ARM平台移植 json-c-0.12

系统环境：Ubuntu 14.04.3 LTS

源码：json-c-0.12.tar.gz

交叉编译环境：arm-none-linux-gnueabi-

[zhaojq@virtual-machine]# tar -xzvf json-c-0.12.tar.gz

[zhaojq@virtual-machine]# cd json-c-0.12

[zhaojq@virtual-machine]# ./configure CC= arm-none-linux-gnueabi-gcc
--host=arm-none-linux-gnueabi --build=i686-linux-gnu

手动修改config.h.in，注释掉下面两行

//#undef malloc

//#undef realloc

不然在编译test实例时会出现undefined reference to “rpl_malloc”和undefined
reference to “rpl_realloc”两处未定义错误

[zhaojq@virtual-machine]# libtoolize
--version

[zhaojq@virtual-machine]# autoheader
--version

查看通用库是否存在，不存在则安装通用库：

[zhaojq@virtual-machine]# apt-get
install libtool

[zhaojq@virtual-machine]# apt-get
install autoconf

不然在make时会出现json-c-0.12/missing: line 81: autoheader: command not found等错误

[zhaojq@virtual-machine]# sudo
-i

切换到root状态下

不然在make时会出现line 1086: arm-none-linux-gnueabi-ranlib:
command not found等错误

[root@virtual-machine]# make

[root@virtual-machine]# make
install

安装成功

json头文件在/usr/local/include/json目录

[zhaojq@virtual-machine /usr/local/include/json-c]# ls

arraylist.h json_config.h json_inttypes.h json_object_private.h linkhash.h

bits.h json_c_version.h json_object.h json_tokener.h printbuf.h

debug.h json.h json_object_iterator.h json_util.h random_seed.h

交叉编译后的动态库文件在/usr/local/lib目录
[zhaojq@virtual-machine /usr/local/lib]# ls

libjson-c.a libjson-c.so libjson-c.so.2.0.1

libjson-c.la libjson-c.so.2 pkgconfig

编译test实例

[zhaojq@virtual-machine]#
vim json_test.cpp

#include <stdio.h>
#include "json.h"

int main(int argc, char *argv[])
{
struct json_object *infor_object = NULL;
infor_object = json_object_new_object();
if (NULL == infor_object)
{
printf("new json object failed.\n");
return 0;
}

struct json_object *para_object = NULL;
para_object = json_object_new_object();
if (NULL == para_object)
{
json_object_put(infor_object);
printf("new json object failed.\n");
return 0;
}

struct json_object *array_object = NULL;
array_object = json_object_new_array();
if (NULL == array_object)
{
json_object_put(infor_object);//free
json_object_put(para_object);//free
printf("new json object failed.\n");
return 0;
}

/*添加json值类型到数组中*/
json_object_array_add(array_object, json_object_new_int(256));
json_object_array_add(array_object, json_object_new_int(257));
json_object_array_add(array_object, json_object_new_int(258));

/*添加json名称和值到json对象集合中*/
json_object_object_add(para_object, "DeviceId", json_object_new_string("sn_iso_9000"));
json_object_object_add(para_object, "MacAddr", json_object_new_string("AA:BB:CC:DD:EE:FF"));
json_object_object_add(para_object, "Visible", json_object_new_int(1));

json_object_object_add(infor_object, "method", json_object_new_string("GetSystemInfo"));
json_object_object_add(infor_object, "param", para_object);
json_object_object_add(infor_object, "id", json_object_new_string("101"));

/*添加数组集合到json对象中*/
json_object_object_add(infor_object, "array", array_object);

printf("-----------json infor ---------------------------\n");
printf("%s\n", json_object_to_json_string(infor_object));
printf("-----------json infor ---------------------------\n");

struct json_object *result_object = NULL;
json_object_object_get_ex(infor_object, "method", &result_object);
printf("method = %s\n", json_object_to_json_string(result_object));

json_object_object_get_ex(infor_object, "param", &result_object);
printf("param = %s\n", json_object_to_json_string(result_object));

json_object_object_get_ex(infor_object, "array", &result_object);
printf("array = %s\n", json_object_to_json_string(result_object));
int i;
for(i = 0; i < json_object_array_length(result_object); i++)
{
struct json_object *obj = json_object_array_get_idx(result_object, i);
printf("\t[%d]=%s\n", i, json_object_to_json_string(obj));
}

json_object_put(infor_object);//free
return 0;
}

注：

json-c-0.12版本不能使用json_object_object_get函数，会出现如下warning

warning: 'json_object* json_object_object_get(json_object*, const char*)' is deprecated (declared at /usr/local/include/json-c/json_object.h:290)

所以使用json_object_object_get_ex函数

[zhaojq@virtual-machine]# arm-none-linux-gnueabi-g++
-ljson-c -I/usr/local/include/json-c/ -L/usr/local/lib -o json_test json_test.cpp

编译通过，在当前目录生成json_test可执行文件

将/usr/local/lib目录下得libjson.*和pkgconfig目录都拷贝到ARM设备上文件系统的/lib目录，

将json_test拷贝到ARM设备上

执行./json_test

输出：

-----------json infor ---------------------------

{ "method": "GetSystemInfo", "param": { "DeviceId": "sn_iso_9000", "MacAddr": "AA:BB:CC:DD:EE:FF", "Visible": 1 }, "id": "101", "array": [ 256, 257, 258 ] }

-----------json infor ---------------------------

method = "GetSystemInfo"

param = { "DeviceId": "sn_iso_9000", "MacAddr": "AA:BB:CC:DD:EE:FF", "Visible": 1 }

array = [ 256, 257, 258 ]

[0]=256

[1]=257

[2]=258

移植成功。