cJSON源码里的例子

这是cJSON源码里的例子,我觉得非常全面就贴出来留作备案.方便查找.

#include <stdio.h>

#include <stdlib.h>

#include "cJSON.h"

//#include "cJSON.c" 也可以包含C文件,就不使用库了.

/* Parse text to JSON, then render back to text, and print! */

void doit(char *text)

{

char *out;cJSON *json;

json=cJSON_Parse(text);

if (!json) {printf("Error before: [%s]\n",cJSON_GetErrorPtr());}

else

{

out=cJSON_Print(json);

cJSON_Delete(json);

printf("%s\n",out);

free(out);

}

}

/* Read a file, parse, render back, etc. */

void dofile(char *filename)

{

FILE *f=fopen(filename,"rb");

fseek(f,0,SEEK_END);

long len=ftell(f);

fseek(f,0,SEEK_SET);

char *data=(char*)malloc(len+1);

fread(data,1,len,f);

fclose(f);

doit(data);

free(data);

}

/* U example datatype. */

struct record {const char *precision;double lat,lon;const char *address,*city,*state,*zip,*country; };

/* Create a bunch of objects as demonstration. */

void create_objects()

{

cJSON *root,*fmt,*img,*thm,*fld;char *out;int i; /* declare a few. */

/* Here we construct some JSON standards, from the JSON site. */

/* Our "Video" datatype: */

root=cJSON_CreateObject();

cJSON_AddItemToObject(root, "name", cJSON_CreateString("Jack (\"Bee\") Nimble"));

cJSON_AddItemToObject(root, "format", fmt=cJSON_CreateObject());

cJSON_AddStringToObject(fmt,"type", "rect");

cJSON_AddNumberToObject(fmt,"width", 1920);

cJSON_AddNumberToObject(fmt,"height", 1080);

cJSON_AddFalseToObject (fmt,"interlace");

cJSON_AddNumberToObject(fmt,"frame rate", 24);

out=cJSON_Print(root); cJSON_Delete(root); printf("%s\n",out); free(out); /* Print to text, Delete the cJSON, print it, release the string. */

/* Our "days of the week" array: */

const char *strings[7]={"Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"};

root=cJSON_CreateStringArray(strings,7);

out=cJSON_Print(root); cJSON_Delete(root); printf("%s\n",out); free(out);

/* Our matrix: */

int numbers[3][3]={{0,-1,0},{1,0,0},{0,0,1}};

root=cJSON_CreateArray();

for (i=0;i<3;i++) cJSON_AddItemToArray(root,cJSON_CreateIntArray(numbers[i],3));

/* cJSON_ReplaceItemInArray(root,1,cJSON_CreateString("Replacement")); */

out=cJSON_Print(root); cJSON_Delete(root); printf("%s\n",out); free(out);

/* Our "gallery" item: */

int ids[4]={116,943,234,38793};

root=cJSON_CreateObject();

cJSON_AddItemToObject(root, "Image", img=cJSON_CreateObject());

cJSON_AddNumberToObject(img,"Width",800);

cJSON_AddNumberToObject(img,"Height",600);

cJSON_AddStringToObject(img,"Title","View from 15th Floor");

cJSON_AddItemToObject(img, "Thumbnail", thm=cJSON_CreateObject());

cJSON_AddStringToObject(thm, "Url", "http:/*www.example.com/image/481989943");

cJSON_AddNumberToObject(thm,"Height",125);

cJSON_AddStringToObject(thm,"Width","100");

cJSON_AddItemToObject(img,"IDs", cJSON_CreateIntArray(ids,4));

out=cJSON_Print(root); cJSON_Delete(root); printf("%s\n",out); free(out);

/* Our array of "records": */

struct record fields[2]={

{"zip",37.7668,-1.223959e+2,"","SAN FRANCISCO","CA","94107","US"},

{"zip",37.371991,-1.22026e+2,"","SUNNYVALE","CA","94085","US"}};

root=cJSON_CreateArray();

for (i=0;i<2;i++)

{

cJSON_AddItemToArray(root,fld=cJSON_CreateObject());

cJSON_AddStringToObject(fld, "precision", fields[i].precision);

cJSON_AddNumberToObject(fld, "Latitude", fields[i].lat);

cJSON_AddNumberToObject(fld, "Longitude", fields[i].lon);

cJSON_AddStringToObject(fld, "Address", fields[i].address);

cJSON_AddStringToObject(fld, "City", fields[i].city);

cJSON_AddStringToObject(fld, "State", fields[i].state);

cJSON_AddStringToObject(fld, "State", fields[i].state);

cJSON_AddStringToObject(fld, "Zip", fields[i].zip);

cJSON_AddStringToObject(fld, "Country", fields[i].country);

}

/* cJSON_ReplaceItemInObject(cJSON_GetArrayItem(root,1),"City",cJSON_CreateIntArray(ids,4)); */

out=cJSON_Print(root); cJSON_Delete(root); printf("%s\n",out); free(out);

}

int main (int argc, const char * argv[]) {

/* a bunch of json: */

char text1[]="{\n\"name\": \"Jack (\\\"Bee\\\") Nimble\", \n\"format\": {\"type\": \"rect\", \n\"width\": 1920, \n\"height\": 1080, \n\"interlace\": false,\"frame rate\": 24\n}\n}";

char text2[]="[\"Sunday\", \"Monday\", \"Tuesday\", \"Wednesday\", \"Thursday\", \"Friday\", \"Saturday\"]";

char text3[]="[\n [0, -1, 0],\n [1, 0, 0],\n [0, 0, 1]\n ]\n";

char text4[]="{\n \"Image\": {\n \"Width\": 800,\n \"Height\": 600,\n \"Title\": \"View from 15th Floor\",\n \"Thumbnail\": {\n \"Url\":
\"http:/*www.example.com/image/481989943\",\n \"Height\": 125,\n \"Width\": \"100\"\n },\n \"IDs\": [116, 943, 234, 38793]\n }\n }";

char text5[]="[\n {\n \"precision\": \"zip\",\n \"Latitude\": 37.7668,\n \"Longitude\": -122.3959,\n \"Address\": \"\",\n \"City\": \"SAN FRANCISCO\",\n \"State\": \"CA\",\n \"Zip\": \"94107\",\n
\"Country\": \"US\"\n },\n {\n \"precision\": \"zip\",\n \"Latitude\": 37.371991,\n \"Longitude\": -122.026020,\n \"Address\": \"\",\n \"City\": \"SUNNYVALE\",\n \"State\": \"CA\",\n \"Zip\": \"94085\",\n
\"Country\": \"US\"\n }\n ]";

/* Process each json textblock by parsing, then rebuilding: */

// doit(text1);

// doit(text2);

// doit(text3);

// doit(text4);

// doit(text5);

/* Parse standard testfiles: */

// dofile("./test1");

/* dofile("../../tests/test2"); */

/* dofile("../../tests/test3"); */

/* dofile("../../tests/test4"); */

/* dofile("../../tests/test5"); */

/* Now some samplecode for building objects concisely: */

// create_objects();

return 0;

}