/*
* Copyright (C) 2014 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.annotations.JsonAdapter;
import com.google.gson.internal.ConstructorConstructor;
import com.google.gson.internal.ObjectConstructor;
import com.google.gson.reflect.TypeToken;
/**
* Given a type T, looks for the annotation {@link JsonAdapter} and uses an instance of the
* specified class as the default type adapter.
*
* @since 2.3
*/
public final class JsonAdapterAnnotationTypeAdapterFactory implements TypeAdapterFactory {
private final ConstructorConstructor constructorConstructor;
public JsonAdapterAnnotationTypeAdapterFactory(ConstructorConstructor constructorConstructor) {
this.constructorConstructor = constructorConstructor;
}
@SuppressWarnings({ "rawtypes", "unchecked" })
public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> targetType) {
Class<? super T> clazz = targetType.getRawType();
JsonAdapter annotation = clazz.getAnnotation(JsonAdapter.class);
if (annotation == null) return null;
TypeAdapter adapter = getAnnotationTypeAdapter(gson, constructorConstructor, annotation);
return adapter;
}
static TypeAdapter<?> getAnnotationTypeAdapter(Gson gson,
ConstructorConstructor constructorConstructor, JsonAdapter annotation) {
Class<? extends TypeAdapter<?>> adapterClass = annotation.value();
ObjectConstructor<? extends TypeAdapter<?>> constructor =
constructorConstructor.get(TypeToken.get(adapterClass));
TypeAdapter<?> adapter = constructor.construct();
Gson.$$Internal.addGeneratedTypeAdapter(gson, adapter);
return adapter;
}
}