在此站点下载jsoncpp(https://sourceforge.net/projects/jsoncpp/这个站点的版本较旧)
在电脑上安装Python,运行amalgamate.py,生成的dist目录中包含了我们需要的源文件和头文件
以下是使用jsoncpp解析与生成json的示例代码,
其中json_text.txt的内容为(关于此json数据的来源可参考此站点)
{ "face": [ { "attribute": { "age":27, "gender":"Male", "lefteye_opendegree":43, "mouth_opendegree":2, "pose": { "raise":-21, "tilting":-2, "turn":4 }, "righteye_opendegree":47 }, "face_id":"83e3edac3d5d49579089d3ee043d41ec", "position": { "center":{"x":179,"y":50}, "eye_left":{"x":206,"y":78}, "eye_right":{"x":248,"y":78}, "height":94,"width":94 }, "tag":"" } ], "img_height":500, "img_id":"030-3aff983ea4ea5a35f89ae6", "img_width":350, "res_code":"0000", "url":"http://e.hiphotos.baidu.com/baike/pic/item/9345d688d43f879428d347b3d81b0ef41bd53a7a.jpg" }
jsoncpp_parse_test.cpp
#include <iostream> #include <fstream> #include "jsoncpp/json.h" int main() { using namespace std; using namespace Json; ifstream ifs("json_text.txt"); if (ifs) { string line, jsonStr; while (getline(ifs, line)) jsonStr.append(line); CharReader *reader = CharReaderBuilder().newCharReader(); Value root; JSONCPP_STRING errs; if (reader->parse(jsonStr.c_str(), jsonStr.c_str() + jsonStr.size(), &root, &errs)) { auto faceId = root["face"][0]["face_id"].asString(); auto imgWidth = root["img_width"].asInt(); auto imgHeight = root["img_height"].asInt(); auto resCode = root["res_code"].asString(); auto url = root["url"].asString(); cout << "face_id: " << faceId << endl; cout << "img_ " << imgWidth << endl; cout << "img_height: " << imgHeight << endl; cout << "res_code: " << resCode << endl; cout << "url: " << url << endl; } else cout << errs << endl; delete reader; } return 0; }
jsoncpp_generate_test.cpp
#include <iostream> #include <memory> #include "jsoncpp/json.h" int main() { std::unique_ptr<Json::StreamWriter> writer(Json::StreamWriterBuilder().newStreamWriter()); Json::Value array, element; element["face_id"] = "a9cebf8d5ae6fff514d8d2d8e07fa55b"; element["similarity"] = 100; element["img_id"] = "12.jpg"; element["people_name"] = "张艺谋"; array["result"].append(element); element["face_id"] = "7f2de0e85bede3171c839d0dcabd849f"; element["similarity"] = 55.379097; element["img_id"] = "6.jpg"; element["people_name"] = "曾国藩"; array["result"].append(element); element["face_id"] = "40ebb31e8af7237a73dec9f242885a7e"; element["similarity"] = 52.59766; element["img_id"] = "2.jpg"; element["people_name"] = "测试"; array["result"].append(element); //std::ostringstream ss; if (writer->write(array, &std::cout)) std::cout << "write failed" << std::endl; else std::cout << std::endl; return 0; }
Compile.bat
g++ -std=c++11 jsoncpp_parse_test.cpp jsoncpp/jsoncpp.cpp -o jsoncpp_parse_test g++ -std=c++11 jsoncpp_generate_test.cpp jsoncpp/jsoncpp.cpp -o jsoncpp_generate_test