jansson 库测试

#include
#include
#include

#define FILE_PATH         "./temp.txt"
#define MAX_NUM            5

typedef struct _JSON_ITEM_INFO
{
	json_t* string;
	json_t* value;
	json_t* string2;
}JSON_ITEM_INFO;


void save_info_to_file()
{
	json_t* root   = NULL;
	json_t* item_1 = NULL;
	json_t* item_2 = NULL;
	json_t* item_3 = NULL;
	json_t* array  = NULL;

	char* s_repon = NULL;

	root   = json_object();
	item_1 = json_object();
	item_2 = json_object();
	item_3 = json_object();
	array  = json_array();

	json_object_set_new(item_1, "name", json_string("xiaopeng"));
	json_object_set_new(item_1, "age", json_integer(12));
	json_object_set_new(item_1, "area", json_string("shanghai"));
	json_array_append_new(array, item_1);

	json_object_set_new(item_2, "name", json_string("xiaoming"));
	json_object_set_new(item_2, "age", json_integer(8));
	json_object_set_new(item_2, "area", json_string("HK"));
	json_array_append_new(array, item_2);

	json_object_set_new(item_3, "name", json_string("xiaohong"));
	json_object_set_new(item_3, "age", json_integer(22));
	json_object_set_new(item_3, "area", json_string("Fujian"));
	json_array_append_new(array, item_3);

	json_object_set_new(root, "root", array);

	json_dump_file(root, FILE_PATH, JSON_PRESERVE_ORDER);
	printf("写入完成\n");

	s_repon = json_dumps(root, JSON_INDENT(0));

	printf("s_repon = %s \n", s_repon);
	printf("打印完成\n");
	free(s_repon);

	printf("size = %d \n", (int)json_array_size(array));
	printf("数组个数\n");

	if (root)
	{
		json_delete(root);
	}
	if (array)
	{
		json_delete(array);
	}
}

void get_file_info()
{
	int i = 0;

	json_t* root = NULL;
	json_t* array = NULL;
	json_error_t error;
	char* s_repon = NULL;

	json_t* add_item_1 = NULL;
	char* s_get_add_item = NULL;

	json_t* rec_table[MAX_NUM] = { 0 };

	JSON_ITEM_INFO person[MAX_NUM];
	memset(person, 0, sizeof(person));

	//get the info from file;
	root = json_load_file(FILE_PATH, 0, &error);
	if (!json_is_object(root))
	{
		printf("%s,%d\n", __FILE__, __LINE__);
	}
	s_repon = json_dumps(root, JSON_INDENT(0));
	printf("s_repon = %s \n", s_repon);
	printf("读取完成\n");
	free(s_repon);

	array = json_object_get(root, "root");
	if (!json_is_array(array))
	{
		printf("%s,%d\n", __FILE__, __LINE__);
	}

	for (i = 0; i < (int)json_array_size(array); i++)
	{
		rec_table[i] = json_array_get(array, i);
		if (!json_is_object(rec_table[i]))
		{
			printf("%s,%d\n", __FILE__, __LINE__);
		}
		person[i].string = json_object_get(rec_table[i], "name");
		printf("person[%d].string = %s \n", i, json_string_value(person[i].string));
		person[i].value = json_object_get(rec_table[i], "age");
		printf("person[%d].value = %d \n", i, (int)json_integer_value(person[i].value));
		person[i].string2 = json_object_get(rec_table[i], "area");
		printf("person[%d].area = %s \n", i, json_string_value(person[i].string2));
	}
	printf("打印完成\n");
	//add the new item;
	add_item_1 = json_object();
	json_object_set_new(add_item_1, "name", json_string("zhangsan"));
	json_object_set_new(add_item_1, "age", json_integer(30));

	if (json_array_size(array) >= MAX_NUM)
	{
		//remove the top item;
		json_array_remove(array, 0);

	}
	json_array_append_new(array, add_item_1);

	//write the new array to the file;
	json_dump_file(root, FILE_PATH, JSON_PRESERVE_ORDER);

	//dump the date and print
	s_get_add_item = json_dumps(root, JSON_INDENT(0));

	printf("s_get_add_item = %s \n", s_get_add_item);
	free(s_get_add_item);

}

int main()
{
	save_info_to_file(); //这里将数据保存在文件 FILE_PATH 里；
	get_file_info();     // 这里将文件 FILE_PATH 数据读取出来；
	system("pause");

	return 0;
}

输出为：

 

加层之后：

#include
#include
#include

#define FILE_PATH         "./temp.txt"
#define MAX_NUM            5

typedef struct _JSON_ITEM_INFO
{
	json_t* string;
	json_t* value;
	json_t* string2;
}JSON_ITEM_INFO;


void save_info_to_file()
{
	json_t* root_1 = NULL;
	json_t* root_2 = NULL;
	json_t* item_1 = NULL;
	json_t* item_2 = NULL;
	json_t* item_3 = NULL;
	json_t* array  = NULL;
	json_t* array2 = NULL;
	json_t* root   = NULL;

	char* s_repon = NULL;

	root_1 = json_object();
	root_2 = json_object();
	item_1 = json_object();
	item_2 = json_object();
	item_3 = json_object();
	root   = json_object();
	array  = json_array();
	array2 = json_array();
	

	json_object_set_new(item_1, "name", json_string("xiaopeng"));
	json_object_set_new(item_1, "age", json_integer(12));
	json_object_set_new(item_1, "area", json_string("shanghai"));
	json_array_append_new(array, item_1);

	json_object_set_new(item_2, "name", json_string("xiaoming"));
	json_object_set_new(item_2, "age", json_integer(8));
	json_object_set_new(item_2, "area", json_string("HK"));
	json_array_append_new(array, item_2);

	json_object_set_new(item_3, "name", json_string("xiaohong"));
	json_object_set_new(item_3, "age", json_integer(22));
	json_object_set_new(item_3, "area", json_string("Fujian"));
	json_array_append_new(array, item_3);

	json_object_set_new(root_1, "root_1", array);
	json_object_set_new(root_2, "root_2", array);
	json_array_append_new(array2, root_1);
	json_array_append_new(array2, root_2);
	json_object_set_new(root, "root", array2);



	json_dump_file(root, FILE_PATH, JSON_PRESERVE_ORDER);
	printf("写入完成\n");

	s_repon = json_dumps(root, JSON_INDENT(0));

	printf("s_repon = %s \n", s_repon);
	printf("打印完成\n");
	free(s_repon);

	printf("size = %d \n", (int)json_array_size(array));
	printf("数组个数\n");

	if (array)
	{
		json_delete(array);
	}
	if (array2)
	{
		json_delete(array2);
	}
	if (root)
	{
		json_delete(root);
	}
}

void get_file_info()
{
	int i = 0;

	json_t* root_1  = NULL;
	json_t* root_2  = NULL;
	json_t* root    = NULL;
	json_t* array   = NULL;
	json_t* array2  = NULL;
	json_error_t error;
	char* s_repon = NULL;

	json_t* add_item_1   = NULL;
	char* s_get_add_item = NULL;

	json_t* rec_table[MAX_NUM] = { 0 };

	JSON_ITEM_INFO person[MAX_NUM];
	memset(person, 0, sizeof(person));

	//get the info from file;
	root = json_load_file(FILE_PATH, 0, &error);
	if (!json_is_object(root))
	{
		printf("%s,%d\n", __FILE__, __LINE__);
	}
	s_repon = json_dumps(root, JSON_INDENT(0));
	printf("s_repon = %s \n", s_repon);
	printf("读取完成\n");
	free(s_repon);

	array2 = json_object_get(root, "root");
	root_1 = json_array_get(array2, 0);
	array = json_object_get(root_1, "root_1");
	
	if (!json_is_array(array))
	{
		printf("%s,%d\n", __FILE__, __LINE__);
		printf("array不是数组\n");
	}
	printf("开始读取输出内容\n");
	
	for (i = 0; i < (int)json_array_size(array); i++)
	{
		rec_table[i] = json_array_get(array, i);
		if (!json_is_object(rec_table[i]))
		{
			printf("%s,%d\n", __FILE__, __LINE__);
		}
		person[i].string = json_object_get(rec_table[i], "name");
		printf("person[%d].string = %s \n", i, json_string_value(person[i].string));
		person[i].value = json_object_get(rec_table[i], "age");
		printf("person[%d].value = %d \n", i, (int)json_integer_value(person[i].value));
		person[i].string2 = json_object_get(rec_table[i], "area");
		printf("person[%d].area = %s \n", i, json_string_value(person[i].string2));
	}
	printf("打印完成\n");
	//add the new item;
	add_item_1 = json_object();
	json_object_set_new(add_item_1, "name", json_string("zhangsan"));
	json_object_set_new(add_item_1, "age", json_integer(30));
	json_object_set_new(add_item_1, "area", json_string("Shandong"));

	if (json_array_size(array) >= MAX_NUM)
	{
		//remove the top item;
		json_array_remove(array, 0);

	}
	json_array_append_new(array, add_item_1);

	//write the new array to the file;
	json_dump_file(root, FILE_PATH, JSON_PRESERVE_ORDER);

	//dump the date and print
	s_get_add_item = json_dumps(root, JSON_INDENT(0));
	printf("添加完成\n");
	
	printf("s_get_add_item = %s \n", s_get_add_item);
	free(s_get_add_item);

}

int main()
{
	save_info_to_file(); //这里将数据保存在文件 FILE_PATH 里；
	get_file_info();     // 这里将文件 FILE_PATH 数据读取出来；
	system("pause");

	return 0;
}

输出为：