jsoncpp的安装与使用示例

安装：

生成静态库

 生成静态库:
 第一步:生成目标文件:
 g++ -g -Wall -c json_reader.cpp json_value.cpp json_writer.cpp -I. -I../../include -lpthread
 
 会生成三个*.o文件
  json_reader.o
 json_value.o
 json_writer.o
 
 第二步:生成静态库文件:
 ar rcs libjsoncpp.a *.o

生成动态库:

g++ -g json_reader.cpp json_value.cpp json_writer.cpp -fPIC -Wall -shared -o libjsoncpp.so -I. -I../../include -lpthread

记得引用时:

1.指定库文件:比如将生成的 libjsoncpp.so和libjsoncpp.a库文件放到/usr/local/lib/jsoncpp-src-0.5.0/下面.

2.指定头文件位置:比如,将jsoncpp-src-0.5.0/include/下的头文件放到/usr/local/include/jsoncpp-src-0.5.0/下面.

实用示例：

 #include <iostream>
 #include <fstream>
 
 //#include </usr/local/include/jsoncpp0.5.0/json/json.h>
 //#include <json/json.h>
 #include <json/json.h>
 using namespace std;
 
 int main()
 {
     //根节点
     Json::Value root;
 
     //根节点属性
     root["name"] = Json::Value("Tsybius");
     root["age"] = Json::Value();
     root["sex_is_male"] = Json::Value(true);
 
     //子节点
     Json::Value partner;
 
     //子节点属性
     partner["partner_name"] = Json::Value("Galatea");
     partner["partner_age"] = Json::Value();
     partner["partner_sex_is_male"] = Json::Value(false);
 
     //子节点挂到根节点上
     root["partner"] = Json::Value(partner);
 
     //数组形式
     root["achievement"].append("ach1");
     root["achievement"].append("ach2");
     root["achievement"].append("ach3");
 
     //直接输出
     cout << "FastWriter:" << endl;
     Json::FastWriter fw;
     cout << fw.write(root) << endl << endl;
 
     //缩进输出
     cout << "StyledWriter:" << endl;
     Json::StyledWriter sw;
     cout << sw.write(root) << endl << endl;
 
     //输出到文件
     ofstream os;
     os.open("./PersonalInfo.js");
     os << sw.write(root);
     os.close();
 
     return ;
 }

output:

FastWriter:
{"achievement":["ach1","ach2","ach3"],"age":,"name":"Tsybius","partner":{"partner_age":,"partner_name":"Galatea","partner_sex_is_male":false},"sex_is_male":true}
 
StyledWriter:
{
   "achievement" : [ "ach1", "ach2", "ach3" ],
   "age" : ,
   "name" : "Tsybius",
   "partner" : {
      "partner_age" : ,
      "partner_name" : "Galatea",
      "partner_sex_is_male" : false
   },
   "sex_is_male" : true
}

 #include <bits/stdc++.h>
 //#include <json/json.h>
 #include </usr/include/jsoncpp/json/json.h>
 void readJson();
 void writeJson();
 
 int main(int argc, char **argv)
 {
     readJson();
     writeJson();
     return ;
 }
 
 void readJson()
 {
     using namespace std;
     std::string strValue =
         "{\"name\":\"json\",\"array\":[{\"cpp\":\"jsoncpp\"},{\"java\":\"jsoninjava\"},{\"php\":\"support\"}]}";
 
     Json::Reader reader;
     Json::Value value;
 
     if (reader.parse(strValue, value)) {
         std::string out = value["name"].asString();
         std::cout << out << std::endl;
         const Json::Value arrayObj = value["array"];
         for (unsigned int i = ; i < arrayObj.size(); i++) {
             if (!arrayObj[i].isMember("cpp"))
                 continue;
             out = arrayObj[i]["cpp"].asString();
             std::cout << out;
             if (i != (arrayObj.size() - ))
                 std::cout << std::endl;
         }
     }
 }
 
 void writeJson()
 {
     using namespace std;
 
     Json::Value root;
     Json::Value arrayObj;
     Json::Value item;
 
     item["cpp"] = "jsoncpp";
     item["java"] = "jsoninjava";
     item["php"] = "support";
     arrayObj.append(item);
 
     root["name"] = "json";
     root["array"] = arrayObj;
 
     root.toStyledString();
     std::string out = root.toStyledString();
     std::cout << out << std::endl;
 }

 json
 jsoncpp
 {
    "array" : [
       {
          "cpp" : "jsoncpp",
          "java" : "jsoninjava",
          "php" : "support"
       }
    ],
    "name" : "json"
 }