Java tutorial
package TestGenerator.ArgumentCache; /** * Created by NatchaS on 10/8/16. */ /* * 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. */ import com.google.gson.Gson; import com.google.gson.JsonArray; import com.google.gson.JsonElement; import com.google.gson.JsonObject; import com.google.gson.JsonPrimitive; 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.Array; import java.lang.reflect.Field; import java.lang.reflect.Type; import java.util.Collection; /** * Adapt a homogeneous collection of objects. */ public final class UniversalCollectionTypeAdapterFactory implements TypeAdapterFactory { private ConstructorConstructor constructorConstructor; public UniversalCollectionTypeAdapterFactory(ConstructorConstructor constructorConstructor) { this.constructorConstructor = constructorConstructor; } public UniversalCollectionTypeAdapterFactory() { } @Override public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) { Type type = typeToken.getType(); /// hack to obtain hidden constructorConstructor from gson - guarantees that gson has already initialized // and the original CollectionTypeAdapterFactory has been assigned the same constructorConstructor. if (constructorConstructor == null) { try { Field conf = gson.getClass().getDeclaredField("constructorConstructor"); conf.setAccessible(true); constructorConstructor = (ConstructorConstructor) conf.get(gson); } catch (NoSuchFieldException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } } 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 TypeAdapter<E> elementTypeAdapter; private final ObjectConstructor<? extends Collection<E>> constructor; private TypeAdapter<JsonElement> jsonElementTypeAdapter; private final Gson gson; public Adapter(Gson context, Type elementType, TypeAdapter<E> elementTypeAdapter, ObjectConstructor<? extends Collection<E>> constructor) { this.elementTypeAdapter = new UniversalTypeAdapterRuntimeTypeWrapper<E>(context, elementTypeAdapter, elementType); this.constructor = constructor; this.jsonElementTypeAdapter = context.getAdapter(JsonElement.class); this.gson = context; } @Override public void write(JsonWriter out, Collection<E> collection) throws IOException { out.setLenient(true); if (collection == null) { out.nullValue(); return; } JsonObject jsonArrayWrapper = new JsonObject(); JsonArray jsonArray = new JsonArray(); JsonArray jsonArrayType = new JsonArray(); for (E element : collection) { JsonElement jsonElement = elementTypeAdapter.toJsonTree(element); jsonArray.add(jsonElement); jsonArrayType.add(jsonElement.isJsonNull() ? null : element.getClass().getName()); } jsonArrayWrapper.add(UniversalTypeAdapterFactory.array_token, jsonArray); jsonArrayWrapper.add(UniversalTypeAdapterFactory.array_type, jsonArrayType); jsonArrayWrapper.add(UniversalTypeAdapterFactory.class_token, new JsonPrimitive(collection.getClass().getName())); jsonElementTypeAdapter.write(out, jsonArrayWrapper); /* // ORIGINAL CODE out.beginArray(); for (E element : collection) { elementTypeAdapter.write(out, element); } out.endArray(); */ } @Override public Collection<E> read(JsonReader in) throws IOException { if (in.peek() == JsonToken.NULL) { in.nextNull(); return null; } JsonElement jsonElement = jsonElementTypeAdapter.read(in); Collection<E> collection = constructor.construct(); if (jsonElement.isJsonObject()) { JsonObject collectionWrapper = jsonElement.getAsJsonObject(); JsonArray elementArray = collectionWrapper.get(UniversalTypeAdapterFactory.array_token) .getAsJsonArray(); JsonArray elementArrayType = collectionWrapper.get(UniversalTypeAdapterFactory.array_type) .getAsJsonArray(); for (int i = 0; i < elementArray.size(); i++) { try { E o = null; if (!elementArray.get(i).isJsonNull()) { Class elementType = Class.forName(elementArrayType.get(i).getAsString()); o = (E) gson.fromJson(elementArray.get(i), Class.forName(elementArrayType.get(i).getAsString())); } collection.add(o); } catch (ClassNotFoundException e) { e.printStackTrace(); } } } else { throw new IllegalStateException("[UniversalCollectionTypeAdapter] cannot deserialize " + jsonElement.getClass().getSimpleName() + " \n" + jsonElement); } /* // ORIGINAL CODE Collection<E> collection = constructor.construct(); in.beginArray(); while (in.hasNext()) { E instance = elementTypeAdapter.read(in); collection.add(instance); } in.endArray(); */ return collection; } } }