使用cjson进行对象的嵌套封装

共分两个部分，1）创建json、2）解析json

1）创建嵌套json的代码

char * makeJson()

{

    cJSON * pRoot = NULL;

    cJSON * pSub_1 = NULL;

    cJSON * pSub_2 = NULL;



    if((pRoot = cJSON_CreateObject()) == NULL)

    {

        return NULL;

    }

    if((pSub_1 = cJSON_CreateObject()) == NULL)

    {

        return NULL;

    }

    if((pSub_2 = cJSON_CreateObject()) == NULL)

    {

        return NULL;

    }

    cJSON_AddStringToObject(pSub_2, "cStr", "ccccccc");



    cJSON_AddStringToObject(pSub_1, "bStr", "bbbbbbb");

    cJSON_AddItemToObject(pSub_1, "subobject_2", pSub_2);



    cJSON_AddStringToObject(pRoot, "aStr", "aaaaaaa");

    cJSON_AddItemToObject(pRoot, "subobject_1", pSub_1);

    cJSON_AddStringToObject(pRoot, "xStr", "xxxxxxx");



    //cJSON_PrintUnformatted : make json string for Unformatted

    //char * pJson = cJSON_PrintUnformatted(pRoot);



    char * pJson = cJSON_Print(pRoot);

    if(NULL == pJson)

    {

        cJSON_Delete(pRoot);

        return NULL;

    }

    return pJson;

}

2）解析json的代码

int parseJson(const char * pJson)

{

    if(NULL == pJson)

    {

        return 1;

    }

    cJSON * pRoot = cJSON_Parse(pJson);

    if(NULL == pRoot)

    {

        return 2;

    }

    cJSON * pSub_1 = cJSON_GetObjectItem(pRoot, "aStr");

    if(NULL == pSub_1)

    {

        cJSON_Delete(pRoot);

        return 3;

    }

    printf("get aStr : [%s]\n", pSub_1->valuestring);

    pSub_1 = cJSON_GetObjectItem(pRoot, "xStr");

    if(NULL == pSub_1)

    {

        cJSON_Delete(pRoot);

        return 4;

    }

    printf("get xStr : [%s]\n", pSub_1->valuestring);

    pSub_1 = cJSON_GetObjectItem(pRoot, "subobject_1");

    if(NULL == pSub_1)

    {

        cJSON_Delete(pRoot);

        return 5;

    }

    printf("get Sub Obj 1\n");

    cJSON * pSub_2 = cJSON_GetObjectItem(pSub_1, "bStr");

    if(NULL == pSub_2)

    {

        cJSON_Delete(pRoot);

        return 6;

    }

    printf("get bStr : [%s]\n", pSub_2->valuestring);

    pSub_2 = cJSON_GetObjectItem(pSub_1, "subobject_2");

    if(NULL == pSub_2)

    {

        cJSON_Delete(pRoot);

        return 7;

    }

    printf("get Obj 2\n");

    cJSON * pStr = cJSON_GetObjectItem(pSub_2, "cStr");

    if(NULL == pStr)

    {

        cJSON_Delete(pRoot);

        return 8;

    }

    printf("get cStr : [%s]\n", pStr->valuestring);



    cJSON_Delete(pRoot);

    return 0;

}

3）主函数

int main()

{

    char * pJson = makeJson();

    printf("JSON:\n%s\n", pJson);

    parseJson(pJson);

    free(pJson);



    return 0;

}

完整的代码请打开下面的代码或到百度网盘下载 http://pan.baidu.com/s/1pJ7KZSR

#include <stdio.h>

#include "cJSON.h"



char * makeJson()

{

    cJSON * pRoot = NULL;

    cJSON * pSub_1 = NULL;

    cJSON * pSub_2 = NULL;



    if((pRoot = cJSON_CreateObject()) == NULL)

    {

        return NULL;

    }

    if((pSub_1 = cJSON_CreateObject()) == NULL)

    {

        return NULL;

    }

    if((pSub_2 = cJSON_CreateObject()) == NULL)

    {

        return NULL;

    }

    cJSON_AddStringToObject(pSub_2, "cStr", "ccccccc");



    cJSON_AddStringToObject(pSub_1, "bStr", "bbbbbbb");

    cJSON_AddItemToObject(pSub_1, "subobject_2", pSub_2);



    cJSON_AddStringToObject(pRoot, "aStr", "aaaaaaa");

    cJSON_AddItemToObject(pRoot, "subobject_1", pSub_1);

    cJSON_AddStringToObject(pRoot, "xStr", "xxxxxxx");



    //cJSON_PrintUnformatted : make json string for Unformatted

    //char * pJson = cJSON_PrintUnformatted(pRoot);



    char * pJson = cJSON_Print(pRoot);

    if(NULL == pJson)

    {

        cJSON_Delete(pRoot);

        return NULL;

    }

    return pJson;

}



int parseJson(const char * pJson)

{

    if(NULL == pJson)

    {

        return 1;

    }

    cJSON * pRoot = cJSON_Parse(pJson);

    if(NULL == pRoot)

    {

        return 2;

    }

    cJSON * pSub_1 = cJSON_GetObjectItem(pRoot, "aStr");

    if(NULL == pSub_1)

    {

        cJSON_Delete(pRoot);

        return 3;

    }

    printf("get aStr : [%s]\n", pSub_1->valuestring);

    pSub_1 = cJSON_GetObjectItem(pRoot, "xStr");

    if(NULL == pSub_1)

    {

        cJSON_Delete(pRoot);

        return 4;

    }

    printf("get xStr : [%s]\n", pSub_1->valuestring);

    pSub_1 = cJSON_GetObjectItem(pRoot, "subobject_1");

    if(NULL == pSub_1)

    {

        cJSON_Delete(pRoot);

        return 5;

    }

    printf("get Sub Obj 1\n");

    cJSON * pSub_2 = cJSON_GetObjectItem(pSub_1, "bStr");

    if(NULL == pSub_2)

    {

        cJSON_Delete(pRoot);

        return 6;

    }

    printf("get bStr : [%s]\n", pSub_2->valuestring);

    pSub_2 = cJSON_GetObjectItem(pSub_1, "subobject_2");

    if(NULL == pSub_2)

    {

        cJSON_Delete(pRoot);

        return 7;

    }

    printf("get Obj 2\n");

    cJSON * pStr = cJSON_GetObjectItem(pSub_2, "cStr");

    if(NULL == pStr)

    {

        cJSON_Delete(pRoot);

        return 8;

    }

    printf("get cStr : [%s]\n", pStr->valuestring);



    cJSON_Delete(pRoot);

    return 0;

}



int main()

{

    char * pJson = makeJson();

    printf("JSON:\n%s\n", pJson);

    parseJson(pJson);

    free(pJson);



    return 0;

}

View Code

编译

$ gcc -o nestcjson nestcjson.c cjson.c -lm

注：编译时链接的库 -lm 是数学库，不加此库时 gcc 返回错误，错误代码如下

$ gcc -o nestcjson nestcjson.c cjson.c 

/tmp/ccugp95L.o: In function `parse_number':

cjson.c:(.text+0x402): undefined reference to `pow'

/tmp/ccugp95L.o: In function `print_number':

cjson.c:(.text+0x512): undefined reference to `floor'

collect2: ld 返回 1

运行

$ ./nestcjson 

JSON:

{

    "aStr":    "aaaaaaa",

    "subobject_1":    {

        "bStr":    "bbbbbbb",

        "subobject_2":    {

            "cStr":    "ccccccc"

        }

    },

    "xStr":    "xxxxxxx"

}

get aStr : [aaaaaaa]

get xStr : [xxxxxxx]

get Sub Obj 1

get bStr : [bbbbbbb]

get Obj 2

get cStr : [ccccccc]

 

作者：风波

mail : [email protected]