利用 jsoncpp 读取数组和对象例子

迷南。 2023-06-28 11:29 130阅读 0赞

/*
    test1.json文件 [数组]
    [
     [2.0,5.6],
     [5.2,9.6]
    ]
    
    
    */
    
    /*
    test2.json文件  [对象]
    {
    	"backupIP": "localhost",
    	"code": 0,
    	"discovery": "http://127.0.0.1/api",
    	"port": "8000",
    	"priorIP": "127.0.0.1"
    }
    
    */
    
    #include "stdafx.h"
    #include <iostream>
    #include <fstream>
    #include "jsoncpp\json\json.h"
    using namespace std;
    
    //读取文件中的对象
    bool readFileJsonObj(const char *_Filename)
    {
    	if (_Filename == NULL)
    	{
    		std::cout << "_Filename || pSampledata == null erro!\n";
    		return false;
    	}
    
    	Json::Reader reader;
    	Json::Value root;
    
    	//从文件中读取，保证当前文件有data.json文件
    	std::ifstream in(_Filename, ios::binary);
    
    	if( !in.is_open() )  
    	{ 
    		std::cout << "Error open: " <<_Filename<<std::endl; 
    		return false; 
    	}
    
    	/*
    
    	{
    	"backupIP": "localhost",
    	"code": 0,
    	"discovery": "http://127.0.0.1/api",
    	"port": "8000",
    	"priorIP": "127.0.0.1"
    	}
    
    	*/
    	if(reader.parse(in,root))
    	{
    
    		int nCode = root.get("code", "").asInt();
    		std::cout<<nCode<<" , ";
    		std::cout<<root.get("priorIP", "").asString()<<" , ";
    		std::cout<<	root.get("backupIP", "").asString()<<" , ";
    		std::cout<<root.get("port", "").asString()<<" , ";
    		std::cout<<root.get("discovery", "").asString()<<std::endl;
    
    
    	}
    	in.close();
    	return true;
    }
    
    //从文件中读取JSON  数组
    bool readFileJson(const char *_Filename)
    {
    	if (_Filename == NULL)
    	{
    		std::cout << "_Filename || pSampledata == null erro!\n";
    		return false;
    	}
    
    	Json::Reader reader;
    	Json::Value root;
    
    	//从文件中读取，保证当前文件有data.json文件
    	std::ifstream in(_Filename, ios::binary);
    
    	if( !in.is_open() )  
    	{ 
    		std::cout << "Error open: " <<_Filename<<std::endl; 
    		return false; 
    	}
    
    	/*
    	json
    	[
    	[2.0,5.6],
    	[5.2,9.6]
    	]
    
    	*/
    
    	int nTatolSize = 0;
    	if(reader.parse(in,root))
    	{
    
    		int ns = root.size();
    		//读取数组信息
    		for(unsigned int i = 0; i < ns; i++)
    		{
    			Json::Value tmp = root[i];
    			nTatolSize += tmp.size();  
    
    		}
    		std::cout<<"nTatolSize : "<<nTatolSize <<"\n";
    		for(unsigned int i = 0; i < ns; i++)
    		{
    			Json::Value tmp = root[i];
    			int image_size = tmp.size();  
    
    			for(int j = 0; j < image_size; ++j)  
    			{  
    				float fvalue= tmp[j].asFloat(); 
    				std::cout<<"value : "<<fvalue <<" , ";
    			} 
    			std::cout<<"\n";
    		}
    
    	}
    	in.close();
    	return true;
    }
    
    int _tmain(int argc, _TCHAR* argv[])
    {
    	readFileJson("test1.json");
    	readFileJsonObj("test2.json");
    	return 0;
    }