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;
}
结果: {"path":"C:\a.txt"}
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;
}
结果:{"pash":"C:\\a.txt","id":123}
这才是预期中的json串吗, 搞定。 自己组装json串是流氓行为, 尽管, 我偶尔也这么组装简单的字符串。