JSonity is JSON utility for C++
- JSON Parsing and Serializing.
- Serializing User Objects into JSON string.
- Serializing STL (map, vector, list, ...) into JSON string directly.
- Support Unicode (wchar_t, char16_t, char32_t).
- Support I/O stream interface.
- One header file only.
- Simple easy interface.
// If using <std::list, set, deque, array, forward_list, ...>
// Include them before "jsonity.hpp"
//
// #include <list>
// ...
#include "jsonity.hpp"
using namespace jsonity;// example1_1
std::string jsonStr =
"{"
"\"name1\": 100,"
"\"name2\": true,"
"\"name3\": ["
"10,"
"20,"
"30"
"],"
"\"name4\": \"data\""
"}";
Json::Value v;
Json::decode(jsonStr, v); // parse
size_t size = v.getSize(); // 4
bool check = v.hasName("name1"); // true
int n1 = (int)v["name1"].getNumber(); // 100
int n2 = v["name1"]; // 100
bool b1 = v["name2"].getBoolean(); // true
bool b2 = v["name2"]; // true
Json::Array& arr1 = v["name3"].getArray();
Json::Array& arr2 = v["name3"];
size_t array_size = v["name3"].getSize(); // 3
int arr_n1 = arr1[0]; // 10
int arr_n2 = arr1[1]; // 20
int arr_n3 = arr1[2]; // 30
const std::string& str1 = v["name4"].getString(); // "data"
const std::string& str2 = v["name4"]; // "data"
try
{
b1 = v["name4"].getBoolean(); // exception
}
catch (const Json::TypeMismatchException&)
{
// type mismatch
}// example1_2
std::string jsonStr = "{ ... }";
Json::Error err; // error info
Json::Value v;
if (!Json::decode(jsonStr, v, &err)) // parse
{
// error
printf("Index: %d\n",
err.getCursor().getPos() + 1);
printf("Line: %d Col: %d\n",
err.getCursor().getRow() + 1,
err.getCursor().getCol() + 1);
}
// example1_3
std::ifstream ifs("json.dat", std::ios::in | std::ios::binary);
Json::Value v;
Json::decode(ifs, v); // parse// example1_4
std::ifstream ifs("json.dat", std::ios::in | std::ios::binary);
Json::Value v;
ifs >> v; // parse
if (!ifs)
{
// error
}
// example1_5
std::string jsonStr =
"{"
"\"name1\": {"
"\"data1\": ["
"-3.14,"
"\"aaaa\","
"true,"
"{"
"\"subdata1\": ["
"600"
"]"
"}"
"]"
"}"
"}";
Json::Value v;
Json::decode(jsonStr, v); // parse
double d = v["name1"]["data1"][0]; // -3.14
const std::string& str = v["name1"]["data1"][1]; // "aaaa"
bool b = v["name1"]["data1"][2]; // "true"
int n = v["name1"]["data1"][3]["subdata1"][0]; // 600
std::list<Json::Value> listVal;
v.findRecursive("subdata1", listVal); // find recursively
Json::Value& v2 = *listVal.begin();
n = v2[0]; // 600
// example2_1
Json::Object root_obj;
root_obj["name1"] = 100;
root_obj["name2"] = true;
root_obj["name3"] = "data_string";
root_obj["name4"] = Json::null();
Json::Array arr(3);
arr[0] = "test";
arr[1] = -400;
arr[2] = false;
root_obj["name5"] = arr;
Json::Object obj;
obj["xxx"] = -1.5;
obj["yyy"] = true;
obj["zzz"] = "test_test";
root_obj["name6"] = obj;
std::list<int> list; // any STL type (map, vector, list, set, ...)
list.push_back(444);
list.push_back(777);
root_obj["name7"] = list;
std::string jsonStr;
Json::encode(root_obj, jsonStr); // serialize
// jsonStr ==
// {"name1":100,"name2":true,"name3":"data_string","name4":null,
// "name5":["test",-400,false],"name6":{"xxx":-1.5,"yyy":true,"zzz":"test_test"},
// "name7":[444,777]}"// example2_2
Json::Object root_obj;
...
std::ofstream ofs("json.dat",
std::ios::out | std::ios::binary | std::ios::trunc);
Json::encode(root_obj, ofs); // serialize (redirect)// example2_3
Json::Object root_obj;
...
std::cout << root_obj << std::endl; // serialize (redirect)// example2_4
// User Object
class MyData : public Json::UserValue<MyData>
{
public:
MyData(int data1, const std::string& data2)
{
data1_ = data1;
data2_ = data2;
}
MyData(const MyData& other)
{
data1_ = other.data1_;
data2_ = other.data2_;
}
~MyData()
{
}
int getData1() const
{ return data1_; }
const std::string& getData2() const
{ return data2_; }
protected:
// Encode
virtual void encode(Json::EncodeContext& ctx) const
{
std::ostringstream oss;
oss << data2_ << "-" << data1_;
Json::encodeString(ctx, oss.str());
}
private:
int data1_;
std::string data2_;
};
Json::Object root_obj;
// User Object
MyData myData(99, "777");
root_obj["name1"] = myData;
MyData* myDataPtr = new MyData(55, "AAA");
root_obj["name2"] = myDataPtr;
std::string jsonStr;
Json::encode(root_obj, jsonStr); // serialize
// jsonStr == {"name1":"777-99","name2":"AAA-55"}
delete myDataPtr;// example2_5
std::map<std::string, std::string> map; // any STL type (map, vector, list, set, ...)
map["name1"] = "data1";
map["name2"] = "data2";
map["name3"] = "data3";
std::string jsonStr;
Json::encode(map, jsonStr); // serialize
// jsonStr == {"name1":"data1","name2":"data2","name3":"data3"}// example2_6
std::map<std::string, std::list<MyData> > map; // any STL type (map, vector, list, set, ...)
// User Object
std::list<MyData> list;
list.push_back(MyData(66, "666"));
list.push_back(MyData(77, "777"));
list.push_back(MyData(88, "888"));
map["name"] = list;
std::string jsonStr;
Json::encode(map, jsonStr); // serialize
// jsonStr == {"name":["666-66","777-77","888-88"]}// example2_7
std::vector<int> list; // any STL type (map, vector, list, set, ...)
list.push_back(100);
list.push_back(200);
list.push_back(300);
std::string jsonStr;
Json::encode(list, jsonStr); // serialize
// jsonStr == [100,200,300]
// example2_8
std::map<std::string, std::vector<int> > map;
std::vector<int> vec(3);
vec[0] = 100;
vec[1] = 200;
vec[2] = 300;
map["test"] = vec;
Json::EncodeStyle es1;
es1.setStandardStyle();
std::string jsonStr1;
Json::encode(map, jsonStr1, &es1); // serialize (Human Readable)
/* jsonStr1 ==
{
"test": [
100,
200,
300
]
}
*/
Json::EncodeStyle es2;
es2.setQuat(true);
es2.setPrintNewLine(true);
es2.setEscapeCtrlChar(true);
es2.setNewLine(true, false);
std::string jsonStr2;
Json::encode(map, jsonStr2, &es2); // serialize (for C++ Program)
/* jsonStr2 ==
"{\n"
"\"test\": [\n"
"100,\n"
"200,\n"
"300\n"
"]\n"
"}\n"
*/// example3_1
std::string jsonStr =
"{"
"\"aaa\": 100,"
"\"bbb\": \"data\""
"}";
Json::Value v;
Json::decode(jsonStr, v);
bool result = Json::equal(v, jsonStr); // true// example3_2
std::list<int> list;
list.push_back(100);
list.push_back(200);
list.push_back(300);
bool result1 = Json::equal(list, "[ 100, 200, 300 ]"); // true
bool result2 = Json::equal(list, "[ 300, 100, 200 ]"); // true
bool result3 = Json::equal(list, "[ 300, 100, 200 ]", false); // false