1 files changed, 40 insertions, 0 deletions
diff --git a/java/com/google/gerrit/server/events/SupplierDeserializer.java b/java/com/google/gerrit/server/events/SupplierDeserializer.java
new file mode 100644
index 0000000000..a6e27b8eb1
--- /dev/null
+++ b/java/com/google/gerrit/server/events/SupplierDeserializer.java
@@ -0,0 +1,40 @@
+// Copyright (C) 2016 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.google.gerrit.server.events;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.common.base.Supplier;
+import com.google.common.base.Suppliers;
+import com.google.gson.JsonDeserializationContext;
+import com.google.gson.JsonDeserializer;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonParseException;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+
+public class SupplierDeserializer implements JsonDeserializer<Supplier<?>> {
+
+  @Override
+  public Supplier<?> deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
+      throws JsonParseException {
+    checkArgument(typeOfT instanceof ParameterizedType);
+    ParameterizedType parameterizedType = (ParameterizedType) typeOfT;
+    if (parameterizedType.getActualTypeArguments().length != 1) {
+      throw new JsonParseException("Expected one parameter type in Supplier interface.");
+    }
+    Type supplierOf = parameterizedType.getActualTypeArguments()[0];
+    return Suppliers.ofInstance(context.deserialize(json, supplierOf));
+  }
+}