/* * Copyright (C) 2009 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.functional; import com.google.gson.Gson; import com.google.gson.GsonBuilder; import com.google.gson.InstanceCreator; import com.google.gson.common.TestTypes.Base; import com.google.gson.common.TestTypes.ClassWithBaseField; import com.google.gson.common.TestTypes.Sub; import com.google.gson.reflect.TypeToken; import java.util.ArrayList; import java.util.List; import junit.framework.TestCase; import java.lang.reflect.Type; import java.util.SortedSet; import java.util.TreeSet; /** * Functional Test exercising custom serialization only. When test applies to both * serialization and deserialization then add it to CustomTypeAdapterTest. * * @author Inderjeet Singh */ public class InstanceCreatorTest extends TestCase { public void testInstanceCreatorReturnsBaseType() { Gson gson = new GsonBuilder() .registerTypeAdapter(Base.class, new InstanceCreator() { @Override public Base createInstance(Type type) { return new Base(); } }) .create(); String json = "{baseName:'BaseRevised',subName:'Sub'}"; Base base = gson.fromJson(json, Base.class); assertEquals("BaseRevised", base.baseName); } public void testInstanceCreatorReturnsSubTypeForTopLevelObject() { Gson gson = new GsonBuilder() .registerTypeAdapter(Base.class, new InstanceCreator() { @Override public Base createInstance(Type type) { return new Sub(); } }) .create(); String json = "{baseName:'Base',subName:'SubRevised'}"; Base base = gson.fromJson(json, Base.class); assertTrue(base instanceof Sub); Sub sub = (Sub) base; assertFalse("SubRevised".equals(sub.subName)); assertEquals(Sub.SUB_NAME, sub.subName); } public void testInstanceCreatorReturnsSubTypeForField() { Gson gson = new GsonBuilder() .registerTypeAdapter(Base.class, new InstanceCreator() { @Override public Base createInstance(Type type) { return new Sub(); } }) .create(); String json = "{base:{baseName:'Base',subName:'SubRevised'}}"; ClassWithBaseField target = gson.fromJson(json, ClassWithBaseField.class); assertTrue(target.base instanceof Sub); assertEquals(Sub.SUB_NAME, ((Sub)target.base).subName); } // This regressed in Gson 2.0 and 2.1 public void testInstanceCreatorForCollectionType() { @SuppressWarnings("serial") class SubArrayList extends ArrayList {} InstanceCreator> listCreator = new InstanceCreator>() { @Override public List createInstance(Type type) { return new SubArrayList<>(); } }; Type listOfStringType = new TypeToken>() {}.getType(); Gson gson = new GsonBuilder() .registerTypeAdapter(listOfStringType, listCreator) .create(); List list = gson.fromJson("[\"a\"]", listOfStringType); assertEquals(SubArrayList.class, list.getClass()); } @SuppressWarnings({ "unchecked", "rawtypes" }) public void testInstanceCreatorForParametrizedType() throws Exception { @SuppressWarnings("serial") class SubTreeSet extends TreeSet {} InstanceCreator sortedSetCreator = new InstanceCreator() { @Override public SortedSet createInstance(Type type) { return new SubTreeSet(); } }; Gson gson = new GsonBuilder() .registerTypeAdapter(SortedSet.class, sortedSetCreator) .create(); Type sortedSetType = new TypeToken>() {}.getType(); SortedSet set = gson.fromJson("[\"a\"]", sortedSetType); assertEquals(set.first(), "a"); assertEquals(SubTreeSet.class, set.getClass()); set = gson.fromJson("[\"b\"]", SortedSet.class); assertEquals(set.first(), "b"); assertEquals(SubTreeSet.class, set.getClass()); } }