Java-json

Posted 2021-07-21 人塞不能怨

Java-Json

使用fastjson解析json格式字符串

Json格式字符串

在json字符串中，{}相当于java对象，[]相当于java数组

Java处理json文件

1. 创建Maven项目并添加依赖

<dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>fastjson</artifactId>
      <version>1.2.75</version>
</dependency>

2. 主要操作
解析json字符串

String data = "{\\"code\\":200,\\"msg\\":\\"ok\\",\\"data\\":[{\\"ip\\":\\"121.56.213.160\\",\\"port\\":36410,\\"expire_time\\":\\"2021-05-08 15:45:26\\",\\"city\\":\\"\\\\u9521\\\\u6797\\\\u90ed\\\\u52d2\\\\u76df\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"114.227.161.205\\",\\"port\\":23564,\\"expire_time\\":\\"2021-05-08 15:55:40\\",\\"city\\":\\"\\\\u5e38\\\\u5dde\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"117.91.252.183\\",\\"port\\":5412,\\"expire_time\\":\\"2021-05-08 15:53:29\\",\\"city\\":\\"\\\\u626c\\\\u5dde\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"114.100.1.151\\",\\"port\\":766,\\"expire_time\\":\\"2021-05-08 15:50:34\\",\\"city\\":\\"\\\\u9a6c\\\\u978d\\\\u5c71\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"60.166.102.108\\",\\"port\\":5412,\\"expire_time\\":\\"2021-05-08 15:35:37\\",\\"city\\":\\"\\\\u5408\\\\u80a5\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"49.87.194.11\\",\\"port\\":36410,\\"expire_time\\":\\"2021-05-08 15:48:42\\",\\"city\\":\\"\\\\u6dee\\\\u5b89\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"113.110.45.234\\",\\"port\\":36410,\\"expire_time\\":\\"2021-05-08 15:40:46\\",\\"city\\":\\"\\\\u63ed\\\\u9633\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"49.86.179.128\\",\\"port\\":5412,\\"expire_time\\":\\"2021-05-08 15:40:56\\",\\"city\\":\\"\\\\u626c\\\\u5dde\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"117.60.239.175\\",\\"port\\":3617,\\"expire_time\\":\\"2021-05-08 15:58:12\\",\\"city\\":\\"\\\\u6dee\\\\u5b89\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"121.56.213.229\\",\\"port\\":5412,\\"expire_time\\":\\"2021-05-08 15:40:33\\",\\"city\\":\\"\\\\u9521\\\\u6797\\\\u90ed\\\\u52d2\\\\u76df\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"113.231.37.204\\",\\"port\\":5412,\\"expire_time\\":\\"2021-05-08 15:45:21\\",\\"city\\":\\"\\\\u8fbd\\\\u9633\\",\\"isp\\":\\"\\\\u8054\\\\u901a\\"},{\\"ip\\":\\"121.56.215.168\\",\\"port\\":894,\\"expire_time\\":\\"2021-05-08 15:50:26\\",\\"city\\":\\"\\\\u9521\\\\u6797\\\\u90ed\\\\u52d2\\\\u76df\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"49.87.201.5\\",\\"port\\":3617,\\"expire_time\\":\\"2021-05-08 15:35:16\\",\\"city\\":\\"\\\\u6dee\\\\u5b89\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"36.56.101.254\\",\\"port\\":894,\\"expire_time\\":\\"2021-05-08 15:50:53\\",\\"city\\":\\"\\\\u9a6c\\\\u978d\\\\u5c71\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"125.105.176.171\\",\\"port\\":766,\\"expire_time\\":\\"2021-05-08 15:52:56\\",\\"city\\":\\"\\\\u8862\\\\u5dde\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"114.97.194.216\\",\\"port\\":23564,\\"expire_time\\":\\"2021-05-08 15:35:53\\",\\"city\\":\\"\\\\u5408\\\\u80a5\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"42.56.34.65\\",\\"port\\":766,\\"expire_time\\":\\"2021-05-08 15:40:55\\",\\"city\\":\\"\\\\u8fbd\\\\u9633\\",\\"isp\\":\\"\\\\u8054\\\\u901a\\"},{\\"ip\\":\\"114.100.2.128\\",\\"port\\":23564,\\"expire_time\\":\\"2021-05-08 15:50:21\\",\\"city\\":\\"\\\\u9a6c\\\\u978d\\\\u5c71\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"60.166.104.104\\",\\"port\\":5412,\\"expire_time\\":\\"2021-05-08 15:40:17\\",\\"city\\":\\"\\\\u5408\\\\u80a5\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"},{\\"ip\\":\\"60.166.103.174\\",\\"port\\":5412,\\"expire_time\\":\\"2021-05-08 15:40:29\\",\\"city\\":\\"\\\\u5408\\\\u80a5\\",\\"isp\\":\\"\\\\u7535\\\\u4fe1\\"}]}\\n";

JsonObject json = JSON.parseObject(data);
System.out.println(json.getIntValue("code"));
System.out.println(json.getString("msg"));
System.out.println("=====================");
JSONArray jarr = json.getJSONArray("data");

for (int i = 0; i < jarr.size(); i++){
	json = jarr.getJSONObject(i);
	System.out.println(json.getString("ip"));
	System.out.println(json.getIntValue("port"));
	System.out.println(json.getDate("expire_time"));
	System.out.println("-----------------")
}

输出

200
ok
======================
121.56.213.160
36410
Sat May 08 15:45:26 CST 2021
-------------------------------
...

java object to json

//先创建Entity和Hobby两个实体类
Entity e = new Entity("henry",18,new Hobby(1,"游泳")，new Hobby(2,"LOL"));
String s = JSON.toJSONString(e);
System.out.println(s);

输出

{"age":18,"hobbies":[{"id":1,"name":"游泳"},{"id":2,"name":"LOL"}],"name":"henry"}