fix: always close the ZIP file after reading

src/main/java/com/adobe/epubcheck/ocf/OCFChecker.java

@@ -233,6 +233,18 @@ public boolean apply(OPFHandler opfHandler)
     //
     checkFileExtension(state);
 
+    // Close zip file to free resource
+    if (state.getZipResources() != null)
+    {
+      try
+      {
+        state.getZipResources().close();
+      }
+      catch (Exception e)
+      {
+        // FIXME 2023 - Inability to close zip file should be handled
+      }
+    }
   }
 
   private boolean checkContainerFile(OCFCheckerState state)
@@ -265,7 +277,9 @@ private boolean checkContainerStructure(OCFCheckerState state)
     {
       // FIXME 2022 build resourcesProvider depending on MIME type
       // Get a container
-      Iterable<OCFResource> resourcesProvider = new OCFZipResources(context.url);
+      OCFZipResources resourcesProvider = new OCFZipResources(context.url);
+      // Store the OCFZipResources object so it can be closed later
+      state.setZipResources(resourcesProvider);
       // Set to store the normalized paths for duplicate checks
       final Set<String> normalizedPaths = new HashSet<>();
       // Lists to store the container entries for later empty directory check

src/main/java/com/adobe/epubcheck/ocf/OCFCheckerState.java

@@ -41,6 +41,8 @@ class OCFCheckerState
   private final ImmutableList.Builder<URL> packageDocuments = ImmutableList.builder();
   private URL mappingDocument;
 
+  private OCFZipResources zipResources = null;
+
   private final Map<URL, EPUBLocation> obfuscated = new HashMap<>();
   private final Map<URL, Set<PublicationType>> publicationTypes = new LinkedHashMap<>();
   private final Map<URL, String> publicationIDs = new LinkedHashMap<>();
@@ -84,6 +86,16 @@ public void addResource(OCFResource resource)
     containerNeedsRebuild = true;
   }
 
+  public OCFZipResources getZipResources()
+  {
+    return zipResources;
+  }
+
+  public void setZipResources(OCFZipResources zipResources)
+  {
+    this.zipResources = zipResources;
+  }
+
   public void addRootfile(String mediaType, URL resource)
   {
     Preconditions.checkNotNull(mediaType);

src/main/java/com/adobe/epubcheck/ocf/OCFZipResources.java

@@ -103,6 +103,11 @@ public String toString()
     };
   }
 
+  public void close() throws IOException
+  {
+    zip.close();
+  }
+
   private static String getSHAHash(ZipEntry entry, ZipFile zip)
   {
     try (InputStream inputStream = zip.getInputStream(entry))