C++学习笔记-利用rapidJSON读取JSON数据

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JSON文件如下：

{
   "errorCode":0,
   "reason":"OK",
   "result":
   {"userId":10086,"name":"中国移动"},
   
   "numbers":[110,120,119,911]
}

目录结构如下：

程序运行截图如下：

源码如下：

#include <iostream>
#include <string>
#include "rapidjson/document.h"
#include "rapidjson/writer.h"
#include "rapidjson/stringbuffer.h"

using namespace rapidjson;
using namespace std;


string readfile(const char *filename){
	FILE *fp = fopen(filename, "rb");
	if(!fp){
		printf("open failed! file: %s", filename);
		return "";
	}

	char *buf = new char[1024*16];
	int n = fread(buf, 1, 1024*16, fp);
	fclose(fp);

	string result;
	if(n>=0){
		result.append(buf, 0, n);
	}
	delete []buf;
	return result;
}

int parseJSON(const char *jsonstr){
	Document d;
	if(d.Parse(jsonstr).HasParseError()){
		printf("parse error!\n");
		return -1;
	}
	if(!d.IsObject()){
		printf("should be an object!\n");
		return -1;
	}
	if(d.HasMember("errorCode")){
		Value &m = d["errorCode"];
		int v = m.GetInt();
		printf("errorCode: %d\n", v);
	}
	printf("show numbers: \n");
	if(d.HasMember("numbers")){
		Value &m = d["numbers"];
		if(m.IsArray()){
			for(int i = 0; i < m.Size(); i++){
				Value &e = m[i];
				int n = e.GetInt();
				printf("%d,", n);
			}
		}
	}
	return 0;
}

int parseJSON2(const char *jsonstr){
	Document d;
	if(d.Parse(jsonstr).HasParseError()){
		throw string("parse error!\n");
	}
	if(!d.IsObject()){
		throw string("should be an object!\n");
	}
	if(!d.HasMember("errorCode")){
		throw string("'errorCode' no found!");
	}

	Value &m = d["errorCode"];
	int v = m.GetInt();
	printf("errorCode: %d\n", v);
	printf("show numbers:\n");
	if(d.HasMember("numbers")){
		Value &m = d["numbers"];
		if(m.IsArray()){
			for(int i = 0; i < m.Size(); i++){
				Value &e = m[i];
				int n = e.GetInt();
				printf("%d", n);
			}
		}
	}
	return 0;
}

int main(){

	string jsonstr = readfile("example.json");
	//parseJSON(jsonstr.c_str());

	try{
		parseJSON2(jsonstr.c_str());
	}catch(string e){
		printf("error: %s \n", e.c_str());
	}
	getchar();
	return 0;
}