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Andorid中使用Gson和Fast-json解析库解析JSON数据---第三方库学习笔记(二)

2019-06-17 18:18 2181 查看

JSON介绍:

JSON:JavaScript对象表示法
JSON是存储和交换文本信息的语法。
特点:

  1. JSON是轻量级的文本数据交换格式
  2. JSON独立于语言和平台
  3. JSON具有自我描述性,更易理解
    JSON与XML比较:
    类似XML,比XML更小、更快、更易解析
  4. 没有结束标签
  5. 更短
  6. 读写速度更快
  7. 使用数组
  8. 不使用保留字

JSON语法:

  1. 数据在名称/值对中
  2. 数据有逗号分隔
  3. 花括号保存对象
  4. 方括号保存数组

    JSON值可以是:

  5. 数字(整数或浮点数)
  6. 字符串(在双引号中)
  7. 逻辑值(true或false)
  8. 数组(在方括号中)
  9. 对象(在花括号中)
  10. null

JSON对象在花括号中书写,对象可以包含多个键值对:
eg:

{"name":"zhang","sex":"男"}

JSON数组在方括号中书写,数组包含多个对象:
eg:

{
"students":[
{"name":"zhang","sex":"男"},
{"name":"hong","sex":"女"},
{"name":"fang","sex":"女"},
]
}

JSON第三方解析库介绍

Gson的简介和特点:
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字符串转成一个Java对象,或者反过来。
Gson的特点:

  1. 快速、高效
  2. 代码量小、简洁
  3. 面向对象(Gson处理和解析JSON是采用面向对象的方式)
  4. 数据传递和解析方便

Fast-json简介和特点:
Fastjson是一个性能很好的Java语言实现的JSON解析器和生成器,来自阿里巴巴的工程师开发。具有极快的性能,超越任何其他的Java json parser。

Fast-json特点:

  1. 快速FAST(比其他任何基于Java的解析器和生成器更快,包括jackson)
  2. 强大(支持普通JDK类包括任意Java Bean Class、Collection、Map、Date或enum)
  3. 零依赖(没有依赖其他任何类库,除了JDK)
  4. 支持注解、支持全类型序列化

解析JSON数据

1.使用Java自带的方法解析和生成json数据的方法:

要解析的文件内容:

{
"languages": [
{
"id": 1,
"ide": "Eclipse",
"name": "Java"
},
{
"id": 2,
"ide": "XCode",
"name": "Swift"
},
{
"id": 3,
"ide": "Visual Studio",
"name": "C#"
}

],
"cat": "it"
}
package com.example.myjsontest;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

System.out.println("123456789");
//      //解析JSON数据
//      dealJSON();
//生成JSON数据
createJSON();
}

/**
* 生成JSON数据
*/
private void createJSON() {
JSONObject root = new JSONObject();
try {
root.put("cat", "it");

//              {
//                  "id": 1,
//                  "ide": "Eclipse",
//                  "name": "Java"
//              }
JSONObject lan1 = new JSONObject();
lan1.put("id", 1);
lan1.put("ide", "Eclipse");
lan1.put("name", "Java");

//          {
//            "id": 2,
//            "ide": "XCode",
//            "name": "Swift"
//          }
JSONObject lan2 = new JSONObject();
lan2.put("id", 2);
lan2.put("ide", "XCode");
lan2.put("name", "Swift");

//          {
//            "id": 3,
//            "ide": "Visual Studio",
//            "name": "C#"
//          }
JSONObject lan3 = new JSONObject();
lan3.put("id", 3);
lan3.put("ide", "Visual Studio");
lan3.put("name", "C#");

JSONArray array = new JSONArray();
array.put(lan1);
array.put(lan2);
array.put(lan3);
root.put("languages", array);
System.out.println(root.toString());

} catch (JSONException e) {
e.printStackTrace();
}

}

/**
* 解析JSON数据
*/
private void dealJSON() {
System.out.println("---------");
try {
InputStreamReader inputStreamReader = new InputStreamReader(
getAssets().open("test.json"), "UTF-8");

BufferedReader bufferedReader = new BufferedReader(
inputStreamReader);
// 将文本中的所有数据都读取到一个StringBuiler中
String line;
StringBuilder builder = new StringBuilder();
while ((line = bufferedReader.readLine()) != null) {
builder.append(line);
}
bufferedReader.close();
inputStreamReader.close();

JSONObject root = new JSONObject(builder.toString());
System.out.println("cat=" + root.getString("cat"));

JSONArray jsonArray = root.getJSONArray("languages");
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
System.out.println("=============================");
System.out.println("id=" + jsonObject.getInt("id"));
System.out.println("ide=" + jsonObject.getString("ide"));
System.out.println("name=" + jsonObject.getString("name"));

}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
}
}

解析结果:

生成的json数据tostring()后的结果:

Gson基本用法:

  1. 定义实体类(注意:定义的实体类中属性名要与json返回的键名一致)
  2. 根据需要可以将JSON生成单个实体或列表实体集合

使用Gson解析JsonObject、JsonArray、将实体类转为JSON数据的例子:

GsonTest类:

package com.test.Gson;

import java.util.HashMap;
import java.util.Map;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;

import com.android.volley.AuthFailureError;
import com.android.volley.Request.Method;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import com.example.myjsontest.R;
import com.google.gson.Gson;

public class GsonTest extends Activity{

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

RequestPost();
}

private void RequestPost() {
String url = "http://apis.juhe.cn/ip/ip2addr?";
final String key = "6f4328d5a40d23cf9974a64976717ede";
final String ip = "www.baidu.com";

StringRequest stringRequest = new StringRequest(Method.POST, url, new Response.Listener<String>() {

@Override
public void onResponse(String arg0) {
System.out.println(arg0);
dealData(arg0);
}

}, new Response.ErrorListener() {

@Override
public void onErrorResponse(VolleyError arg0) {
System.out.println(arg0.toString());
}
}){
@Override
protected Map<String, String> getParams() throws AuthFailureError {

Map<String,String> map = new HashMap<String,String>();
map.put("ip", ip);
map.put("key", key);
return map;
}
};
Volley.newRequestQueue(getApplicationContext()).add(stringRequest);
}

//使用Gson解析JSON数据
private void dealData(String result) {
Gson gson = new Gson();
//fromJson()方法中分别是:要解析的数据,要解析成的类型
Info info = gson.fromJson(result, Info.class);
Log.i("tag", "location:"+info.getResult().getLocation());
}

}

Info类:

package com.test.Gson;

public class Info {

private String resultcode;
private String reason;
private String error_code;
private Tag result;

public Tag getResult() {
return result;
}

public void setResult(Tag result) {
this.result = result;
}

public String getResultcode() {
return resultcode;
}

public void setResultcode(String resultcode) {
this.resultcode = resultcode;
}

public String getReason() {
return reason;
}

public void setReason(String reason) {
this.reason = reason;
}

public String getError_code() {
return error_code;
}

public void setError_code(String error_code) {
this.error_code = error_code;
}

}

Tag类:

package com.test.Gson;

public class Tag {

private String area;
private String location;

public String getArea() {
return area;
}
public void setArea(String area) {
this.area = area;
}
public String getLocation() {
return location;
}
public void setLocation(String location) {
this.location = location;
}

}

获取到的JSON数据:

{
"resultcode": "200",
"reason": "Return Successd!",
"result": {
"area": "北京市",
"location": "百度公司电信节点"
},
"error_code": 0
}

运行结果:

Fast-json的基本用法:

  1. 定义实体类(注意:实体类中的属性名称要与JSON数据中的键名一致)
  2. 根据需要可以将JSON生成单个实体或列表实体集合

    使用Fast-json解析JsonObject、JsonArray、将实体类转为JSON数据的例子:

FastJsonTest类:

package com.test.fastjson;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;

import com.alibaba.fastjson.JSON;
import com.android.volley.Request.Method;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import com.example.myjsontest.R;

public class FastJsonTest extends Activity{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

RequestPost();
}

private void RequestPost() {

String url = "https://api.douban.com/v2/book/1220562";
StringRequest stringRequest = new StringRequest(Method.POST, url, new Response.Listener<String>() {

@Override
public void onResponse(String arg0) {
System.out.println(arg0);
dealData(arg0);
}

}, new Response.ErrorListener() {

@Override
public void onErrorResponse(VolleyError arg0) {
System.out.println(arg0.toString());
}
});

Volley.newRequestQueue(getApplicationContext()).add(stringRequest);
}

//使用Fast-json库解析JSON数据
private void dealData(String result) {
//parseObject()方法中参数说明:result 需要解析的JSON字符串、Book.class 要解析成的类型
Book book = JSON.parseObject(result, Book.class);
Log.i("tag", "书名:"+book.getTitle()+"内容摘要:"+book.getSummary()+"tags的size:"+book.getTags().size());
}
}

Book类:

package com.test.fastjson;

import java.util.ArrayList;

public class Book {

private String title;
private String publisher;
private String summary;
private String price;
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 String getPrice() {
return price;
}

public void setPrice(String price) {
this.price = price;
}

public ArrayList<Tag> getTags() {
return tags;
}

public void setTags(ArrayList<Tag> tags) {
this.tags = tags;
}

}

Tag类:

package com.test.fastjson;

public class Tag {

private String title;
private String name;
private String count;

public String getTitle() {
return title;
}

public void setTitle(String title) {
this.title = title;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public String getCount() {
return count;
}

public void setCount(String count) {
this.count = count;
}

}

获取到的JSON数据:

{
"rating": {
"max": 10,
"numRaters": 343,
"average": "7.0",
"min": 0
},
"subtitle": "",
"author": [
"[日] 片山恭一"
],
"pubdate": "2005-1",
"tags": [
{
"count": 133,
"name": "片山恭一",
"title": "片山恭一"
},
{
"count": 62,
"name": "日本",
"title": "日本"
},
{
"count": 60,
"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": "http://img3.douban.com/mpic/s1747553.jpg",
"binding": "平装",
"translator": [
"豫人"
],
"catalog": "\n      ",
"pages": "180",
"images": {
"small": "http://img3.douban.com/spic/s1747553.jpg",
"large": "http://img3.douban.com/lpic/s1747553.jpg",
"medium": "http://img3.douban.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"
}

运行结果截图:

如果想要将Book实体类或者Book实体类集合转换成JSON数据:
只需要在dealData()方法中添加如下代码:

//使用Fast-json库解析JSON数据
private void dealData(String result) {
//parseObject()方法中参数说明:result 需要解析的JSON字符串、Book.class 要解析成的类型
Book book = JSON.parseObject(result, Book.class);

Book book1 = new Book();
book1.setTitle("book1");
//将实体类对象转换成JSON数据
JSON.toJSON(book1);

Book book2 = new Book();
book2.setTitle("book2");
Book book3 = new Book();
book3.setTitle("book3");
List<Book> list = new ArrayList<Book>();
list.add(book1);
list.add(book2);
list.add(book3);
//将实体类集合转换为JSON数据
JSON.toJSON(list);

Log.i("tag", "书名:"+book.getTitle()+"内容摘要:"+book.getSummary()+"tags的size:"+book.getTags().size());
}

使用Gson或Fast-json库解析复杂的JSON数据:
FastAndGsonTest类:

package com.test.FastAndGson;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;

import com.alibaba.fastjson.JSON;
import com.android.volley.AuthFailureError;
import com.android.volley.Request.Method;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import com.example.myjsontest.R;

public class FastAndGsonTest extends Activity {

private ListView listView;
private BookListAdapter adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);

initView();
RequestPost();
}

private void initView() {
listView = (ListView) findViewById(R.id.id_listView);
}

private void RequestPost() {
String url = "http://japi.juhe.cn/book/recommend.from?";
final String key = "bf5cae62e7854e8969e51660c0adc910";
final String cat = "1";
final String ranks = "1";

StringRequest stringRequest = new StringRequest(Method.POST, url,
new Response.Listener<String>() {

@Override
public void onResponse(String arg0) {
System.out.println(arg0);
dealData(arg0);
}

}, new Response.ErrorListener() {

@Override
public void onErrorResponse(VolleyError arg0) {
System.out.println(arg0.toString());
}
}) {
@Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String, String> map = new HashMap<String, String>();
map.put("key", key);
map.put("cat", cat);
map.put("ranks", ranks);
return map;
}
};
Volley.newRequestQueue(getApplicationContext()).add(stringRequest);
}

private void dealData(String arg0) {
try {
//使用Fast-json库解析JSON数据
JSONObject resultObject = new JSONObject(arg0);
JSONObject dataObject = new JSONObject(resultObject.getString("result"));
ArrayList<Book> books = (ArrayList<Book>)JSON.parseArray(dataObject.getString("data"),Book.class);

//使用Gson库解析JSON数据
//          Gson gson = new Gson();
//          JSONObject resultObject = new JSONObject(arg0);
//          JSONObject dataObject = new JSONObject(resultObject.getString("result"));
//          Type listType = new TypeToken<ArrayList<Book>>() {
//          }.getType();
//          ArrayList<Book> books = gson.fromJson(dataObject.getString("data"),
//                  listType);

adapter = new BookListAdapter(FastAndGsonTest.this, books);
listView.setAdapter(adapter);
} catch (JSONException e) {
e.printStackTrace();
}

}

}

BookListAdapter类:

package com.test.FastAndGson;

import java.util.ArrayList;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import com.example.myjsontest.R;

public class BookListAdapter extends BaseAdapter{
private Context context;
private ArrayList<Book> list;

public BookListAdapter(Context context,ArrayList<Book> books){
this.context = context;
this.list = books;
}

@Override
public int getCount() {
return list.size();
}

@Override
public Object getItem(int position) {
return list.get(position);
}

@Override
public long getItemId(int position) {
return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if(holder==null){
convertView = View.inflate(context, R.layout.item_list, null);
holder = new ViewHolder();
holder.textView = (TextView) convertView.findViewById(R.id.id_textView);
convertView.setTag(holder);
}else{
holder = (ViewHolder) convertView.getTag();
}
Book book = list.get(position);
holder.textView.setText(book.getTitle()+"\n"+book.getCode());
return convertView;
}

class ViewHolder{
TextView textView;
}

}

Book类:

package com.test.FastAndGson;

public class Book {

private String title;
private String code;

public String getTitle() {
return title;
}

public void setTitle(String title) {
this.title = title;
}

public String getCode() {
return code;
}

public void setCode(String code) {
this.code = code;
}

}

获取的JSON数据:

{
"error_code": 0,
"reason": "Success",
"result": {
"data": [
{
"title": "美国70年:大而不倒的阴谋政治",
"code": 39705
},
{
"title": "关情",
"code": 39706
},
{
"title": "维基大战前传1:阿桑奇和他的黑客战友",
"code": 39707
},
{
"title": "大逆转:大败局之后的复活密码",
"code": 39708
},
{
"title": "我是夜场女企划(全本)",
"code": 39709
},
{
"title": "杜月笙传(上、中、下)",
"code": 39710
},
{
"title": "你走以后",
"code": 39711
},
{
"title": "创造贝因美——服务经济时代的公司革命",
"code": 39712
},
{
"title": "9999滴眼泪",
"code": 39716
},
{
"title": "新闻人",
"code": 39717
},
{
"title": "草莽生长:十大首富的创富之道",
"code": 39718
},
{
"title": "1块变10块的投资分配法",
"code": 39719
},
{
"title": "阿嬷,我回来了",
"code": 39720
},
{
"title": "换个方式好好爱",
"code": 39721
},
{
"title": "权力野兽朱元璋3(大结局)",
"code": 39722
},
{
"title": "流动中国",
"code": 39723
},
{
"title": "问你爸去",
"code": 39724
},
{
"title": "667公里的吻",
"code": 39725
},
{
"title": "给你一个公司,看你怎么管",
"code": 39726
},
{
"title": "职场中50个第一次",
"code": 39727
},
{
"title": "从零开始学K线",
"code": 39728
},
{
"title": "非常印度",
"code": 39729
},
{
"title": "远征流在缅北的血",
"code": 39731
},
{
"title": "这样喝咖啡最健康",
"code": 39732
},
{
"title": "扑克脸:Lady Gaga传",
"code": 39733
},
{
"title": "换个姿势爱",
"code": 39734
},
{
"title": "30年后,你拿什么养活自己2",
"code": 39735
},
{
"title": "暗权力——黑道启示录",
"code": 39736
},
{
"title": "重金求子",
"code": 39738
},
{
"title": "成为作家",
"code": 39739
},
{
"title": "寻路中国:从乡村到工厂的自驾之旅",
"code": 39740
},
{
"title": "一个人的旅行",
"code": 39741
},
{
"title": "女人29岁",
"code": 39742
},
{
"title": "有爱无爱一身轻",
"code": 39743
},
{
"title": "嫁人的资本",
"code": 39744
},
{
"title": "小女人隐私报告2",
"code": 39745
},
{
"title": "小女人隐私报告1",
"code": 39746
},
{
"title": "冷血感情信箱",
"code": 39747
},
{
"title": "为什么男人爱说谎女人爱哭",
"code": 39748
},
{
"title": "像女人一样行动,像男人一样思考",
"code": 39749
},
{
"title": "男人来自火星·白金升级版",
"code": 39750
},
{
"title": "放下",
"code": 39751
},
{
"title": "爱的锁钥",
"code": 39752
},
{
"title": "爱情纪",
"code": 39753
},
{
"title": "婚恋中女人不能犯的100个错误",
"code": 39754
},
{
"title": "婚恋中男人不能犯的100个错误",
"code": 39755
},
{
"title": "再婚书",
"code": 39756
},
{
"title": "幸福太太完全自助宝典",
"code": 39757
},
{
"title": "婚恋急诊室",
"code": 39758
},
{
"title": "男人是野生动物 女人是筑巢动物",
"code": 39759
}
]
}
}

运行结果截图:

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