c++ json封装---解析

来源：互联网发布：asp sql防注入代码编辑：程序博客网时间：2024/06/06 10:53

首先要有编译的json库

#pragma once

#include <json.h>

using namespace Json;
using namespace std;
class CParseJson
{
public:
   CParseJson();
   bool ParseJson(const string& _sJson);
   bool GetString(const string& _sKey, string& _sValue);
   bool GetInt(const string& _sKey, int& _iValue);
   bool GetBool(const string& _sKey, bool& _bValue);
   bool GetDouble(const string& _sKey, double& _dValue);
   bool GetArray(const string& _sKey, Value& _aryValue);
   bool GetObject(const string& _sKey, Value& _objValue);
   const char* GetLastError();
private:
   bool _GetValue(const string& _sKey, int _iType, Value& _Value);
private:
   /**
     * @brief The Type enum
     * 是字段类型枚举
     */
    enum Type {
        Int = 0x0,///整型
        Bool = 0x1,///<bool值
        Double = 0x2,///<浮点型
        String = 0x3,///<字符串
        Array = 0x4,///<json数组
        Object = 0x5,///<json对象
        Undefined = 0x80///<无定义
    };
   Value m_jsonObj; ///<解析后的json对象
   string m_sError;   ///<解析过程出现的错误信息
   bool m_bSucceess; ///<解析是否成功标志位

};

#include "OprJson.h"

#include <sstream>

CParseJson::CParseJson()
:m_bSucceess(false)
{

}
bool CParseJson::ParseJson(const string& _sJson)
{
   Reader reader;
   if (false == (m_bSucceess = reader.parse(_sJson, m_jsonObj)))
   {
       m_sError = reader.getFormatedErrorMessages();
   }
   return m_bSucceess;
}

bool CParseJson::GetString(const string& _sKey, string& _sValue)
{
   Value value;
   if (_GetValue(_sKey, String, value))
   {
       _sValue = value.asString();
       return true;
   }
   return false;
}

bool CParseJson::GetInt(const string& _sKey, int& _iValue)
{
   Value value;
   if (_GetValue(_sKey, Int, value))
   {
       _iValue = value.asInt();
       return true;
   }
   return false;
}

bool CParseJson::GetBool(const string& _sKey, bool& _bValue)
{
   Value value;
   if (_GetValue(_sKey, Bool, value))
   {
       _bValue = value.asBool();
       return true;
   }
   return false;
}

bool CParseJson::GetDouble(const string& _sKey, double& _dValue)
{
   Value value;
   if (_GetValue(_sKey, Double, value))
   {
       _dValue = value.asDouble();
       return true;
   }
   return false;
}

bool CParseJson::GetArray(const string& _sKey, Value& _aryValue)
{
   return _GetValue(_sKey, Array, _aryValue);
}

bool CParseJson::GetObject(const string& _sKey, Value& _objValue)
{
   return _GetValue(_sKey, Object, _objValue);
}

const char* CParseJson::GetLastError()
{
   return m_sError.c_str();
}

bool CParseJson::_GetValue(const string& _sKey, int _iType, Value& _Value)
{
   if (false == m_bSucceess)
   {
       return false;
   }
   if (false == m_jsonObj.isMember(_sKey))
   {
       ostringstream stream;
       stream << "json object not found key:" << _sKey;
       m_sError = stream.str();
       return false;
   }
   _Value = m_jsonObj[_sKey];
   string sErrorType;
   bool bType = false; //类型是否正确
   switch (_iType)
   {
   case Int:
       if (false == (bType = _Value.isInt()))
       {
           sErrorType = "Int";
       }
       break;
   case String:
       if (false == (bType = _Value.isString()))
       {
           sErrorType = "String";
       }
       break;
   case Bool:
       if (false == (bType = _Value.isBool()))
       {
           sErrorType = "Bool";
       }
       break;
   case Double:
       if (false == (bType = _Value.isDouble()))
       {
           sErrorType = "Double";
       }
       break;
   case Array:
       if (false == (bType = _Value.isArray()))
       {
           sErrorType = "Array";
       }
       break;
   case Object:
       if (false == (bType = _Value.isObject()))
       {
           sErrorType = "Object";
       }
       break;
   default:
       bType = false;
       break;
   }
   if (false == bType)
   {
       ostringstream stream;
       stream << "the key:" << _sKey << " is not " << sErrorType << " type";
       m_sError = stream.str();
   }
   return bType;
}

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