cJSON 官方测试程序详解

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我是靠谱客的博主顺心黄蜂，最近开发中收集的这篇文章主要介绍cJSON 官方测试程序详解，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

这是cJSON官方提供的一个测试小demo，比较好读。主要的作用是将内存中的数据，转化为json格式数据，以及将json格式的数据转为字符串输出到屏幕或文件中

#include <stdio.h>
#include <stdlib.h>
#include "cJSON.h"
/* Parse text to JSON, then render back to text, and print! */
/* 将字符串转为json格式，在将json格式文件转为字符串输出
*/
void doit(char *text)
{
char *out;cJSON *json;
json=cJSON_Parse(text);
// 将字符串转为cJSON对象
if (!json) {printf("Error before: [%s]n",cJSON_GetErrorPtr());}
// 转换失败输出错误提示
else
{
out=cJSON_Print(json);
// 将cJSON对象转为字符串
cJSON_Delete(json);
// 删除对象
printf("%sn",out);
// 输出字符串
free(out);
// 回收字符串内存
}
}
/* Read a file, parse, render back, etc. */
/* 从一个文件读取字符串，转成json格式，在转为字符串输出到屏幕上*/
void dofile(char *filename)
{
FILE *f;long len;char *data;
f=fopen(filename,"rb");fseek(f,0,SEEK_END);len=ftell(f);fseek(f,0,SEEK_SET);
// 计算字符串大小
data=(char*)malloc(len+1);fread(data,1,len,f);fclose(f);
// 从文件中读取data
doit(data);
free(data);
}
/* Used by some code below as an example datatype. */
/* 这个结构体是例子统一中一种常见的结构 */
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. */
/* Our "days of the week" array: 日期数组 */
const char *strings[7]={"Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"};
/* Our matrix: 矩阵数组 */
int numbers[3][3]={{0,-1,0},{1,0,0},{0,0,1}};
/* Our "gallery" item: 图片数组*/
int ids[4]={116,943,234,38793};
/* Our array of "records": 记录结构体*/
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"}};
/* Here we construct some JSON standards, from the JSON site. */
/* Our "Video" datatype: */
root=cJSON_CreateObject();
// 创建一个cJSON对象
cJSON_AddItemToObject(root, "name", cJSON_CreateString("Jack ("Bee") Nimble"));
// 添加一个数据
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("%sn",out);	free(out);	/* Print to text, Delete the cJSON, print it, release the string. */
/* Our "days of the week" array: */
root=cJSON_CreateStringArray(strings,7);
out=cJSON_Print(root);	cJSON_Delete(root);	printf("%sn",out);	free(out);
/* Our matrix: */
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("%sn",out);	free(out);
/* Our "gallery" item: */
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("%sn",out);	free(out);
/* Our array of "records": */
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, "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("%sn",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": 24n}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("../../tests/test1"); */
/*	dofile("../../tests/test2"); */
/*	dofile("../../tests/test3"); */
/*	dofile("../../tests/test4"); */
/*	dofile("../../tests/test5"); */
/* Now some samplecode for building objects concisely: */
create_objects();
return 0;
}