Paul Duffin | e236301 | 2015-11-30 16:20:41 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2012 Google Inc. |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package com.google.caliper.json; |
| 18 | |
| 19 | import com.google.common.collect.ImmutableList; |
| 20 | import com.google.common.collect.Lists; |
| 21 | import com.google.gson.Gson; |
| 22 | import com.google.gson.TypeAdapter; |
| 23 | import com.google.gson.TypeAdapterFactory; |
| 24 | import com.google.gson.reflect.TypeToken; |
| 25 | import com.google.gson.stream.JsonReader; |
| 26 | import com.google.gson.stream.JsonWriter; |
| 27 | |
| 28 | import java.io.IOException; |
| 29 | import java.lang.reflect.ParameterizedType; |
| 30 | import java.lang.reflect.Type; |
| 31 | import java.util.ArrayList; |
| 32 | import java.util.List; |
| 33 | |
| 34 | /** |
| 35 | * Serializes and deserializes {@link ImmutableList} instances using an {@link ArrayList} as an |
| 36 | * intermediary. |
| 37 | */ |
| 38 | final class ImmutableListTypeAdatperFactory implements TypeAdapterFactory { |
| 39 | @SuppressWarnings("unchecked") |
| 40 | @Override public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) { |
| 41 | Type type = typeToken.getType(); |
| 42 | if (typeToken.getRawType() != ImmutableList.class |
| 43 | || !(type instanceof ParameterizedType)) { |
| 44 | return null; |
| 45 | } |
| 46 | |
| 47 | com.google.common.reflect.TypeToken<ImmutableList<?>> betterToken = |
| 48 | (com.google.common.reflect.TypeToken<ImmutableList<?>>) |
| 49 | com.google.common.reflect.TypeToken.of(typeToken.getType()); |
| 50 | final TypeAdapter<ArrayList<?>> arrayListAdapter = |
| 51 | (TypeAdapter<ArrayList<?>>) gson.getAdapter( |
| 52 | TypeToken.get(betterToken.getSupertype(List.class).getSubtype(ArrayList.class) |
| 53 | .getType())); |
| 54 | return new TypeAdapter<T>() { |
| 55 | @Override public void write(JsonWriter out, T value) throws IOException { |
| 56 | ArrayList<?> arrayList = Lists.newArrayList((List<?>) value); |
| 57 | arrayListAdapter.write(out, arrayList); |
| 58 | } |
| 59 | |
| 60 | @Override public T read(JsonReader in) throws IOException { |
| 61 | ArrayList<?> arrayList = arrayListAdapter.read(in); |
| 62 | return (T) ImmutableList.copyOf(arrayList); |
| 63 | } |
| 64 | }; |
| 65 | } |
| 66 | } |