Index: trunk/src/com/drew/metadata/Metadata.java
===================================================================
--- trunk/src/com/drew/metadata/Metadata.java	(revision 8243)
+++ trunk/src/com/drew/metadata/Metadata.java	(revision 10862)
@@ -1,4 +1,4 @@
 /*
- * Copyright 2002-2015 Drew Noakes
+ * Copyright 2002-2016 Drew Noakes
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
@@ -36,6 +36,9 @@
 public final class Metadata
 {
+    /**
+     * The list of {@link Directory} instances in this container, in the order they were added.
+     */
     @NotNull
-    private final Map<Class<? extends Directory>,Collection<Directory>> _directoryListByClass = new HashMap<Class<? extends Directory>, Collection<Directory>>();
+    private final List<Directory> _directories = new ArrayList<>();
 
     /**
@@ -47,11 +50,18 @@
     public Iterable<Directory> getDirectories()
     {
-        return new DirectoryIterable(_directoryListByClass);
+        return _directories;
     }
 
     @Nullable
+    @SuppressWarnings("unchecked")
     public <T extends Directory> Collection<T> getDirectoriesOfType(Class<T> type)
     {
-        return (Collection<T>)_directoryListByClass.get(type);
+        List<T> directories = new ArrayList<>();
+        for (Directory dir : _directories) {
+            if (type.isAssignableFrom(dir.getClass())) {
+                directories.add((T)dir);
+            }
+        }
+        return directories;
     }
 
@@ -63,8 +73,5 @@
     public int getDirectoryCount()
     {
-        int count = 0;
-        for (Map.Entry<Class<? extends Directory>,Collection<Directory>> pair : _directoryListByClass.entrySet())
-            count += pair.getValue().size();
-        return count;
+        return _directories.size();
     }
 
@@ -76,5 +83,5 @@
     public <T extends Directory> void addDirectory(@NotNull T directory)
     {
-        getOrCreateDirectoryList(directory.getClass()).add(directory);
+        _directories.add(directory);
     }
 
@@ -91,13 +98,9 @@
     public <T extends Directory> T getFirstDirectoryOfType(@NotNull Class<T> type)
     {
-        // We suppress the warning here as the code asserts a map signature of Class<T>,T.
-        // So after get(Class<T>) it is for sure the result is from type T.
-
-        Collection<Directory> list = getDirectoryList(type);
-
-        if (list == null || list.isEmpty())
-            return null;
-
-        return (T)list.iterator().next();
+        for (Directory dir : _directories) {
+            if (type.isAssignableFrom(dir.getClass()))
+                return (T)dir;
+        }
+        return null;
     }
 
@@ -110,6 +113,9 @@
     public boolean containsDirectoryOfType(Class<? extends Directory> type)
     {
-        Collection<Directory> list = getDirectoryList(type);
-        return list != null && !list.isEmpty();
+        for (Directory dir : _directories) {
+            if (type.isAssignableFrom(dir.getClass()))
+                return true;
+        }
+        return false;
     }
 
@@ -139,72 +145,3 @@
                 : "directories");
     }
-
-    @Nullable
-    private <T extends Directory> Collection<Directory> getDirectoryList(@NotNull Class<T> type)
-    {
-        return _directoryListByClass.get(type);
-    }
-
-    @NotNull
-    private <T extends Directory> Collection<Directory> getOrCreateDirectoryList(@NotNull Class<T> type)
-    {
-        Collection<Directory> collection = getDirectoryList(type);
-        if (collection != null)
-            return collection;
-        collection = new ArrayList<Directory>();
-        _directoryListByClass.put(type, collection);
-        return collection;
-    }
-
-    private static class DirectoryIterable implements Iterable<Directory>
-    {
-        private final Map<Class<? extends Directory>, Collection<Directory>> _map;
-
-        public DirectoryIterable(Map<Class<? extends Directory>, Collection<Directory>> map)
-        {
-            _map = map;
-        }
-
-        public Iterator<Directory> iterator()
-        {
-            return new DirectoryIterator(_map);
-        }
-
-        private static class DirectoryIterator implements Iterator<Directory>
-        {
-            @NotNull
-            private final Iterator<Map.Entry<Class<? extends Directory>, Collection<Directory>>> _mapIterator;
-            @Nullable
-            private Iterator<Directory> _listIterator;
-
-            public DirectoryIterator(Map<Class<? extends Directory>, Collection<Directory>> map)
-            {
-                _mapIterator = map.entrySet().iterator();
-
-                if (_mapIterator.hasNext())
-                    _listIterator = _mapIterator.next().getValue().iterator();
-            }
-
-            public boolean hasNext()
-            {
-                return _listIterator != null && (_listIterator.hasNext() || _mapIterator.hasNext());
-            }
-
-            public Directory next()
-            {
-                if (_listIterator == null || (!_listIterator.hasNext() && !_mapIterator.hasNext()))
-                    throw new NoSuchElementException();
-
-                while (!_listIterator.hasNext())
-                    _listIterator = _mapIterator.next().getValue().iterator();
-
-                return _listIterator.next();
-            }
-
-            public void remove()
-            {
-                throw new UnsupportedOperationException();
-            }
-        }
-    }
 }