我们知道json串的格式， 那么组装json不就很容易吗？ 恩， 但是， 如果我们自己组装， 遇到特殊字符会有坑， 而且， 代码看起来恶心， 不信？ 来看看：

#include <iostream>
#include <stdio.h>
#include<unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include<sstream>

// 请自己下载开源的rapidjson
#include "rapidjson/prettywriter.h"
#include "rapidjson/rapidjson.h"
#include "rapidjson/document.h"
#include "rapidjson/stringbuffer.h"
#include "rapidjson/writer.h"
#include "rapidjson/memorystream.h"

using namespace std;
using rapidjson::Document;
using rapidjson::StringBuffer;
using rapidjson::Writer;
using namespace rapidjson;

void test()
{
	string strPath = "C:\\a.txt";
	string strJson = "{\"path\":\"" + strPath + "\"}";
	cout << strJson << endl;
}

int main(int argc,char *argv[])
{
	test();
	return 0;
}

你以为这是你预期的结果吗？ 用json解析器检验一下， 就发下上面的json串是错误的， 来看看rapidjson组装方法：

#include <iostream>
#include <stdio.h>
#include<unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include<sstream>

// 请自己下载开源的rapidjson
#include "rapidjson/prettywriter.h"
#include "rapidjson/rapidjson.h"
#include "rapidjson/document.h"
#include "rapidjson/stringbuffer.h"
#include "rapidjson/writer.h"
#include "rapidjson/memorystream.h"

using namespace std;
using rapidjson::Document;
using rapidjson::StringBuffer;
using rapidjson::Writer;
using namespace rapidjson;

void test()
{
	string strPath = "C:\\a.txt";

	Document document;
	Document::AllocatorType& allocator = document.GetAllocator();

	Value root(kObjectType);
	Value name(kStringType);
	name.SetString(strPath.c_str(),allocator);
	root.AddMember("pash",name,allocator);
	
	root.AddMember("id",123,allocator);

	StringBuffer buffer;
	Writer<StringBuffer> writer(buffer);
	root.Accept(writer);
	string reststring = buffer.GetString();
	
	cout << reststring << endl;
}

int main(int argc,char *argv[])
{
	test();
	return 0;
}