【Linux 应用】jsonc解析数据。

最近弄了下jsonc解析数据，记录一下，方便以后查阅。

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一、jsonc接口

1、解析成json对象

1.1、将字符串解析成json对象

json_object* json_tokener_parse(const char *str);

1.2、将文件解析成json对象

json_object* json_object_from_file(const char *filename);

2、解析json对象

2.1、取值

json_object* json_object_object_get(json_object* jso, const char *key)

2.2、转化值

//转int类型
int32_t json_object_get_int(struct json_object *obj);
//转string类型
const char* json_object_get_string(struct json_object *obj);

2.3、解析数组对象

json_object* json_object_array_get_idx(struct json_object *obj , int idx);

3、释放json对象

json_object_put(struct json_object *obj);

二、实例

数据

{
    "program":[
        {
            "assetId":"1595839049646290",
            "channelId":"102457500",
            "channelName":"TEST1",
            "dayOfWeek":"6",
            "endDateTime":"20200802012100",
            "programId":"102456699",
            "programName":"test1",
            "startDateTime":"20200801233500",
            "status":"1",
            "viewLevel":"0"
        },
        {
            "assetId":"1595839049643424",
            "channelId":"102457500",
            "channelName":"TEST1",
            "dayOfWeek":"6",
            "endDateTime":"20200801233500",
            "programId":"102456698",
            "programName":"test1",
            "startDateTime":"20200801215900",
            "status":"1",
            "viewLevel":"0"
        }
    ],
    "restartAtToken":"1000",
    "totalResults":"29"
}

解析

#include 
#include 

#include 
#include "json_object.h"
#include "json_object_private.h"

#include "jsonDataParse.h"
#include "debugUtils.h"
#include "bits.h"

//#define DEBUG 1

int iParseJsonString(json_object *retJson, char *pcKey, char *pcValue, int length)
{
    json_object *jsTemp = NULL;
    
    if(retJson == NULL || is_error(jsTemp))
    {
		printf("the retJson is error \n");
        return -1;
    }
    jsTemp = json_object_object_get(retJson, pcKey);
	if(NULL == jsTemp || is_error(jsTemp))
	{
		printf("the jsTemp : NULL\n");
        return -1;
	}
    
    strncpy(pcValue, (char *)json_object_get_string(jsTemp), length);
    pcValue[length -1] = '\0';
    return 0;
}

int iParseJsonint(json_object *retJson, char *pcKey, int *pcValue)
{
    json_object *jsTemp = NULL;
    
    if(retJson == NULL || is_error(jsTemp))
    {
		printf("the retJson is error \n");
        return -1;
    }

    jsTemp = json_object_object_get(retJson, pcKey);
	if(NULL == jsTemp || is_error(jsTemp))
	{
		printf("the jsTemp : NULL\n");
        return -1;
	}
    *pcValue = (int)json_object_get_int(jsTemp);
    return 0;
}

 
SHOW_LIST_t * parse_showlist(char *databuf, int *length)
{
	int i = 0;
	SHOW_LIST_t *listdata = NULL;
	char totalResults[8]  = {0};
	char restartAtToken[8]  = {0};
	json_object *jsonobj = NULL;
	json_object *tmpjson = NULL;
	json_object *datajson = NULL;
    
	if(NULL == databuf)
	{
		printf("the databuf is NULL ...\n");
        return NULL;
	}
    
	jsonobj = json_tokener_parse(databuf);
	if (is_error(jsonobj))
	{
		printf("the jsonobj is error \n");
        return NULL;
	}
    
    iParseJsonString(jsonobj, "totalResults", totalResults, sizeof(totalResults));
    if(0 == strlen(totalResults)){
        printf("totalResults is NULL\n");
        return NULL;
    }
    (*length) = atoi(totalResults);
    if((*length) <= 0){
        printf("totalResults : 0\n");
        return NULL;
    }
    GUI_DEBUG("totalResults : %s\n",totalResults);
    
    iParseJsonString(jsonobj, "restartAtToken", restartAtToken, sizeof(restartAtToken));
    GUI_DEBUG("restartAtToken : %s\n",restartAtToken);
	
    listdata = (struct SHOW_LIST_t *)malloc(sizeof(struct SHOW_LIST_t)*(*length));
    if (NULL == listdata){
        printf("parse_showlist : malloc error \n");
        return NULL;
    }
    memset(listdata, 0, sizeof(struct SHOW_LIST_t)*(*length));
    
	tmpjson = json_object_object_get(jsonobj , "program");
	for(i = 0; i <(*length); i++)
	{
		datajson = json_object_array_get_idx(tmpjson , i);
        if(NULL == datajson){
            break;
        }
        
        iParseJsonString(datajson, "assetId", listdata[i].assetId, sizeof(listdata[i].assetId));
        iParseJsonString(datajson, "channelId", listdata[i].channelId, sizeof(listdata[i].channelId));
        iParseJsonString(datajson, "channelName", listdata[i].channelName, sizeof(listdata[i].channelName));
        iParseJsonString(datajson, "dayOfWeek", listdata[i].dayOfWeek, sizeof(listdata[i].dayOfWeek));
        iParseJsonString(datajson, "endDateTime", listdata[i].endDateTime, sizeof(listdata[i].endDateTime));
        iParseJsonString(datajson, "programId", listdata[i].programId, sizeof(listdata[i].programId));
        iParseJsonString(datajson, "programName", listdata[i].programName, sizeof(listdata[i].programName));
        iParseJsonString(datajson, "startDateTime", listdata[i].startDateTime, sizeof(listdata[i].startDateTime));
        iParseJsonString(datajson, "status", listdata[i].status, sizeof(listdata[i].status));
        iParseJsonString(datajson, "viewLevel", listdata[i].viewLevel, sizeof(listdata[i].viewLevel));
	}
	
	json_object_put(jsonobj);
    
    #ifdef DEBUG
	GUI_DEBUG("------------the program -----------------\n");
	SHOW_LIST_t *oo = listdata;
	GUI_DEBUG("{\n\t\"program\":\n\t\t[\n");
	for(i = 0 ; i < (*length); i++)
	{
		GUI_DEBUG("\t\t\t\{\"id\":\"%s\",\"name\":\"%s\",\"type\":%s,\"count\":%s\}\n",oo->assetId , oo->channelId,oo->channelName,oo->dayOfWeek);
        oo++;
	}
	GUI_DEBUG("\t\t],\n\t\"totalResults\":%s,\n\t\"restartAtToken\":%s,\n\t\n}\n",totalResults, restartAtToken);
    #endif
    
	return listdata;
}

三、结束语

解析json数据四步走：

1、将其转化成json对象

2、解析成json对象

3、转化成对应的数据类型

4、释放json对象

5、需要强调的一点是错误判断不是判空能检测出来的。要用到is_error接口，如下使用：

    jsonobj = json_tokener_parse(databuf);
    if (is_error(jsonobj))
    {
        printf("the jsonobj is error \n");
        return NULL;
    }