4解析json_使用cJSON库解析JSON

cJSON

Ultralightweight JSON parser in ANSI C

项目地址：https://gitcode.com/gh_mirrors/cj/cJSON

免费下载资源

GPUOpen

388人浏览 · 2021-01-06 12:51:21

GPUOpen · 2021-01-06 12:51:21 发布

cJSON库的下载

cJSON是一个基于C的JSON解析库，这个库非常简单，只有cJSON.c和cJSON.h两个文件，支持JSON的解析和封装，需要调用时，只需要#include "cJSON.h"就可以使用了，

库源码下载地址：cJSON download
JSON官方网站：json

只包含键值对的JSON字符串解析

JSON字符串：

{
    "name": "Andy",      //键值对1
    "age": 20              //键值对2
}

这个JSON对象只有两个键值对，键name对应字符串Andy，键age对应数字20。

void Parse_Str1(void)
{
    char str1[] = "{"name":"Andy","age":20}";
    cJSON *str1_json, *str1_name, *str1_age;
    printf("str1:%snn",str1);
    str1_json = cJSON_Parse(str1);   //创建JSON解析对象，返回JSON格式是否正确
    if (!str1_json)
    {
        printf("JSON格式错误:%snn", cJSON_GetErrorPtr()); //输出json格式错误信息
    }
    else
    {
        printf("JSON格式正确:n%snn",cJSON_Print(str1_json) );
        str1_name = cJSON_GetObjectItem(str1_json, "name"); //获取name键对应的值的信息
        if (str1_name->type == cJSON_String)
        {
            printf("姓名:%srn", str1_name->valuestring);
        }
        str1_age = cJSON_GetObjectItem(str1_json, "age");   //获取age键对应的值的信息
        if(str1_age->type==cJSON_Number)
        {
            printf("年龄:%drn", str1_age->valueint);
        }
        cJSON_Delete(str1_json);//释放内存
    }
}

运行结果：

包含数组的JSON字符串解析

JSON字符串：

{
    "location": [{
            "name": "Faye",
            "address": "北京"
        },
        {
            "name": "Andy",
            "address": "香港"
        }
    ],
    "time": "2018-11-17"
}

解析函数：

void Parse_Str2(void)
{

    char str2[] = "{"location":[{"name":"Faye","address":"北京"},{"name":"Andy","address":"香港"}],"time":"2018-11-17"}";

    cJSON *root = 0;
    cJSON *loc_json = 0;
    cJSON *name1_json,*name2_json;
    char *time_str, *str_tmp;

    root = cJSON_Parse(str2);
    if(!root)
        printf("str2 JSON格式错误:%s rn", cJSON_GetErrorPtr());
    else
    {
        printf("str2 JSON格式正确:n%sn",cJSON_Print(root));
        time_str = cJSON_GetObjectItem(root,"time")->valuestring;//time键值对
        printf("time:%sn", time_str);

        loc_json = cJSON_GetObjectItem(root,"location");
        if(loc_json)
        {
            name1_json = cJSON_GetArrayItem(loc_json,0);        //数组第0个元素
            str_tmp = cJSON_GetObjectItem(name1_json, "name")->valuestring;//name键对应的值
            printf("name1 is : %s rn", str_tmp);
            str_tmp = cJSON_GetObjectItem(name1_json, "address")->valuestring;//addr1键对应的值
            printf("addr1 is : %s rn", str_tmp);

            name2_json = cJSON_GetArrayItem(loc_json,1);       //数组第1个元素
            str_tmp = cJSON_GetObjectItem(name2_json, "name")->valuestring;
            printf("name2 is : %s rn", str_tmp);
            str_tmp = cJSON_GetObjectItem(name2_json, "address")->valuestring;
            printf("addr2 is : %s rn", str_tmp);
        }
    }
    cJSON_Delete(loc_json);
}

运行结果：

北京时间JSON数据解析

api地址：

http://api.k780.com:88/?app=life.time&appkey=10003&sign=b59bc3ef6191eb9f747dd4e83c99f2a4&format=json

JSON字符串：

{
    "success": "1",
    "result": {
        "timestamp": "1543922613",
        "datetime_1": "2018-12-04 19:23:33",
        "datetime_2": "2018年12月04日 19时23分33秒",
        "week_1": "2",
        "week_2": "星期二",
        "week_3": "周二",
        "week_4": "Tuesday"
    }
}

解析函数：

void Parse_BJ_Time(void)
{
    char bj_time_str[] = "{"success":"1","result":{"timestamp":"1542456793","datetime_1":"2018-11-17 20:13:13","datetime_2":"2018年11月17日 20时13分13秒","week_1":"6","week_2":"星期六","week_3":"周六","week_4":"Saturday"}}";

    cJSON *root;
    cJSON *result_json;
    char *datetime, *week;

    root = cJSON_Parse(bj_time_str);
    if(root)
    {
        printf("json格式正确:n%snn", cJSON_Print(root));
        result_json =  cJSON_GetObjectItem(root, "result");  //获取result键对应的值
        if(result_json)
        {
            datetime = cJSON_GetObjectItem(result_json, "datetime_2")->valuestring;
            printf("北京时间: %s rn", datetime);
            week = cJSON_GetObjectItem(result_json, "week_2")->valuestring;
            printf("星期: %s rn", week);
        }
    }
    cJSON_Delete(root);
    cJSON_Delete(result_json);
}

运行结果：

心知天气JSON数据解析

JSON字符串：

{
    "results": [{
        "location": {
            "id": "WS10730EM8EV",
            "name": "深圳",
            "country": "CN",
            "path": "深圳,深圳,广东,中国",
            "timezone": "Asia/Shanghai",
            "timezone_offset": "+08:00"
        },
        "daily": [{
            "date": "2018-11-18",
            "text_day": "多云",
            "code_day": "4",
            "text_night": "多云",
            "code_night": "4",
            "high": "26",
            "low": "20",
            "precip": "",
            "wind_direction": "无持续风向",
            "wind_direction_degree": "",
            "wind_speed": "10",
            "wind_scale": "2"
        }, {
            "date": "2018-11-19",
            "text_day": "小雨",
            "code_day": "13",
            "text_night": "小雨",
            "code_night": "13",
            "high": "25",
            "low": "20",
            "precip": "",
            "wind_direction": "无持续风向",
            "wind_direction_degree": "",
            "wind_speed": "10",
            "wind_scale": "2"
        }, {
            "date": "2018-11-20",
            "text_day": "小雨",
            "code_day": "13",
            "text_night": "小雨",
            "code_night": "13",
            "high": "25",
            "low": "21",
            "precip": "",
            "wind_direction": "无持续风向",
            "wind_direction_degree": "",
            "wind_speed": "10",
            "wind_scale": "2"
        }],
        "last_update": "2018-11-18T11:00:00+08:00"
    }]
}

解析函数：

void parse_seniverse_weather(void)
{
    char weather_str[] =
        "{"results":[{"location":{"id":"WS10730EM8EV","name":"深圳","country":"CN","path":"深圳,深圳,广东,中国","timezone":"Asia/Shanghai","timezone_offset":"+08:00"},"daily":[{"date":"2018-11-18","text_day":"多云","code_day":"4","text_night":"多云","code_night":"4","high":"26","low":"20","precip":"","wind_direction":"无持续风向","wind_direction_degree":"","wind_speed":"10","wind_scale":"2"},{"date":"2018-11-19","text_day":"小雨","code_day":"13","text_night":"小雨","code_night":"13","high":"25","low":"20","precip":"","wind_direction":"无持续风向","wind_direction_degree":"","wind_speed":"10","wind_scale":"2"},{"date":"2018-11-20","text_day":"小雨","code_day":"13","text_night":"小雨","code_night":"13","high":"25","low":"21","precip":"","wind_direction":"无持续风向","wind_direction_degree":"","wind_speed":"10","wind_scale":"2"}],"last_update":"2018-11-18T11:00:00+08:00"}]}";
    cJSON *root;
    cJSON *results;
    cJSON *last_update;
    cJSON *loc_json, *daily_json;
    cJSON *forecast_json;
    char *loc_tmp, *weather_tmp, *update_tmp;
    int i = 0;

    root = cJSON_Parse((const char*)weather_str);
    if(root)
    {
//        printf("JSON格式正确:n%snn",cJSON_Print(root));    //输出json字符串
        results = cJSON_GetObjectItem(root, "results");
        results = cJSON_GetArrayItem(results,0);
        if(results)
        {
            loc_json = cJSON_GetObjectItem(results, "location");   //得到location键对应的值，是一个对象

            loc_tmp = cJSON_GetObjectItem(loc_json, "id") -> valuestring;
            printf("城市ID:%sn",loc_tmp);
            loc_tmp = cJSON_GetObjectItem(loc_json, "name") -> valuestring;
            printf("城市名称:%sn",loc_tmp);
            loc_tmp = cJSON_GetObjectItem(loc_json, "timezone") -> valuestring;
            printf("城市时区:%snn",loc_tmp);

            daily_json = cJSON_GetObjectItem(results, "daily");
            if(daily_json)
            {
                for(i = 0; i < 3; i++)
                {
                    forecast_json = cJSON_GetArrayItem(daily_json, i);
                    weather_tmp = cJSON_GetObjectItem(forecast_json, "date") -> valuestring;
                    printf("日期:%srn", weather_tmp);
                    weather_tmp = cJSON_GetObjectItem(forecast_json, "code_day") -> valuestring;
                    printf("白天天气代码:%srn", weather_tmp);
                    weather_tmp = cJSON_GetObjectItem(forecast_json, "code_night") -> valuestring;
                    printf("晚上天气代码:%srn", weather_tmp);
                    weather_tmp = cJSON_GetObjectItem(forecast_json, "high") -> valuestring;
                    printf("最高温度:%srn", weather_tmp);
                    weather_tmp = cJSON_GetObjectItem(forecast_json, "low") -> valuestring;
                    printf("最低温度:%srn", weather_tmp);
                    weather_tmp = cJSON_GetObjectItem(forecast_json, "wind_direction_degree") -> valuestring;
                    printf("风向角度:%srn", weather_tmp);
                    weather_tmp = cJSON_GetObjectItem(forecast_json, "wind_scale") -> valuestring;
                    printf("风力:%srnn", weather_tmp);
                }
            }
            else
                printf("daily json格式错误rn");
            last_update = cJSON_GetObjectItem(results, "last_update");
            update_tmp = last_update->valuestring;
            if(last_update)
            {
                printf("更新时间:%srn", update_tmp);
            }
        }
        else
        {
            printf("results格式错误:%srn", cJSON_GetErrorPtr());
        }
    }
    else
    {
        printf("JSON格式错误rn");
    }
    cJSON_Delete(root);
    cJSON_Delete(results);
}

运行结果：

和风天气数据解析

JSON字符串：

{
    "HeWeather6": [{
        "basic": {
            "cid": "CN101010700",
            "location": "昌平",
            "parent_city": "北京",
            "admin_area": "北京",
            "cnty": "中国",
            "lat": "40.21808624",
            "lon": "116.23590851",
            "tz": "+8.00"
        },
        "update": {
            "loc": "2018-11-21 21:45",
            "utc": "2018-11-21 13:45"
        },
        "status": "ok",
        "daily_forecast": [{
            "cond_code_d": "100",
            "cond_code_n": "100",
            "cond_txt_d": "晴",
            "cond_txt_n": "晴",
            "date": "2018-11-21",
            "hum": "21",
            "mr": "16:02",
            "ms": "04:27",
            "pcpn": "0.0",
            "pop": "0",
            "pres": "1030",
            "sr": "07:08",
            "ss": "16:53",
            "tmp_max": "9",
            "tmp_min": "-3",
            "uv_index": "5",
            "vis": "10",
            "wind_deg": "323",
            "wind_dir": "西北风",
            "wind_sc": "1-2",
            "wind_spd": "4"
        }, {
            "cond_code_d": "100",
            "cond_code_n": "101",
            "cond_txt_d": "晴",
            "cond_txt_n": "多云",
            "date": "2018-11-22",
            "hum": "21",
            "mr": "16:36",
            "ms": "05:33",
            "pcpn": "0.0",
            "pop": "0",
            "pres": "1030",
            "sr": "07:09",
            "ss": "16:52",
            "tmp_max": "8",
            "tmp_min": "-4",
            "uv_index": "3",
            "vis": "20",
            "wind_deg": "35",
            "wind_dir": "东北风",
            "wind_sc": "1-2",
            "wind_spd": "5"
        }, {
            "cond_code_d": "101",
            "cond_code_n": "100",
            "cond_txt_d": "多云",
            "cond_txt_n": "晴",
            "date": "2018-11-23",
            "hum": "23",
            "mr": "17:15",
            "ms": "06:41",
            "pcpn": "0.0",
            "pop": "16",
            "pres": "1024",
            "sr": "07:10",
            "ss": "16:52",
            "tmp_max": "7",
            "tmp_min": "-2",
            "uv_index": "2",
            "vis": "20",
            "wind_deg": "305",
            "wind_dir": "西北风",
            "wind_sc": "1-2",
            "wind_spd": "3"
        }]
    }]
}

解析函数：

//解析和风天气，格式和心知天气非常像
void parse_heweather(void)
{
    char heweather_str[] = "{"HeWeather6":[{"basic":{"cid":"CN101010700","location":"昌平","parent_city":"北京","admin_area":"北京","cnty":"中国","lat":"40.21808624","lon":"116.23590851","tz":"+8.00"},"update":{"loc":"2018-11-21 21:45","utc":"2018-11-21 13:45"},"status":"ok","daily_forecast":[{"cond_code_d":"100","cond_code_n":"100","cond_txt_d":"晴","cond_txt_n":"晴","date":"2018-11-21","hum":"21","mr":"16:02","ms":"04:27","pcpn":"0.0","pop":"0","pres":"1030","sr":"07:08","ss":"16:53","tmp_max":"9","tmp_min":"-3","uv_index":"5","vis":"10","wind_deg":"323","wind_dir":"西北风","wind_sc":"1-2","wind_spd":"4"},{"cond_code_d":"100","cond_code_n":"101","cond_txt_d":"晴","cond_txt_n":"多云","date":"2018-11-22","hum":"21","mr":"16:36","ms":"05:33","pcpn":"0.0","pop":"0","pres":"1030","sr":"07:09","ss":"16:52","tmp_max":"8","tmp_min":"-4","uv_index":"3","vis":"20","wind_deg":"35","wind_dir":"东北风","wind_sc":"1-2","wind_spd":"5"},{"cond_code_d":"101","cond_code_n":"100","cond_txt_d":"多云","cond_txt_n":"晴","date":"2018-11-23","hum":"23","mr":"17:15","ms":"06:41","pcpn":"0.0","pop":"16","pres":"1024","sr":"07:10","ss":"16:52","tmp_max":"7","tmp_min":"-2","uv_index":"2","vis":"20","wind_deg":"305","wind_dir":"西北风","wind_sc":"1-2","wind_spd":"3"}]}]}";

    cJSON *root;
    cJSON *results;
    cJSON *basic_json, *update_json, *forecast_json;
    cJSON *daily_json;

    int i = 0;
    char *basic_tmp, *update_tmp, *status_tmp, *weather_tmp;
    root = cJSON_Parse(heweather_str);
    if(root)
    {
        results = cJSON_GetObjectItem(root, "HeWeather6");      //HeWeather键对应的值，是一个数组
        results = cJSON_GetArrayItem(results,0);
        if(results)
        {
            basic_json = cJSON_GetObjectItem(results, "basic");
            if(basic_json)
            {
                basic_tmp = cJSON_GetObjectItem(basic_json, "cid") -> valuestring;
                printf("城市ID:%sn",basic_tmp);
                basic_tmp = cJSON_GetObjectItem(basic_json, "location") -> valuestring;
                printf("县级市:%sn",basic_tmp);
                basic_tmp = cJSON_GetObjectItem(basic_json, "parent_city") -> valuestring;
                printf("地级市:%sn",basic_tmp);
                basic_tmp = cJSON_GetObjectItem(basic_json, "admin_area") -> valuestring;
                printf("所属省:%sn",basic_tmp);
                basic_tmp = cJSON_GetObjectItem(basic_json, "lat") -> valuestring;
                printf("纬度:%sn",basic_tmp);
                basic_tmp = cJSON_GetObjectItem(basic_json, "lon") -> valuestring;
                printf("经度:%snn",basic_tmp);
            }
            update_json = cJSON_GetObjectItem(results, "update");
            if(update_json)
            {
                update_tmp = cJSON_GetObjectItem(update_json, "loc") -> valuestring;
                printf("更新时间:%s(所在地时间)n", update_tmp);
                update_tmp = cJSON_GetObjectItem(update_json, "utc") -> valuestring;
                printf("更新时间:%s(世界时间)nn", update_tmp);
            }
            status_tmp = cJSON_GetObjectItem(results, "status") -> valuestring;
            printf("解析状态:%snn", status_tmp);
            daily_json = cJSON_GetObjectItem(results, "daily_forecast");
            if(daily_json)
            {
                for(i = 0; i < 3; i++)
                {
                    forecast_json = cJSON_GetArrayItem(daily_json, i);
                    weather_tmp = cJSON_GetObjectItem(forecast_json, "date") -> valuestring;
                    printf("日期:%srn", weather_tmp);
                    weather_tmp = cJSON_GetObjectItem(forecast_json, "cond_txt_d") -> valuestring;
                    printf("白天天气:%srn", weather_tmp);
                    weather_tmp = cJSON_GetObjectItem(forecast_json, "cond_txt_n") -> valuestring;
                    printf("晚上天气:%srn", weather_tmp);
                    weather_tmp = cJSON_GetObjectItem(forecast_json, "tmp_max") -> valuestring;
                    printf("最高温度:%srn", weather_tmp);
                    weather_tmp = cJSON_GetObjectItem(forecast_json, "tmp_min") -> valuestring;
                    printf("最低温度:%srn", weather_tmp);
                    weather_tmp = cJSON_GetObjectItem(forecast_json, "wind_deg") -> valuestring;
                    printf("风向角度:%srn", weather_tmp);
                    weather_tmp = cJSON_GetObjectItem(forecast_json, "wind_dir") -> valuestring;
                    printf("风向:%srn", weather_tmp);
                    weather_tmp = cJSON_GetObjectItem(forecast_json, "wind_sc") -> valuestring;
                    printf("风力:%srnn", weather_tmp);
                }
            }
        }
    }
    cJSON_Delete(root);
    cJSON_Delete(results);
    cJSON_Delete(basic_json);
    cJSON_Delete(update_json);
    cJSON_Delete(forecast_json);
    cJSON_Delete(daily_json);
}

运行结果：

源码下载及实用的API地址：

本项目CodeBlock工程源码下载：MyJSON
在线JSON格式校验工具：bejson
免费的天气api接口：天气API

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Ultralightweight JSON parser in ANSI C

最近提交(Master分支：2 个月前 )

424ce4ce This reverts commit 5b502cdbfb21fbe5f6cf9ffbd2b96e4281a741e6. Related to #860 4 个月前

32497300 - 5 个月前

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