired=" +
+      conditionallyRequired +
       ", exists=" +
       exists +
       ", errorsCount=" +
@@ -86,6 +91,7 @@ public String toString() {
   public boolean sameAs(FileValidationResult other) {
     if (other == null) return false;
     if (required != other.required) return false;
+    if (conditionallyRequired != other.conditionallyRequired) return false;
     if (exists != other.exists) return false;
     if (errorsCount != other.errorsCount) return false; // This should ideally reflect both validation and system errors count
     if (!Objects.equals(file, other.file)) return false;

gbfs-validator-java/src/main/java/org/mobilitydata/gbfs/validation/validator/FileValidator.java

@@ -80,13 +80,14 @@ public FileValidationResult validate(
       return new FileValidationResult(
         feedName,
         isRequired(feedName),
+        false,
         feed != null,
         errorsCount,
         schema.toString(),
         Optional.ofNullable(feed).map(JSONObject::toString).orElse(null),
         version.getVersionString(),
         validationErrors,
-        java.util.Collections.emptyList() // Added for systemErrors
+        java.util.Collections.emptyList()
       );
     }
 
@@ -130,6 +131,7 @@ public FileValidationResult validateMissingFile(String file) {
       file,
       isRequired,
       false,
+      false,
       isRequired ? 1 : 0,
       version.getSchema(file).toString(),
       null,

gbfs-validator-java/src/main/java/org/mobilitydata/gbfs/validation/validator/GbfsJsonValidator.java

@@ -131,6 +131,7 @@ public ValidationResult validate(Map<String, InputStream> rawFeeds) {
 
     List<String> missingFiles = findMissingFiles(version, fileValidations);
     handleMissingFiles(fileValidations, missingFiles, version); // This creates FVRs for missing files
+    checkStatusFilePresence(fileValidations, version);
 
     ValidationSummary summary = new ValidationSummary(
       version.getVersionString(),
@@ -147,6 +148,60 @@ public ValidationResult validate(Map<String, InputStream> rawFeeds) {
     return new ValidationResult(summary, fileValidations);
   }
 
+  /**
+   * Per GBFS spec, a feed must be dock-based, free-floating, or hybrid, so at least one of
+   * station_status / vehicle_status (v3+) or station_status / free_bike_status (pre-v3) must
+   * be present. If neither is present, both are flagged as required with an error.
+   */
+  private void checkStatusFilePresence(
+    Map<String, FileValidationResult> fileValidations,
+    Version version
+  ) {
+    String freeFloatingFile = version.getFileNames().contains("vehicle_status")
+      ? "vehicle_status"
+      : "free_bike_status";
+
+    boolean stationStatusAbsent = !isPresent(fileValidations, "station_status");
+    boolean freeFloatingAbsent = !isPresent(fileValidations, freeFloatingFile);
+
+    if (stationStatusAbsent && freeFloatingAbsent) {
+      markAsConditionallyRequired(fileValidations, "station_status");
+      markAsConditionallyRequired(fileValidations, freeFloatingFile);
+    }
+  }
+
+  private boolean isPresent(
+    Map<String, FileValidationResult> fileValidations,
+    String file
+  ) {
+    FileValidationResult result = fileValidations.get(file);
+    return result != null && result.exists();
+  }
+
+  private void markAsConditionallyRequired(
+    Map<String, FileValidationResult> fileValidations,
+    String file
+  ) {
+    FileValidationResult existing = fileValidations.get(file);
+    if (existing != null) {
+      fileValidations.put(
+        file,
+        new FileValidationResult(
+          existing.file(),
+          false,
+          true,
+          false,
+          1,
+          existing.schema(),
+          null,
+          existing.version(),
+          Collections.emptyList(),
+          Collections.emptyList()
+        )
+      );
+    }
+  }
+
   private Version detectVersionFromParsedFeeds(
     Map<String, ParsedFeedContainer> parsedFeeds
   ) {
@@ -357,6 +412,7 @@ private FileValidationResult createParsingErrorResult(
     return new FileValidationResult(
       feedName,
       supportedFeed && schemaVersion.isFileRequired(feedName),
+      false,
       true,
       0,
       supportedFeed ? schemaVersion.getSchema(feedName).toString() : null,

gbfs-validator-java/src/test/java/org/mobilitydata/gbfs/validation/model/ValidationResultTest.java

@@ -64,6 +64,7 @@ private FileValidationResult generateFileValidationResult(
     return new FileValidationResult(
       "gbfs",
       true,
+      false,
       true,
       2,
       null,