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/*
* 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.functional;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParseException;
import com.google.gson.JsonPrimitive;
import com.google.gson.JsonSerializationContext;
import com.google.gson.JsonSerializer;
import java.lang.reflect.Type;
import junit.framework.TestCase;
/**
* Test that the hierarchy adapter works when subtypes are used.
*/
public final class TypeHierarchyAdapterTest extends TestCase {
public void testTypeHierarchy() {
Manager andy = new Manager();
andy.userid = "andy";
andy.startDate = 2005;
andy.minions = new Employee[] {
new Employee("inder", 2007),
new Employee("joel", 2006),
new Employee("jesse", 2006),
};
CEO eric = new CEO();
eric.userid = "eric";
eric.startDate = 2001;
eric.assistant = new Employee("jerome", 2006);
eric.minions = new Employee[] {
new Employee("larry", 1998),
new Employee("sergey", 1998),
andy,
};
Gson gson = new GsonBuilder()
.registerTypeHierarchyAdapter(Employee.class, new EmployeeAdapter())
.setPrettyPrinting()
.create();
Company company = new Company();
company.ceo = eric;
String json = gson.toJson(company, Company.class);
assertEquals("{\n" +
" \"ceo\": {\n" +
" \"userid\": \"eric\",\n" +
" \"startDate\": 2001,\n" +
" \"minions\": [\n" +
" {\n" +
" \"userid\": \"larry\",\n" +
" \"startDate\": 1998\n" +
" },\n" +
" {\n" +
" \"userid\": \"sergey\",\n" +
" \"startDate\": 1998\n" +
" },\n" +
" {\n" +
" \"userid\": \"andy\",\n" +
" \"startDate\": 2005,\n" +
" \"minions\": [\n" +
" {\n" +
" \"userid\": \"inder\",\n" +
" \"startDate\": 2007\n" +
" },\n" +
" {\n" +
" \"userid\": \"joel\",\n" +
" \"startDate\": 2006\n" +
" },\n" +
" {\n" +
" \"userid\": \"jesse\",\n" +
" \"startDate\": 2006\n" +
" }\n" +
" ]\n" +
" }\n" +
" ],\n" +
" \"assistant\": {\n" +
" \"userid\": \"jerome\",\n" +
" \"startDate\": 2006\n" +
" }\n" +
" }\n" +
"}", json);
Company copied = gson.fromJson(json, Company.class);
assertEquals(json, gson.toJson(copied, Company.class));
assertEquals(copied.ceo.userid, company.ceo.userid);
assertEquals(copied.ceo.assistant.userid, company.ceo.assistant.userid);
assertEquals(copied.ceo.minions[0].userid, company.ceo.minions[0].userid);
assertEquals(copied.ceo.minions[1].userid, company.ceo.minions[1].userid);
assertEquals(copied.ceo.minions[2].userid, company.ceo.minions[2].userid);
assertEquals(((Manager) copied.ceo.minions[2]).minions[0].userid,
((Manager) company.ceo.minions[2]).minions[0].userid);
assertEquals(((Manager) copied.ceo.minions[2]).minions[1].userid,
((Manager) company.ceo.minions[2]).minions[1].userid);
}
public void testRegisterSuperTypeFirst() {
Gson gson = new GsonBuilder()
.registerTypeHierarchyAdapter(Employee.class, new EmployeeAdapter())
.registerTypeHierarchyAdapter(Manager.class, new ManagerAdapter())
.create();
Manager manager = new Manager();
manager.userid = "inder";
String json = gson.toJson(manager, Manager.class);
assertEquals("\"inder\"", json);
Manager copied = gson.fromJson(json, Manager.class);
assertEquals(manager.userid, copied.userid);
}
/** This behaviour changed in Gson 2.1; it used to throw. */
public void testRegisterSubTypeFirstAllowed() {
new GsonBuilder()
.registerTypeHierarchyAdapter(Manager.class, new ManagerAdapter())
.registerTypeHierarchyAdapter(Employee.class, new EmployeeAdapter())
.create();
}
static class ManagerAdapter implements JsonSerializer<Manager>, JsonDeserializer<Manager> {
@Override public Manager deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) {
Manager result = new Manager();
result.userid = json.getAsString();
return result;
}
@Override public JsonElement serialize(Manager src, Type typeOfSrc, JsonSerializationContext context) {
return new JsonPrimitive(src.userid);
}
}
static class EmployeeAdapter implements JsonSerializer<Employee>, JsonDeserializer<Employee> {
@Override public JsonElement serialize(Employee employee, Type typeOfSrc,
JsonSerializationContext context) {
JsonObject result = new JsonObject();
result.add("userid", context.serialize(employee.userid, String.class));
result.add("startDate", context.serialize(employee.startDate, long.class));
if (employee instanceof Manager) {
result.add("minions", context.serialize(((Manager) employee).minions, Employee[].class));
if (employee instanceof CEO) {
result.add("assistant", context.serialize(((CEO) employee).assistant, Employee.class));
}
}
return result;
}
@Override public Employee deserialize(JsonElement json, Type typeOfT,
JsonDeserializationContext context) throws JsonParseException {
JsonObject object = json.getAsJsonObject();
Employee result = null;
// if the employee has an assistant, she must be the CEO
JsonElement assistant = object.get("assistant");
if (assistant != null) {
result = new CEO();
((CEO) result).assistant = context.deserialize(assistant, Employee.class);
}
// only managers have minions
JsonElement minons = object.get("minions");
if (minons != null) {
if (result == null) {
result = new Manager();
}
((Manager) result).minions = context.deserialize(minons, Employee[].class);
}
if (result == null) {
result = new Employee();
}
result.userid = context.deserialize(object.get("userid"), String.class);
result.startDate = context.<Long>deserialize(object.get("startDate"), long.class);
return result;
}
}
static class Employee {
String userid;
long startDate;
Employee(String userid, long startDate) {
this.userid = userid;
this.startDate = startDate;
}
Employee() {}
}
static class Manager extends Employee {
Employee[] minions;
}
static class CEO extends Manager {
Employee assistant;
}
static class Company {
CEO ceo;
}
}
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