JSON（JavaScript Object Notation）是一种轻量级的数据交换格式。用于数据转化传输，通用于PHP、Java、C++、C#、Python等编程语言的数据交换传输。它易于人阅读和编写，同时也易于机器解析和生成。

基本结构：对象、数组

GSON是Google提供的用来在Java对象和JSON数据之间进行映射的Java类库。可以将一个Json字符转成一个Java对象，或者将一个Java转化为Json字符串。

特点：a、快速、高效

    b、代码量少、简洁

    c、面向对象

      d、数据传递和解析方便

Json数据如下：

{"rating": {"max": 10, "numRaters": 348, "average": "7.0", "min": 0}, "subtitle": "", "author": ["[日] 片山恭一"], "pubdate": "2005-1", "tags": [{"count": 136, "name": "片山恭一", "title": "片山恭一"}, {"count": 63, "name": "日本", "title": "日本"}, {"count": 61, "name": "日本文学", "title": "日本文学"}, {"count": 38, "name": "小说", "title": "小说"}, {"count": 32, "name": "满月之夜白鲸现", "title": "满月之夜白鲸现"}, {"count": 15, "name": "爱情", "title": "爱情"}, {"count": 8, "name": "純愛", "title": "純愛"}, {"count": 8, "name": "外国文学", "title": "外国文学"}], "origin_title": "", "image": "https://img1.doubanio.com/mpic/s1747553.jpg", "binding": "平装", "translator": ["豫人"], "catalog": "", "pages": "180", "images": {"small": "https://img1.doubanio.com/spic/s1747553.jpg", "large": "https://img1.doubanio.com/lpic/s1747553.jpg", "medium": "https://img1.doubanio.com/mpic/s1747553.jpg"}, "alt": "http://book.douban.com/subject/1220562/", "id": "1220562", "publisher": "青岛出版社", "isbn10": "7543632608", "isbn13": "9787543632608", "title": "满月之夜白鲸现", "url": "http://api.douban.com/v2/book/1220562", "alt_title": "", "author_intro": "", "summary": "那一年，是听莫扎特、钓鲈鱼和家庭破裂的一年。说到家庭破裂，母亲怪自己当初没有找到好男人，父亲则认为当时是被狐狸精迷住了眼，失常的是母亲，但出问题的是父亲……。", "price": "15.00元"
}

我们解析出其中的title、publisher、summary和数组tags。

1、创建一个android工程，并在AndroidManifest.xml文件上添加网络权限

    <uses-permission android:name="android.permission.INTERNET"/>

2、请求网络数据并进行解析

MainActivity类：

package com.example.gsondemo;import java.util.ArrayList;import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.widget.Toast;import com.android.volley.Response.ErrorListener;
import com.android.volley.Response.Listener;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import com.example.bean.Book;
import com.example.bean.Tag;
import com.google.gson.Gson;public class MainActivity extends ActionBarActivity
{//请求接口private String url = "https://api.douban.com/v2/book/1220562";@Overrideprotected void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);getData();}/*** 获取网络数据*/private void getData(){//创建请求对象StringRequest request = new StringRequest(url, new Listener<String>() {@Overridepublic void onResponse(String response){Log.e("info", response);dealData(response);}}, new ErrorListener() {@Overridepublic void onErrorResponse(VolleyError error){Toast.makeText(MainActivity.this, "网络请求出错", Toast.LENGTH_SHORT).show();}});//把请求对象加入请求队列里面new Volley().newRequestQueue(getApplicationContext()).add(request);}public void dealData(String result){//实例化Gson对象Gson gson = new Gson();//把json字符串转化为对象Book book = gson.fromJson(result, Book.class);ArrayList<Tag> list = book.getTags();for (int i = 0; i < list.size(); i++){Tag tag = list.get(i);Log.e("name", tag.getName());}Toast.makeText(MainActivity.this, "标题：" + book.getTitle() + "  出版社：" + book.getPublisher()+ "   Tag:" + book.getTags().size(), 1).show();}
}

实体类Book：

package com.example.bean;import java.util.ArrayList;public class Book
{private String title;//标题private String publisher;//出版社private String summary;//概要private ArrayList<Tag> tags;public String getTitle(){return title;}public void setTitle(String title){this.title = title;}public String getPublisher(){return publisher;}public void setPublisher(String publisher){this.publisher = publisher;}public String getSummary(){return summary;}public void setSummary(String summary){this.summary = summary;}public ArrayList<Tag> getTags(){return tags;}public void setTags(ArrayList<Tag> tags){this.tags = tags;}}

Tag类：

package com.example.bean;public class Tag
{private String count;private String name;private String title;public String getCount(){return count;}public void setCount(String count){this.count = count;}public String getName(){return name;}public void setName(String name){this.name = name;}public String getTitle(){return title;}public void setTitle(String title){this.title = title;}}

好了，GSON的使用就是那么简单。

项目下载地址：http://download.csdn.net/detail/u013043346/9405847