From 970b6e357949e7a23ab09fedfc491ea63bed096a Mon Sep 17 00:00:00 2001
From: Michael Innerberger <innerbergerm@hhmi.org>
Date: Thu, 19 Oct 2023 17:49:46 -0400
Subject: [PATCH] Make Filter an interface again

---
 .../janelia/saalfeldlab/n5/zarr/Filter.java   | 34 +++++++++----------
 .../n5/zarr/ZarrKeyValueReader.java           |  3 +-
 2 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/src/main/java/org/janelia/saalfeldlab/n5/zarr/Filter.java b/src/main/java/org/janelia/saalfeldlab/n5/zarr/Filter.java
index 988f243..3c756b2 100644
--- a/src/main/java/org/janelia/saalfeldlab/n5/zarr/Filter.java
+++ b/src/main/java/org/janelia/saalfeldlab/n5/zarr/Filter.java
@@ -47,31 +47,31 @@
  * @author Stephan Saalfeld &lt;saalfelds@janelia.hhmi.org&gt;
  * @author Michael Innerberger
  */
-public enum Filter {
-    // Note: the JSON (de-)serializer below is very much tailored to this filter, which serializes to "{"id":"vlen-utf8"}"
-    // If additional filters are implemented, consider also changing the type adapter below
-    VLEN_UTF8("vlen-utf8");
+public interface Filter {
 
-    private final String id;
+    String getId();
 
-    Filter(final String id) {
-        this.id = id;
-    }
+    // Note: the JSON (de-)serializer below is very much tailored to this filter, which serializes to "{"id":"vlen-utf8"}"
+    // If additional filters are implemented, consider also changing the type adapter below
+    Filter VLEN_UTF8 = new VLenStringFilter();
 
-    public String getId() {
-        return id;
-    }
+    class VLenStringFilter implements Filter {
+        private static final String id = "vlen-utf8";
+        @Override
+        public String getId() {
+            return id;
+        }
+    };
 
-    public static Filter fromString(final String id) {
-        for (final Filter filter : values())
-            if (filter.getId().equals(id))
-                return filter;
+    static Filter fromString(final String id) {
+        if (VLEN_UTF8.getId().equals(id))
+                return VLEN_UTF8;
         return null;
     }
 
-    public static final JsonAdapter jsonAdapter = new JsonAdapter();
+    JsonAdapter jsonAdapter = new JsonAdapter();
 
-    public static class JsonAdapter implements JsonDeserializer<Filter>, JsonSerializer<Filter> {
+    class JsonAdapter implements JsonDeserializer<Filter>, JsonSerializer<Filter> {
 
         @Override
         public Filter deserialize(
diff --git a/src/main/java/org/janelia/saalfeldlab/n5/zarr/ZarrKeyValueReader.java b/src/main/java/org/janelia/saalfeldlab/n5/zarr/ZarrKeyValueReader.java
index 9ca58a2..c059b69 100644
--- a/src/main/java/org/janelia/saalfeldlab/n5/zarr/ZarrKeyValueReader.java
+++ b/src/main/java/org/janelia/saalfeldlab/n5/zarr/ZarrKeyValueReader.java
@@ -35,7 +35,6 @@
 import java.net.URISyntaxException;
 import java.nio.ByteBuffer;
 import java.util.Arrays;
-import java.util.Collection;
 
 import org.apache.commons.compress.utils.IOUtils;
 import org.janelia.saalfeldlab.n5.BlockReader;
@@ -841,7 +840,7 @@ protected static GsonBuilder addTypeAdapters(final GsonBuilder gsonBuilder) {
 		gsonBuilder.registerTypeHierarchyAdapter(Compression.class, CompressionAdapter.getJsonAdapter());
 		gsonBuilder.registerTypeAdapter(Compression.class, CompressionAdapter.getJsonAdapter());
 		gsonBuilder.registerTypeAdapter(ZArrayAttributes.class, ZArrayAttributes.jsonAdapter);
-		gsonBuilder.registerTypeAdapter(Filter.class, Filter.jsonAdapter);
+		gsonBuilder.registerTypeHierarchyAdapter(Filter.class, Filter.jsonAdapter);
 		gsonBuilder.disableHtmlEscaping();
 		gsonBuilder.serializeNulls();