Add a provider for gson instances containing required type adapters to avoid code duplication when registering type adapters for the Gson instances used by the REST forwarder implementation to handle event processing in json format. Change-Id: Ibdcde4c63a4b0ff6b77e19068382b2fee8d3fa6c

diff --git a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/AbstractIndexRestApiServlet.java b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/AbstractIndexRestApiServlet.java
index 0c90ebe..108c37c 100644
--- a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/AbstractIndexRestApiServlet.java
+++ b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/AbstractIndexRestApiServlet.java

@@ -23,16 +23,13 @@
 import com.ericsson.gerrit.plugins.highavailability.forwarder.ForwardedIndexingHandler.Operation;
 import com.ericsson.gerrit.plugins.highavailability.forwarder.IndexEvent;
 import com.ericsson.gerrit.plugins.highavailability.forwarder.ProcessorMetricsRegistry;
-import com.ericsson.gerrit.plugins.highavailability.forwarder.jgroups.InstantTypeAdapter;
 import com.google.common.base.Charsets;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.extensions.restapi.NotImplementedException;
-import com.google.gerrit.server.events.EventGson;
 import com.google.gson.Gson;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.Reader;
-import java.time.Instant;
 import java.util.Optional;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
@@ -62,15 +59,14 @@
   AbstractIndexRestApiServlet(
       ForwardedIndexingHandler<T> forwardedIndexingHandler,
       IndexName indexName,
-      @EventGson Gson gson,
+      Gson gson,
       ProcessorMetricsRegistry metricsRegistry,
       EventType postEventType,
       @Nullable EventType deleteEventType) {
     super(metricsRegistry, postEventType, deleteEventType);
     this.forwardedIndexingHandler = forwardedIndexingHandler;
     this.indexName = indexName;
-    this.gson =
-        gson.newBuilder().registerTypeAdapter(Instant.class, new InstantTypeAdapter()).create();
+    this.gson = gson;
     this.allowDelete = deleteEventType != null;
   }
 

diff --git a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/CacheKeyJsonParser.java b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/CacheKeyJsonParser.java
index 4be3715..6202f48 100644
--- a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/CacheKeyJsonParser.java
+++ b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/CacheKeyJsonParser.java

@@ -15,7 +15,6 @@
 package com.ericsson.gerrit.plugins.highavailability.forwarder.rest;
 
 import com.ericsson.gerrit.plugins.highavailability.cache.Constants;
-import com.ericsson.gerrit.plugins.highavailability.forwarder.jgroups.InstantTypeAdapter;
 import com.google.common.base.CharMatcher;
 import com.google.common.base.Strings;
 import com.google.common.base.Supplier;
@@ -23,21 +22,18 @@
 import com.google.gerrit.entities.Account;
 import com.google.gerrit.entities.AccountGroup;
 import com.google.gerrit.entities.Project;
-import com.google.gerrit.server.events.EventGson;
 import com.google.gson.Gson;
 import com.google.gson.JsonElement;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
-import java.time.Instant;
 
 @Singleton
 public class CacheKeyJsonParser {
   private final Gson gson;
 
   @Inject
-  public CacheKeyJsonParser(@EventGson Gson gson) {
-    this.gson =
-        gson.newBuilder().registerTypeAdapter(Instant.class, new InstantTypeAdapter()).create();
+  public CacheKeyJsonParser(@RestGson Gson gson) {
+    this.gson = gson;
   }
 
   public Object fromJson(String cacheName, String jsonString) {

diff --git a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/EventRestApiServlet.java b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/EventRestApiServlet.java
index 97a7179..422e3df 100644
--- a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/EventRestApiServlet.java
+++ b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/EventRestApiServlet.java

@@ -22,16 +22,13 @@
 import com.ericsson.gerrit.plugins.highavailability.forwarder.EventType;
 import com.ericsson.gerrit.plugins.highavailability.forwarder.ForwardedEventHandler;
 import com.ericsson.gerrit.plugins.highavailability.forwarder.ProcessorMetricsRegistry;
-import com.ericsson.gerrit.plugins.highavailability.forwarder.jgroups.InstantTypeAdapter;
 import com.google.common.io.CharStreams;
 import com.google.common.net.MediaType;
 import com.google.gerrit.server.events.Event;
-import com.google.gerrit.server.events.EventGson;
 import com.google.gson.Gson;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 import java.io.IOException;
-import java.time.Instant;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
@@ -45,12 +42,11 @@
   @Inject
   EventRestApiServlet(
       ForwardedEventHandler forwardedEventHandler,
-      @EventGson Gson gson,
+      @RestGson Gson gson,
       ProcessorMetricsRegistry metricRegistry) {
     super(metricRegistry, EventType.EVENT_SENT, null);
     this.forwardedEventHandler = forwardedEventHandler;
-    this.gson =
-        gson.newBuilder().registerTypeAdapter(Instant.class, new InstantTypeAdapter()).create();
+    this.gson = gson;
   }
 
   @Override

diff --git a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexAccountRestApiServlet.java b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexAccountRestApiServlet.java
index 047da64..1adfbbe 100644
--- a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexAccountRestApiServlet.java
+++ b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexAccountRestApiServlet.java

@@ -18,7 +18,6 @@
 import com.ericsson.gerrit.plugins.highavailability.forwarder.ForwardedIndexAccountHandler;
 import com.ericsson.gerrit.plugins.highavailability.forwarder.ProcessorMetricsRegistry;
 import com.google.gerrit.entities.Account;
-import com.google.gerrit.server.events.EventGson;
 import com.google.gson.Gson;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
@@ -30,7 +29,7 @@
   @Inject
   IndexAccountRestApiServlet(
       ForwardedIndexAccountHandler handler,
-      @EventGson Gson gson,
+      @RestGson Gson gson,
       ProcessorMetricsRegistry metricRegistry) {
     super(handler, IndexName.ACCOUNT, gson, metricRegistry, EventType.INDEX_ACCOUNT_UPDATE, null);
   }

diff --git a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexBatchChangeRestApiServlet.java b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexBatchChangeRestApiServlet.java
index 5816cb5..7c593be 100644
--- a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexBatchChangeRestApiServlet.java
+++ b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexBatchChangeRestApiServlet.java

@@ -18,7 +18,6 @@
 import com.ericsson.gerrit.plugins.highavailability.forwarder.ForwardedIndexBatchChangeHandler;
 import com.ericsson.gerrit.plugins.highavailability.forwarder.ProcessorMetricsRegistry;
 import com.google.gerrit.extensions.restapi.Url;
-import com.google.gerrit.server.events.EventGson;
 import com.google.gson.Gson;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
@@ -30,7 +29,7 @@
   @Inject
   IndexBatchChangeRestApiServlet(
       ForwardedIndexBatchChangeHandler handler,
-      @EventGson Gson gson,
+      @RestGson Gson gson,
       ProcessorMetricsRegistry metricRegistry) {
     super(
         handler, IndexName.CHANGE, gson, metricRegistry, EventType.INDEX_CHANGE_UPDATE_BATCH, null);

diff --git a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexChangeRestApiServlet.java b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexChangeRestApiServlet.java
index 4d8d9a3..f63ceeb 100644
--- a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexChangeRestApiServlet.java
+++ b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexChangeRestApiServlet.java

@@ -18,7 +18,6 @@
 import com.ericsson.gerrit.plugins.highavailability.forwarder.ForwardedIndexChangeHandler;
 import com.ericsson.gerrit.plugins.highavailability.forwarder.ProcessorMetricsRegistry;
 import com.google.gerrit.extensions.restapi.Url;
-import com.google.gerrit.server.events.EventGson;
 import com.google.gson.Gson;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
@@ -30,7 +29,7 @@
   @Inject
   IndexChangeRestApiServlet(
       ForwardedIndexChangeHandler handler,
-      @EventGson Gson gson,
+      @RestGson Gson gson,
       ProcessorMetricsRegistry metricRegistry) {
     super(
         handler,

diff --git a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexGroupRestApiServlet.java b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexGroupRestApiServlet.java
index ed9b57e..6328cd7 100644
--- a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexGroupRestApiServlet.java
+++ b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexGroupRestApiServlet.java

@@ -18,7 +18,6 @@
 import com.ericsson.gerrit.plugins.highavailability.forwarder.ForwardedIndexGroupHandler;
 import com.ericsson.gerrit.plugins.highavailability.forwarder.ProcessorMetricsRegistry;
 import com.google.gerrit.entities.AccountGroup;
-import com.google.gerrit.server.events.EventGson;
 import com.google.gson.Gson;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
@@ -30,7 +29,7 @@
   @Inject
   IndexGroupRestApiServlet(
       ForwardedIndexGroupHandler handler,
-      @EventGson Gson gson,
+      @RestGson Gson gson,
       ProcessorMetricsRegistry metricRegistry) {
     super(handler, IndexName.GROUP, gson, metricRegistry, EventType.INDEX_GROUP_UPDATE, null);
   }

diff --git a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexProjectRestApiServlet.java b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexProjectRestApiServlet.java
index fbf7ffd..bf3a3f0 100644
--- a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexProjectRestApiServlet.java
+++ b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/IndexProjectRestApiServlet.java

@@ -19,7 +19,6 @@
 import com.ericsson.gerrit.plugins.highavailability.forwarder.ProcessorMetricsRegistry;
 import com.google.gerrit.entities.Project;
 import com.google.gerrit.extensions.restapi.Url;
-import com.google.gerrit.server.events.EventGson;
 import com.google.gson.Gson;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
@@ -31,7 +30,7 @@
   @Inject
   IndexProjectRestApiServlet(
       ForwardedIndexProjectHandler handler,
-      @EventGson Gson gson,
+      @RestGson Gson gson,
       ProcessorMetricsRegistry metricRegistry) {
     super(handler, IndexName.PROJECT, gson, metricRegistry, EventType.INDEX_PROJECT_UPDATE, null);
   }

diff --git a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/RestForwarderModule.java b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/RestForwarderModule.java
index 5d38b16..829efad 100644
--- a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/RestForwarderModule.java
+++ b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/RestForwarderModule.java

@@ -16,10 +16,16 @@
 
 import com.ericsson.gerrit.plugins.highavailability.forwarder.Forwarder;
 import com.ericsson.gerrit.plugins.highavailability.forwarder.Forwarder.Result;
+import com.ericsson.gerrit.plugins.highavailability.forwarder.jgroups.InstantTypeAdapter;
+import com.google.gerrit.server.events.EventGson;
+import com.google.gson.Gson;
 import com.google.inject.AbstractModule;
+import com.google.inject.Provides;
 import com.google.inject.Scopes;
+import com.google.inject.Singleton;
 import com.google.inject.TypeLiteral;
 import dev.failsafe.FailsafeExecutor;
+import java.time.Instant;
 import org.apache.http.impl.client.CloseableHttpClient;
 
 public class RestForwarderModule extends AbstractModule {
@@ -35,4 +41,14 @@
         .toProvider(FailsafeExecutorProvider.class)
         .in(Scopes.SINGLETON);
   }
+
+  @Provides
+  @Singleton
+  @RestGson
+  Gson buildRestGson(@EventGson Gson eventGson) {
+    return eventGson
+        .newBuilder()
+        .registerTypeAdapter(Instant.class, new InstantTypeAdapter())
+        .create();
+  }
 }

diff --git a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/RestGson.java b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/RestGson.java
new file mode 100644
index 0000000..e55ddd9
--- /dev/null
+++ b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/RestGson.java

@@ -0,0 +1,24 @@
+// Copyright (C) 2026 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.ericsson.gerrit.plugins.highavailability.forwarder.rest;
+
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import com.google.inject.BindingAnnotation;
+import java.lang.annotation.Retention;
+
+@BindingAnnotation
+@Retention(RUNTIME)
+public @interface RestGson {}