Json工具类库之Gson实战笔记

浏览数：55 / 时间：2015年06月09日

日常接口的数据传输通常使用xml或者json来传递数据，xml较庞大但是描述数据能力十分出众，json数据结构较小而且支持ajax传输，xml在数据传输和解析资源占用都比较逊色于json。因此日常的接口通常都使用json的数据格式进行传输。一方面能减少应用或者客户端如Android应用解析数据的资源占用，另一方面节省宝贵的数据传输时间。

Java中对Json的序列化和反序列化常用的工具有Json、Fastjson、Gson等。其中，Fastjson是阿里巴巴的开源产品，用Java语言实现，号称是速度最快的Json序列化工具。

今天学习了Gson工具，并做了Demo加深学习印象，直接贴上代码在代码中说明问题：

Person类:

 1 /*
 2  * Copyright 2013 Alibaba.com All right reserved. This software is the
 3  * confidential and proprietary information of Alibaba.com ("Confidential
 4  * Information"). You shall not disclose such Confidential Information and shall
 5  * use it only in accordance with the terms of the license agreement you entered
 6  * into with Alibaba.com.
 7  */
 8 package com.yunos.tv.common.util;
 9 
10 import java.lang.reflect.Type;
11 import java.util.ArrayList;
12 import java.util.HashMap;
13 import java.util.List;
14 import java.util.Map;
15 
16 import com.google.gson.Gson;
17 import com.google.gson.reflect.TypeToken;
18 
19 /**
20  * 类GsonTest.java的实现描述：TODO 类实现描述
21  * @author riqi 2013年8月5日 下午10:26:28
22  */
23 
24 class Person {
25 
26     private String name;
27 
28     private int    age;
29 
30     private Family family;
31 
32     public Person(String name, int age, Family family) {
33         super();
34         this.name = name;
35         this.age = age;
36         this.family = family;
37     }
38 
39     public Family getFamily() {
40         return family;
41     }
42 
43     public void setFamily(Family family) {
44         this.family = family;
45     }
46 
47     @Override
48     public String toString() {
49         return "Person [name=" + name + ", age=" + age + ", family=" + family + "]";
50     }
51 }

Family类:

 1 class Family {
 2 
 3     private String father;
 4 
 5     private String mother;
 6 
 7     public Family(String father, String mother) {
 8         super();
 9         this.father = father;
10         this.mother = mother;
11     }
12 
13     @Override
14     public String toString() {
15         return "Family [father=" + father + ", mother=" + mother + "]";
16     }
17 
18 }

测试过程:

 1 public class GsonTest {
 2 
 3     public static Gson gson = new Gson();
 4 
 5     public static void main(String[] args) {
 6         String name = "riqi";
 7         int age = 26;
 8         Family family = new Family("爸爸", "妈妈");
 9 
10         // 序列化Map
11         Map<String, Object> userMap = new HashMap<String, Object>();
12         userMap.put("name", name);
13         userMap.put("age", age);
14         System.out.println(gson.toJson(userMap)); //{"age":26,"name":"riqi"}
15 
16         // 序列化List
17         List<Object> userList = new ArrayList<Object>();
18         userList.add(name);
19         userList.add(age);
20         System.out.println(gson.toJson(userList)); //["riqi",26]
21 
22         // 序列化对象
23         System.out.println(gson.toJson(family)); //{"father":"爸爸","mother":"妈妈"}
24 
25         // 借助TypeToken泛型实现单个对象序列化和反序列化
26         Person person = new Person(name, age, family);
27         Type personType = new TypeToken<Person>() {
28         }.getType();
29         String personJsonTo = gson.toJson(person, personType);
30         Person personJsonFrom = gson.fromJson(personJsonTo, personType);
31         Family familyJsonFrom = personJsonFrom.getFamily();
32         System.out.println(personJsonTo); //{"name":"riqi","age":26,"family":{"father":"爸爸","mother":"妈妈"}}
33         System.out.println(personJsonFrom);//Person [name=riqi, age=26, family=Family [father=爸爸, mother=妈妈]]
34         System.out.println(familyJsonFrom);//Family [father=爸爸, mother=妈妈]
35 
36         // 借助TypeToken泛型实现对象列表序列化和反序列化
37         List<Person> personList = new ArrayList<Person>();
38         Type personListType = new TypeToken<List<Person>>() {
39         }.getType();
40         for (int i = 0; i < 2; i++) {
41             Person personTmp = new Person(name, age + i, family); // 年龄做了变化
42             personList.add(personTmp);
43         }
44         String personListJsonTo = gson.toJson(personList, personListType);
45         List<Person> personListJsonFrom = gson.fromJson(personListJsonTo, personListType);
46         System.out.println(personListJsonTo);//[{"name":"riqi","age":26,"family":{"father":"爸爸","mother":"妈妈"}},{"name":"riqi","age":27,"family":{"father":"爸爸","mother":"妈妈"}}]
47         System.out.println(personListJsonFrom);//[Person [name=riqi, age=26, family=Family [father=爸爸, mother=妈妈]], Person [name=riqi, age=27, family=Family [father=爸爸, mother=妈妈]]]
48     }
49 }