json-c库例子

jsonc库使用

作者：wangkangluo1 | 出处：博客园 | 2011/12/15 15:12:28 | 阅读58次

原文地址：

1: 下载json-c库源码文件

json-c-0.9.tar.gz

2: 编译

3: json-c常用函数

(1): 将一个json文件转换成object对象:

struct json_object* json_object_from_file(char *filename)

举例：

json_object *pobj = NULL;

pobj = json_object_from_file("/home/boy/tmp/test/jsontest/test.json");

(2): 将json-object写回文件

int json_object_to_file(char *filename, struct json_object *obj)

举例:

json_object_from_file("/home/boy/tmp/test/jsontest/test.json", pobj);

(3): 删除一个对象

void json_object_object_del(struct json_object* jso, const char *key);

(4): 增加一个对象

void json_object_object_add(struct json_object* jso, const char *key, struct json_object *val);

举例:

json_object_object_add(pobj, "Name", json_object_new_string("Andy"));

json_object_object_add(pobj, "Age", json_object_new_int(200));

(5): 释放对象

void json_object_put(struct json_object *jso);

4:　使用举例

(1): 新建一个x.json文件

{

"item1": "I love JSON",

"foo": "You love Json",

"item3": "We love JSON",

"Name": "Andy",

"Age": 28

}

(2): 程序

#include <stdlib.h>

#include <stdio.h>

#include <unistd.h>

#include <string.h>

#include "json.h"

void GetValByKey(json_object * jobj, const char *sname)

{

json_object *pval = NULL;

enum json_type type;

pval = json_object_object_get(jobj, sname);

if(NULL!=pval){

type = json_object_get_type(pval);

switch(type)

{

case json_type_string:

printf("Key:%s value: %s\n", sname, json_object_get_string(pval));

break;

case json_type_int:

printf("Key:%s value: %d\n", sname, json_object_get_int(pval));

break;

default:

break;

}

}

}

int main(void)

{

json_object *pobj = NULL;

//pobj = json_tokener_parse("{ \"abc\": 12, \"foo\": \"bar\", \"bool0\": false, \"bool1\": true, \"arr\": [ 1, 2, 3, null, 5 ] }");

//printf("new_obj.to_string()=%s\n", json_object_to_json_string(pobj));

//json_parse(pobj);

pobj = json_object_from_file("/home/boy/tmp/test/jsontest/test.json");

GetValByKey(pobj, "foo");

json_object_object_del(pobj, "foo");

json_object_object_add(pobj, "foo", json_object_new_string("fark"));

json_object_object_add(pobj, "Age", json_object_new_int(200));

GetValByKey(pobj, "Age");

json_object_to_file("/home/boy/tmp/test/jsontest/new.json", pobj);

json_object_put(pobj);

return 0;

}

Makefile

all:server

server:

gcc -std=c99 -msse2 -Wall -O3 -o main main.c -ljson -lcrypto -lm -lpthread

完