c++解析json文件: Rapidjson

json文件用來當配置文件很好用，很輕便。但是試過好幾個c++的json庫，有些編譯特別麻煩。

Rapidjson的使用很簡單，添加幾個頭文件就行了，而且跨平臺，速度快。

JSON文件：

[
	{ 
		"bank_name" : "BOA",
    	"chain_num":123, 
    	"servers":[
    		{
    			"ip" : "127.0.0.1",
    			"port" : 1111
    		},
    		{
    			"ip" : "127.0.0.1",
    			"port" : 2222
    		}
    	] 
	},

	{ 
		"bank_name" : "CITIBANK",
    	"chain_num":789, 
    	"servers":[
    		{
    			"ip" : "127.0.0.1",
    			"port" : 3333
    		},
    		{
    			"ip" : "127.0.0.1",
    			"port" : 4444
    		}
    	]
	}
]

解析代碼：

#include "rapidjson/document.h"
#include "rapidjson/prettywriter.h"
#include "rapidjson/filestream.h" 
#include <cstdio>
#include <iostream>
#include <string>

using namespace rapidjson;
using namespace std;

int main()
{
    FILE *fp = fopen("t2.json", "r");
    FileStream is(fp);

    Document bank;
    bank.ParseStream<0>(is);

    if (bank.HasParseError())
    {
        printf("GetParseError %s\n", bank.GetParseError());
    }

    for (unsigned int i = 0; i < bank.Size(); ++i)
    {
        const Value & cur_bank = bank[i];
        cout <<"BANK # "<< i+1 <<endl;
        cout <<"bank_name: "<<cur_bank["bank_name"].GetString() << endl;
        cout <<"chain_num: " <<cur_bank["chain_num"].GetInt() << endl;

        Value & server_array = bank[i]["servers"];

        for (unsigned int j = 0; j < server_array.Size(); ++j)
        {
            cout <<"IP: "<<server_array[j]["ip"].GetString() << " ";          
            cout <<"PORT: "<<server_array[j]["port"].GetInt() << " ";
            cout <<endl;
        }
        cout <<endl;

    }
    return 0;
}