| /* |
| * Copyright (C) 2011 Google Inc. |
| * |
| * 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.gson.internal.bind; |
| |
| import com.google.gson.Gson; |
| import com.google.gson.TypeAdapter; |
| import com.google.gson.TypeAdapterFactory; |
| import com.google.gson.internal.$Gson$Types; |
| import com.google.gson.internal.ConstructorConstructor; |
| import com.google.gson.internal.ObjectConstructor; |
| import com.google.gson.reflect.TypeToken; |
| import com.google.gson.stream.JsonReader; |
| import com.google.gson.stream.JsonToken; |
| import com.google.gson.stream.JsonWriter; |
| import java.io.IOException; |
| import java.lang.reflect.Type; |
| import java.util.Collection; |
| |
| /** |
| * Adapt a homogeneous collection of objects. |
| */ |
| public final class CollectionTypeAdapterFactory implements TypeAdapterFactory { |
| private final ConstructorConstructor constructorConstructor; |
| |
| public CollectionTypeAdapterFactory(ConstructorConstructor constructorConstructor) { |
| this.constructorConstructor = constructorConstructor; |
| } |
| |
| @Override |
| public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) { |
| Type type = typeToken.getType(); |
| |
| Class<? super T> rawType = typeToken.getRawType(); |
| if (!Collection.class.isAssignableFrom(rawType)) { |
| return null; |
| } |
| |
| Type elementType = $Gson$Types.getCollectionElementType(type, rawType); |
| TypeAdapter<?> elementTypeAdapter = gson.getAdapter(TypeToken.get(elementType)); |
| ObjectConstructor<T> constructor = constructorConstructor.get(typeToken); |
| |
| @SuppressWarnings({"unchecked", "rawtypes"}) // create() doesn't define a type parameter |
| TypeAdapter<T> result = new Adapter(gson, elementType, elementTypeAdapter, constructor); |
| return result; |
| } |
| |
| private static final class Adapter<E> extends TypeAdapter<Collection<E>> { |
| private final TypeAdapter<E> elementTypeAdapter; |
| private final ObjectConstructor<? extends Collection<E>> constructor; |
| |
| public Adapter(Gson context, Type elementType, |
| TypeAdapter<E> elementTypeAdapter, |
| ObjectConstructor<? extends Collection<E>> constructor) { |
| this.elementTypeAdapter = |
| new TypeAdapterRuntimeTypeWrapper<E>(context, elementTypeAdapter, elementType); |
| this.constructor = constructor; |
| } |
| |
| @Override public Collection<E> read(JsonReader in) throws IOException { |
| if (in.peek() == JsonToken.NULL) { |
| in.nextNull(); |
| return null; |
| } |
| |
| Collection<E> collection = constructor.construct(); |
| in.beginArray(); |
| while (in.hasNext()) { |
| E instance = elementTypeAdapter.read(in); |
| collection.add(instance); |
| } |
| in.endArray(); |
| return collection; |
| } |
| |
| @Override public void write(JsonWriter out, Collection<E> collection) throws IOException { |
| if (collection == null) { |
| out.nullValue(); |
| return; |
| } |
| |
| out.beginArray(); |
| for (E element : collection) { |
| elementTypeAdapter.write(out, element); |
| } |
| out.endArray(); |
| } |
| } |
| } |