Line data    Source code

       1             : // Copyright (C) 2016 The Android Open Source Project
       2             : //
       3             : // Licensed under the Apache License, Version 2.0 (the "License");
       4             : // you may not use this file except in compliance with the License.
       5             : // You may obtain a copy of the License at
       6             : //
       7             : // http://www.apache.org/licenses/LICENSE-2.0
       8             : //
       9             : // Unless required by applicable law or agreed to in writing, software
      10             : // distributed under the License is distributed on an "AS IS" BASIS,
      11             : // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      12             : // See the License for the specific language governing permissions and
      13             : // limitations under the License.
      14             : package com.google.gerrit.server.events;
      15             : 
      16             : import static com.google.common.base.Preconditions.checkArgument;
      17             : 
      18             : import com.google.common.base.Supplier;
      19             : import com.google.common.base.Suppliers;
      20             : import com.google.gson.JsonDeserializationContext;
      21             : import com.google.gson.JsonDeserializer;
      22             : import com.google.gson.JsonElement;
      23             : import com.google.gson.JsonParseException;
      24             : import java.lang.reflect.ParameterizedType;
      25             : import java.lang.reflect.Type;
      26             : 
      27           2 : public class SupplierDeserializer implements JsonDeserializer<Supplier<?>> {
      28             : 
      29             :   @Override
      30             :   public Supplier<?> deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
      31             :       throws JsonParseException {
      32           1 :     checkArgument(typeOfT instanceof ParameterizedType);
      33           1 :     ParameterizedType parameterizedType = (ParameterizedType) typeOfT;
      34           1 :     if (parameterizedType.getActualTypeArguments().length != 1) {
      35           0 :       throw new JsonParseException("Expected one parameter type in Supplier interface.");
      36             :     }
      37           1 :     Type supplierOf = parameterizedType.getActualTypeArguments()[0];
      38           1 :     return Suppliers.ofInstance(context.deserialize(json, supplierOf));
      39             :   }
      40             : }