1 什么是JSON?

    JSON(JavaScript Object Notation) 是一种轻量级的数据交换格式。 易于人阅读和编写。同时也易于机器解析和生成。 它基于javascript Programming Language, Standard ECMA-262 3rd Edition - December 1999的一个子集。 JSON采用完全独立于语言的文本格式，但是也使用了类似于C语言家族的习惯（包括C, C++, C#, Java, JavaScript, Perl, Python等）。 这些特性使JSON成为理想的数据交换语言。Fastjson是国内著名的电子商务互联网公司阿里巴巴内部开发的用于java后台处理json格式数据的一个工具包，包括“序列化”和“反序列化”两部分，它具备如下特征

a)速度最快，测试表明，fastjson具有极快的性能，超越任其他的java json parser。包括自称最快的jackson
b)功能强大，完全支持java bean、集合、Map、日期、Enum，支持范型，支持自省
c)无依赖，能够直接运行在Java SE 5.0以上版本
d)支持Android
e)这是fastJson的网址：http://code.alibabatech.com/wiki/display/FastJSON/Overview其中包含了json数据处理的教程，jar下载地址，example样例等

2 JSONObject与JSONArray

● JSONObject
json对象，就是一个键对应一个值，使用的是大括号{ }，如：{key:value}
● JSONArray
json数组，使用中括号[ ],只不过数组里面的项也是json键值对格式的
注意：Json对象中是添加的键值对,JSONArray中添加的是Json对象
简单示例：

public class JsonTest {public static void main(String[] args) {// Json对象中是添加的键值对,JSONArray中添加的是Json对象JSONObject jsonObject = new JSONObject();JSONObject jsonObject1 = new JSONObject();JSONArray jsonArray = new JSONArray();jsonObject1.put("001","jack");// JSONObject 对象中添加键值对jsonObject.put("key","values");// 将JSONObject对象添加到json数组中jsonArray.add(jsonObject);jsonArray.add(jsonObject1);System.out.println(jsonArray.toString());// 输出结果: [{"key":"values"},{"001":"jack"}]}
}

官方示例：

package com.orange.com.orange.json.fastjson;import java.util.List;public class Group {private int id;private String name;List<User> users;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public List<User> getUsers() {return users;}public void setUsers(List<User> users) {this.users = users;}
}

class User{private int id;private String name;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}
}

package com.orange.com.orange.json.fastjson;import com.alibaba.fastjson.JSON;import java.util.ArrayList;
import java.util.List;public class FastJsonTest {public static void main(String[] args) {Group group = new Group();group.setId(0);group.setName("admin");User user = new User();user.setId(001);user.setName("guest");User user1 = new User();user1.setId(002);user1.setName("root");List<User> users = new ArrayList<User>();users.add(user);users.add(user1);group.setUsers(users);String json = JSON.toJSONString(group);System.out.println(json);// 输出: {"id":0,"name":"admin","users":[{"id":1,"name":"guest"},{"id":2,"name":"root"}]}}
}

3 fastJson处理json数据格式的代码样例

package test.com.orange.com.orange.json.fastjson;import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.serializer.SerializerFeature;
import com.orange.com.orange.json.fastjson.People;
import org.junit.Test;import static org.junit.Assert.*;public class FastJsonTestTest {/*** 序列化*/@Testpublic void toJsonString() {People people = new People("001","tom",12);String text = JSON.toJSONString(people);System.out.println(text);// 输出结果: {"age":12,"id":"001","name":"tom"}}/*** 反序列为Json对象*/@Testpublic void parseJsonObject(){String text = "{\"age\":12,\"id\":\"001\",\"name\":\"tom\"}";People people = (People) JSON.parseObject(text,People.class);System.out.println("parseBeanObject()方法：people==" + people.getId() + "," + people.getName() + "," + people.getAge());// 输出结果为: parseBeanObject()方法：people==001,tom,12}/*** 将javaBean转化为json对象*/@Testpublic void bean2Json(){People people = new People("002","jack",23);JSONObject jsonObject = (JSONObject) JSON.toJSON(people);System.out.println("bean2Json()方法：jsonObject==" + jsonObject);// 输出结果: bean2Json()方法：jsonObject=={"name":"jack","id":"002","age":23}}/*** 全序列化 直接把java bean序列化为json文本之后，能够按照原来的类型反序列化回来。支持全序列化，需要打开SerializerFeature.WriteClassName特性*/@Testpublic void parseJSONAndBeanEachother(){People people = new People("002","jack",23);SerializerFeature[] featureArr = { SerializerFeature.WriteClassName };String text = JSON.toJSONString(people, featureArr);System.out.println("parseJSONAndBeanEachother()方法：text==" + text);// 输出结果：parseJSONAndBeanEachother()方法：text=={"@type":"com.wanggs.com.wanggs.json.fastjson.People","age":23,"id":"002","name":"jack"}People people1 = (People) JSON.parse(text);System.out.println("parseJSONAndBeanEachother()方法：People==" + people1.getId() + "," + people1.getName() + "," + people1.getAge());// 输出结果：userObj==testFastJson001,maks,105}}

javaBean类People.java:

package com.orange.com.orange.json.fastjson;public class People {private String id;private String name;private int age;public People() {}public People(String id, String name, int age) {this.id = id;this.name = name;this.age = age;}public String getId() {return id;}public void setId(String id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}
}

4 深入Json

package test.com.orange.com.orange.json.fastjson;import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.orange.com.orange.json.fastjson.Address;
import com.orange.com.orange.json.fastjson.People;
import org.junit.Test;import java.util.*;import static org.junit.Assert.*;public class FastJsonTest1Test {/*** 数组转json字符串*/@Testpublic void array2Json() {String[] arr = {"bill", "green", "maks", "jim"};String jsonText = JSON.toJSONString(arr);System.out.println("array2Json()方法：jsonText==" + jsonText);// 输出结果：jsonText==["bill","green","maks","jim"]}/*** json格式字符串转数组*/@Testpublic void json2Array() {String jsonText = "[\"bill\",\"green\",\"maks\",\"jim\"]";JSONArray jsonArray = JSON.parseArray(jsonText);System.out.println("json2Array()方法：jsonArray==" + jsonArray);// 输出结果：jsonArray==["bill","green","maks","jim"]}/*** 数组转json格式字符串*/@Testpublic void array2Json2() {People people = new People("001", "tom", 12);People people1 = new People("002", "jack", 23);People people2 = new People("003", "mair", 22);People[] peoples = new People[]{people, people1, people2};String jsonText = JSON.toJSONString(peoples);System.out.println("array2Json2()方法：jsonText==" + jsonText);//输出结果：array2Json2()方法：jsonText==[{"age":12,"id":"001","name":"tom"},{"age":23,"id":"002","name":"jack"},{"age":22,"id":"003","name":"mair"}]}/*** json格式字符串转数组*/@Testpublic void json2Array2() {String jsonText = "[{\"age\":12,\"id\":\"001\",\"name\":\"tom\"},{\"age\":23,\"id\":\"002\",\"name\":\"jack\"},{\"age\":22,\"id\":\"003\",\"name\":\"mair\"}]";JSONArray jsonArr = JSON.parseArray(jsonText);System.out.println("json2Array2()方法：jsonArr==" + jsonArr);// 输出结果：json2Array2()方法：jsonArr==[{"name":"tom","id":"001","age":12},{"name":"jack","id":"002","age":23},{"name":"mair","id":"003","age":22}]}/*** list集合转json格式字符串*/@Testpublic void list2Json() {List<People> list = new ArrayList<People>();list.add(new People("001", "tom", 12));list.add(new People("002", "jack", 23));list.add(new People("003", "mair", 22));String jsonText = JSON.toJSONString(list);System.out.println("list2Json()方法：jsonText==" + jsonText);// 输出的结果为: [{"age":12,"id":"001","name":"tom"},{"age":23,"id":"002","name":"jack"},{"age":22,"id":"003","name":"mair"}]}/*** map转json格式字符串*/@Testpublic void map2Json() {Map map = new HashMap();Address address1 = new Address("广东省","深圳市","科苑南路","580053");map.put("address1", address1);Address address2 = new Address("江西省","南昌市","阳明路","330004");map.put("address2", address2);Address address3 = new Address("陕西省","西安市","长安南路","710114");map.put("address3", address3);String jsonText = JSON.toJSONString(map, true);System.out.println("map2Json()方法：jsonText=="+jsonText);//输出结果：jsonText=={"address1":{"city":"深圳市","post":"580053","province":"广东省","street":"科苑南路"},"address2":{"city":"南昌市","post":"330004","province":"江西省","street":"阳明路"},"address3":{"city":"西安市","post":"710114","province":"陕西省","street":"长安南路"}}}/*** json转map*/@Testpublic void json2Map(){String text = "{\"age\":12,\"id\":\"001\",\"name\":\"tom\"}";Map<String,Object> map = JSON.parseObject(text);System.out.println("json2Map()方法：map=="+map);//输出结果：{"name":"tom","id":"001","age":12}Set<String> set = map.keySet();for(String key : set){System.out.println(key+"--->"+map.get(key));}}
}

5 技巧

package com.orange.com.orange.json.fastjson;import com.alibaba.fastjson.JSON;public class CustomText {/*** touser : OPENID* msgtype : text* text : {"content":"Hello World"}*/
//{"msgtype":"text","text":{"content":"Hello World"},"touser":"OPENID"}private String touser;private String msgtype;private TextBean text;public static class TextBean {/*** content : Hello World*/private String content;public String getContent() {return content;}public void setContent(String content) {this.content = content;}}public String getTouser() {return touser;}public void setTouser(String touser) {this.touser = touser;}public String getMsgtype() {return msgtype;}public void setMsgtype(String msgtype) {this.msgtype = msgtype;}public TextBean getText() {return text;}public void setText(TextBean text) {this.text = text;}
}

class Test{public static void main(String[] args) {CustomText customText = new CustomText();customText.setTouser("OPENID");customText.setMsgtype("text");CustomText.TextBean textBean =  new CustomText.TextBean();textBean.setContent("Hello World");customText.setText(textBean);String json = JSON.toJSONString(customText);System.out.println(json);//{"msgtype":"text","text":{"content":"Hello World"},"touser":"OPENID"}}/*** {"touser":"OPENID","msgtype":"text","text":{"content":"Hello World"}}*/}

6 归纳六种方式json转map

package com.orange.com.orange.json.fastjson;import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;import java.util.Map;
import java.util.Set;public class FastJsonTest1 {public static void main(String[] args) {String str = "{\"0\":\"zhangsan\",\"1\":\"lisi\",\"2\":\"wangwu\",\"3\":\"maliu\"}";//第一种方式Map maps = (Map)JSON.parse(str);System.out.println("这个是用JSON类来解析JSON字符串!!!");for (Object map : maps.entrySet()){System.out.println(((Map.Entry)map).getKey()+"     " + ((Map.Entry)map).getValue());}//第二种方式Map mapTypes = JSON.parseObject(str);System.out.println("这个是用JSON类的parseObject来解析JSON字符串!!!");for (Object obj : mapTypes.keySet()){System.out.println("key为："+obj+"值为："+mapTypes.get(obj));}//第三种方式Map mapType = JSON.parseObject(str,Map.class);System.out.println("这个是用JSON类,指定解析类型，来解析JSON字符串!!!");for (Object obj : mapType.keySet()){System.out.println("key为："+obj+"值为："+mapType.get(obj));}//第四种方式/*** JSONObject是Map接口的一个实现类*/Map json = (Map) JSONObject.parse(str);System.out.println("这个是用JSONObject类的parse方法来解析JSON字符串!!!");for (Object map : json.entrySet()){System.out.println(((Map.Entry)map).getKey()+"  "+((Map.Entry)map).getValue());}//第五种方式/*** JSONObject是Map接口的一个实现类*/JSONObject jsonObject = JSONObject.parseObject(str);System.out.println("这个是用JSONObject的parseObject方法来解析JSON字符串!!!");for (Object map : json.entrySet()){System.out.println(((Map.Entry)map).getKey()+"  "+((Map.Entry)map).getValue());}//第六种方式/*** JSONObject是Map接口的一个实现类*/Map mapObj = JSONObject.parseObject(str,Map.class);System.out.println("这个是用JSONObject的parseObject方法并执行返回类型来解析JSON字符串!!!");for (Object map: json.entrySet()){System.out.println(((Map.Entry)map).getKey()+"  "+((Map.Entry)map).getValue());}String strArr = "{{\"0\":\"zhangsan\",\"1\":\"lisi\",\"2\":\"wangwu\",\"3\":\"maliu\"}," +"{\"00\":\"zhangsan\",\"11\":\"lisi\",\"22\":\"wangwu\",\"33\":\"maliu\"}}";// JSONArray.parse()System.out.println(json);}
}

package com.orange.com.orange.json.fastjson;import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;import java.util.*;public class FastJsonTest {public static void main(String[] args) {String json = "[{\"id\":1,\"type\":\"cycle\",\"attribute\":{\"center\":\"(10.4, 123.345)\", \"radius\":67.4}},{\"id\":2,\"type\":\"polygon\",\"attribute\":[{\"vertex\":\"(10.4, 133.345)\"}, {\"vertex\":\"(10.4, 143.345)\"}]}]";JSONArray array = JSON.parseArray(json);System.out.println(array.getJSONObject(0).getJSONObject("attribute").get("center"));System.out.println(array.getJSONObject(1).getJSONArray("attribute").getJSONObject(1).get("vertex"));// 输出结果为: (10.4, 123.345) (10.4, 143.345)}
}

7 项目使用总结

   对于JSONArray和JSONObject而言，常用于项目中的io传输或发送http请求中参数中，因为是最接近二进制的，也防止信息丢失的一种可能，然而对于对象的形式返回给前端的话，可以通过map形式传递给前端，使用方式上存在多种可能，得具体情况具体分析了

fastjson中JSONArray和JSONObject相关推荐

FastJson 中 jsonArray 转换成 list 集合的方法
前些天发现了一个巨牛的人工智能学习网站,通俗易懂,风趣幽默,忍不住分享一下给大家.点击跳转到教程. 今天在写代码时候,遇到了需要将json文本改成jsonobject对象,然后将jsonobject对 ...
fastjson中List和JSONArray的相互转换
1.fastjson中List和JSONArray的相互转换 (1)List转换为JSONArray List<T> list = new ArrayList<T>(); JS ...
对象转数组_fastJson中java对象 jsonObject jsonArray之间转换
一.介绍简介:JSON(JavaScript Object Notation) 是一种轻量级的数据交换格式二.使用 1.java对象转jsonObject User u = new User(); ...
JsonArray或者JsonObject转字符串后里面带有转义字符或者反斜杠的处理方式
一般出现这种toString后json串里面带有转义字符的原因是往jsonObject中直接put了String类型的内容,比如jsonObject.put("key"," ...
Android开发将List转化为JsonArray和JsonObject
客户端需要将List<Object>转化为JsonArray和JsonObject的方法: 首先,List中的Object的属性需要是public: class Person {publi ...
fastjson中对象转换中看到的一些现象
引出的背景今天在用IDEA进行代码review的时候.发现有的小伙伴在代码上显示了一条波浪线.仔细一看代码如下: JSON.parseObject(value, List.class) 这里使用了f ...
java JSONArray与JSONObject的增删改查大解析一篇让你不再迷茫
前提相关的jar包 https://download.csdn.net/download/qq_37591637/11162911 JSONArray与JSONObject的区别 JSONArr ...
fastjson中@JSONType的使用-排除字段
@JSONType(includes = {""}) 以后,通过下面的方式这个类的属性就不会转化到jsonObject中了. JSONObject jsonObject = (JS ...
[fastjson] - fastjson中 JSONObject 和 JSONArray
/*** 对jsonObject对象进行key的获取* @param jsonObject*/public ArrayList<String> jsonKeyRecursion(JSONO ...

fastjson中JSONArray和JSONObject