Java之JSON处理（JSONObjectJSONArray）

Posted 2020-10-24 星瑞的随笔

依赖包：json-20180130.jar

MAVEN地址：

1         <dependency>
2             <groupId>org.json</groupId>
3             <artifactId>json</artifactId>
4             <version>20180130</version>
5         </dependency>

 

比较简单，一看就懂，源码如下：

 1 package json;
 2 
 3 import org.json.JSONArray;
 4 import org.json.JSONObject;
 5 
 6 import java.util.HashMap;
 7 import java.util.Map;
 8 
 9 /**
10  * JSONObject和JSONArray使用：进行JSON对象转换和操作
11  * JSONObject：处理JSON串，多种构造方法，可用于多类型转账。
12  * JSONArray：JSON数组，有顺序
13  */
14 public class JsonFirst {
15     public static void main(String[] args) {
16         // 1、定义一个json对象
17         JSONObject jo = new JSONObject();
18         jo.put("id", "1");
19         jo.put("name", "tom");
20         jo.put("age", "25");
21         System.out.println("1、JSONObject: " + jo);
22         // 获取name值
23         String name = jo.getString("name");
24         System.out.println("查询name:" + name);
25 
26         // 2、定义一个Json数组，数组有顺序
27         JSONArray ja = new JSONArray();
28         ja.put(0, "yang");
29         ja.put(1, "li");
30         ja.put(2, "zhang");
31         ja.put(4, "fouth");
32         System.out.println("2、JSONArray数组: " + ja);
33         // 获取第四个值
34         String fouth = ja.getString(4);
35         System.out.println("查询第四个：" + fouth);
36 
37         // 3、json中添加json对象组成复杂JSON
38         jo.put("Object", ja);
39         System.out.println("3、添加JSON对象后: " + jo);
40 
41         // 4、String转换为JSON（复杂JSON处理）
42         String str = "{\"name\":\"tom\",\"Object\":[\"yang\",\"li\",\"zhang\",null,\"fouth\"],\"id\":\"1\",\"age\":\"25\"}";
43         JSONObject jo2 = new JSONObject(str);
44         System.out.println("4、String转换为JSON:" + jo2);
45         System.out.println("name属性值:" + jo2.getString("name"));
46         System.out.println("Object属性值:" + jo2.get("Object").toString());
47         // 删除Object属性值
48         jo.remove("Object");
49         System.out.println("删除Object属性值:" + jo);
50 
51         // 5、map和JSON转换
52         Map<String, String> map1 = new HashMap<String, String>();
53         map1.put("name", "Alexia");
54         map1.put("sex", "female");
55         map1.put("age", "23");
56         JSONObject jo3 = new JSONObject(map1);
57         System.out.println("5.1 map转JSON:" + jo3);
58         Map<String, Object> map2 = new HashMap<String, Object>();
59         map2 = jo3.toMap();
60         System.out.println("5.2 JSON转map:" + map2);
61 
62         // 6、JSONArray中添加map和JSON对象
63         JSONArray jo4 = new JSONArray();
64         jo4.put(map1);
65         jo4.put(1, "333");
66         jo4.put(jo);
67         System.out.println("6、JSONArray中添加map和JSON对象：" + jo4);
68 
69     }
70 }

 

运行结果：

1、JSONObject: {"name":"tom","id":"1","age":"25"}
查询name:tom
2、JSONArray数组: ["yang","li","zhang",null,"fouth"]
查询第四个：fouth
3、添加JSON对象后: {"name":"tom","Object":["yang","li","zhang",null,"fouth"],"id":"1","age":"25"}
4、String转换为JSON:{"name":"tom","Object":["yang","li","zhang",null,"fouth"],"id":"1","age":"25"}
name属性值:tom
Object属性值:["yang","li","zhang",null,"fouth"]
删除Object属性值:{"name":"tom","id":"1","age":"25"}
5.1 map转JSON:{"name":"Alexia","age":"23","sex":"female"}
5.2 JSON转map:{sex=female, name=Alexia, age=23}
6、JSONArray中添加map和JSON对象：[{"name":"Alexia","age":"23","sex":"female"},"333",{"name":"tom","id":"1","age":"25"}]