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 } 67
