C语言解析JSON(HeWearher)测试(nxjson)

devcang

1. //input是输入json
   
2. const nx_json *root = nx_json_get(nx_json_parse_utf8((char*)input), "HeWeather5")->children.first; //HeWeather5
   
3.         if (! root) {
   
4.                 printf("parse json failed,root\n");
   
5.                 return 0;
   
6.         }
   
7.         if(0!=strcmp("ok", nx_json_get(root, "status")->text_value)){// HeWeather5.status;
   
8.                 printf("json status ! OK\n");
   
9.                 return 0;
   
10.         }
    
11. 
    
12.         const nx_json *city, *basic, *now, *suggestion, *forecast, *tmp;
    
13.        
    
14.         city=nx_json_get(root->children.first, "city");//HeWeather5.aqi.city aqi->children.first;
    
15.         printf("指数=%s ",  nx_json_get(city, "aqi")->text_value);//aqi，空气质量指数
    
16.         printf("%s,", nx_json_get(city, "qlty")->text_value);//qlty
    
17.         printf("co=%s,",   nx_json_get(city, "co")->text_value);  //co
    
18.         printf("no2=%s,",  nx_json_get(city, "no2")->text_value); //no2
    
19.         printf("o3=%s,",   nx_json_get(city, "o3")->text_value);  //o3
    
20.         printf("pm10=%s,", nx_json_get(city, "pm10")->text_value);//pm10
    
21.         printf("pm25=%s,", nx_json_get(city, "pm25")->text_value);//pm25
    
22.         printf("so2=%s\n", nx_json_get(city, "so2")->text_value); //so2
    
23.         // printf("%s-%s\n", city->children.first->key, city->children.first->text_value);        //aqi:"36"
    
24.         // printf("%s-%s\n", city->children.first->next->key, city->children.first->next->text_value);//co:"0.8"
    
25.        
    
26.         basic=nx_json_get(root, "basic");
    
27.         printf("更新:%s", nx_json_get(nx_json_get(basic, "update"), "loc")->text_value);//update
    
28.         printf("@%s,%s,", nx_json_get(basic, "lat")->text_value, nx_json_get(basic, "lon")->text_value);//lat,lon
    
29.         printf("%s,%s\n", nx_json_get(basic, "city")->text_value, nx_json_get(basic, "cnty")->text_value);//cnty
    
30.        
    
31.         now=nx_json_get(root, "now");
    
32.         printf("即时: %s ", nx_json_get(nx_json_get(now, "cond"), "txt")->text_value);//cond
    
33.         printf("%s℃,",   nx_json_get(now, "tmp")->text_value);//tmp
    
34.         printf("%s%%,", nx_json_get(now, "hum")->text_value);//hum
    
35.         printf("%spa,",  nx_json_get(now, "pres")->text_value);//pres
    
36.         tmp=nx_json_get(now, "wind");
    
37.         printf("wind:deg=%s/%s sc=%s %sm/s,",
    
38.                 nx_json_get(tmp, "deg")->text_value,
    
39.                 nx_json_get(tmp, "dir")->text_value,
    
40.                 nx_json_get(tmp, "sc")->text_value,
    
41.                 nx_json_get(tmp, "spd")->text_value);//wind
    
42.         printf("vis=%s,",   nx_json_get(now, "vis")->text_value);//vis
    
43.         printf("pcpn=%s,",  nx_json_get(now, "pcpn")->text_value);//pcpn
    
44.         printf("dew=%s,",   nx_json_get(now, "dew")->text_value);//dew
    
45.         printf("fl=%s\n",    nx_json_get(now, "fl")->text_value);//fl
    
46.        
    
47.         suggestion=nx_json_get(root, "suggestion");//生活指引
    
48.         printf("空气=%s\n",    nx_json_get(nx_json_get(suggestion, "air"), "brf")->text_value);//air
    
49.         printf("身感=%s\n",    nx_json_get(nx_json_get(suggestion, "comf"), "brf")->text_value);//comf
    
50.         printf("穿着=%s,%s\n", nx_json_get(nx_json_get(suggestion, "drsg"), "brf")->text_value, nx_json_get(nx_json_get(suggestion, "drsg"), "txt")->text_value);//drsg
    
51.         printf("运动=%s\n",    nx_json_get(nx_json_get(suggestion, "sport"), "brf")->text_value);//sport
    
52.         printf("出行=%s\n",    nx_json_get(nx_json_get(suggestion, "trav"), "brf")->text_value);//trav
    
53.         printf("紫外=%s\n",  nx_json_get(nx_json_get(suggestion, "uv"), "brf")->text_value);//uv
    
54.        
    
55.         forecast=nx_json_get(root, "daily_forecast")->children.first; //预报，一般有3天的预报
    
56.         for(; forecast; forecast=forecast->next) {
    
57.                 printf("%s ", nx_json_get(forecast, "date")->text_value);//date
    
58.                 printf("%s|l%s ",  nx_json_get(nx_json_get(forecast, "cond"), "txt_d")->text_value, nx_json_get(nx_json_get(forecast, "cond"), "txt_n")->text_value);//cond
    
59. //                printf("cloud=%s,", nx_json_get(forecast, "cloud")->text_value);//sr
    
60.                 tmp=nx_json_get(forecast, "tmp");
    
61.                 printf("%s-%s℃,", nx_json_get(tmp, "min")->text_value, nx_json_get(tmp, "max")->text_value);//tmp
    
62.                 printf("%s%%,", nx_json_get(forecast, "hum")->text_value);//hum
    
63.                 printf("%spa,",  nx_json_get(forecast, "pres")->text_value);//pres
    
64.                 tmp=nx_json_get(forecast, "wind");
    
65.                 printf("wind:dir=%s/%s sc=%s %sm/s,", nx_json_get(tmp, "deg")->text_value, nx_json_get(tmp, "dir")->text_value, nx_json_get(tmp, "sc")->text_value, nx_json_get(tmp, "spd")->text_value);//wind
    
66.                 printf("vis=%s,",   nx_json_get(forecast, "vis")->text_value);//vis
    
67.                 printf("pcpn=%s/",  nx_json_get(forecast, "pcpn")->text_value);//pcpn
    
68.                 printf("%s%%,",   nx_json_get(forecast, "pop")->text_value);//pop
    
69.                 printf("uv=%s,",    nx_json_get(forecast, "uv")->text_value);//uv
    
70.                 tmp=nx_json_get(forecast, "astro");
    
71.                 printf("s=%s-%s,", nx_json_get(tmp, "sr")->text_value, nx_json_get(tmp, "ss")->text_value);//sr
    
72.                 printf("m=%s-%s", nx_json_get(tmp, "mr")->text_value, nx_json_get(tmp, "ms")->text_value);//mr
    
73.                 printf("\n");
    
74.         }
    
75. 
    
76.         nx_json_free(root);
    
77.         nx_json_free(city);
    
78.         nx_json_free(basic);
    
79.         nx_json_free(now);
    
80.         nx_json_free(suggestion);
    
81.         nx_json_free(forecast);
    
82.         nx_json_free(tmp);

复制代码

有一定注释，放到notepad++那样的编辑器，会比较容易查看。几乎是全解析了，取所需要的field显示就是了。

最近气温偏低，于是就想经常看看天气。手机的天气也可以，但参数不够多。

选择缘由：nxjson 来源github上（多刷新几次，能取到），是轻量级，直接引用源文件，不必编译成库文件。可以逐个枚举，也可以按名称选取，比较方便。通用、方便移植（对单片机有些困难，但对一般的arm/arduino级别的，应该不吃力）。
clone下来后附带有测试案例、有编译说明，等，比较详细。

作者说明：
Very small JSON parser written in C.
## Features
- Parses JSON from null-terminated string
- Easy to use tree traversal API
- Allows // line and /\* block \*/ comments (except before colon ':')
- Operates on single-byte or multi-byte characters (like UTF-8), but not on wide characters
- Unescapes string values (including Unicode codepoints & surrogates)
- Can use custom Unicode encoder, UTF-8 encoder built in
- Can use custom memory allocator
- Can use custom macro to print errors
- Test suite included

## Limitations
- Non-validating parser; might accept invalid JSON (eg., extra or missing commas, comments, octal or hex numeric values, etc.)



在ubuntu上测试结果
谨作例子指引，谢谢观看。

devcang

Linux 2.6.32.16 #136 Fri Feb 4 11:20:00 CST 2022 armv4tl GNU/Linux

重新嵌入编译，在ARM LINUX上执行

tom666123

大牛，收下膝盖。