jsoncpp封装和解析字符串、数字、布尔值和数组

unzip jsoncpp.rar

vim src/main.cpp

  1 #include <string>
  2 #include <json/json.h>
  3 #include "stdio.h"
  4 
  5 int ReadJson(const std::string &);
  6 std::string writeJson();
  7 
  8 int main(int argc, char** argv)
  9 {
 10     using namespace std;
 11 
 12     std::string strMsg;
 13 
 14     cout<<"--------------------------------"<<endl;
 15     strMsg = writeJson();
 16     cout<< "json write : " << endl << strMsg << endl;
 17     cout<<"--------------------------------"<<endl;
 18     cout<< "json read :" << endl;
 19     ReadJson(strMsg);
 20     cout<<"--------------------------------"<<endl;
 21 
 22     return 0;
 23 }
 24 
 25 int ReadJson(const std::string & strValue) 
 26 {
 27     using namespace std;
 28 
 29     Json::Reader reader;
 30     Json::Value value;
 31 
 32     if (reader.parse(strValue, value))
 33     {
 34         //解析json中的对象
 35         string out = value["name"].asString();
 36         cout << "name : "   << out << endl;
 37         cout << "number : " << value["number"].asInt() << endl;
 38         cout << "value : "  << value["value"].asBool() << endl;
 39         cout << "no such num : " << value["haha"].asInt() << endl;
 40         cout << "no such str : " << value["hehe"].asString() << endl;
 41 
 42         //解析数组对象
 43         const Json::Value arrayNum = value["arrnum"];
 44         for (unsigned int i = 0; i < arrayNum.size(); i++)
 45         {
 46             cout << "arrnum[" << i << "] = " << arrayNum[i];
 47         }
 48         //解析对象数组对象
 49         Json::Value arrayObj = value["array"];
 50         cout << "array size = " << arrayObj.size() << endl;
 51         for(unsigned int i = 0; i < arrayObj.size(); i++)
 52         {
 53             cout << arrayObj[i];
 54         }
 55         //从对象数组中找到想要的对象
 56         for(unsigned int i = 0; i < arrayObj.size(); i++)
 57         {
 58             if (arrayObj[i].isMember("string")) 
 59             {
 60                 out = arrayObj[i]["string"].asString();
 61                 std::cout << "string : " << out << std::endl;
 62             }
 63         }
 64     }
 65 
 66     return 0;
 67 }
 68 
 69 std::string writeJson() 
 70 {
 71     using namespace std;
 72 
 73     Json::Value root;
 74     Json::Value arrayObj;
 75     Json::Value item;
 76     Json::Value iNum;
 77 
 78     item["string"]    = "this is a string";
 79     item["number"]    = 999;
 80     item["aaaaaa"]    = "bbbbbb";
 81     arrayObj.append(item);
 82 
 83     //直接对jsoncpp对象以数字索引作为下标进行赋值，则自动作为数组
 84     iNum[1] = 1;
 85     iNum[2] = 2;
 86     iNum[3] = 3;
 87     iNum[4] = 4;
 88     iNum[5] = 5;
 89     iNum[6] = 6;
 90 
 91     //增加对象数组
 92     root["array"]    = arrayObj;
 93     //增加字符串
 94     root["name"]    = "json";
 95     //增加数字
 96     root["number"]    = 666;
 97     //增加布尔变量
 98     root["value"]    = true;
 99     //增加数字数组
100     root["arrnum"]    = iNum;
101 
102     root.toStyledString();
103     string out = root.toStyledString();
104 
105     return out;
106 }

jsoncpp$ make
mkdir -p objs/src/json;  mkdir -p objs/src;
g++ -c -Wall -Werror -g -I include src/json/json_reader.cpp -o objs/src/json/json_reader.o
g++ -c -Wall -Werror -g -I include src/json/json_value.cpp -o objs/src/json/json_value.o
g++ -c -Wall -Werror -g -I include src/json/json_writer.cpp -o objs/src/json/json_writer.o
g++ -c -Wall -Werror -g -I include src/main.cpp -o objs/src/main.o
g++  objs/src/json/json_reader.o objs/src/json/json_value.o objs/src/json/json_writer.o objs/src/main.o -o main

./main

fengbo: jsoncpp$ ./main 
--------------------------------
json write : 
{
   "array" : [
      {
         "aaaaaa" : "bbbbbb",
         "number" : 999,
         "string" : "this is a string"
      }
   ],
   "arrnum" : [ null, 1, 2, 3, 4, 5, 6 ],
   "name" : "json",
   "number" : 666,
   "value" : true
}

--------------------------------
json read :
name : json
number : 666
value : 1
no such num : 0
no such str : 
arrnum[0] = null
arrnum[1] = 1
arrnum[2] = 2
arrnum[3] = 3
arrnum[4] = 4
arrnum[5] = 5
arrnum[6] = 6
array size = 1

{
    "aaaaaa" : "bbbbbb",
    "number" : 999,
    "string" : "this is a string"
}
string : this is a string
--------------------------------