文章目录
- 前言
- 一、json
- 1.引入库
- 2. 使用步骤
- 2.Calculator.hpp
- 3.Task.hpp
- 4.serverCal.hpp
- 新客户端
前言
本章内容主要对上一章的网络计算器客户端和服务器进行一些Bug修正与功能改进。 并学习如何使用json库和daemon函数。
一、json
在我们自己的电脑上一些软件的文件夹中，我们经常能看到.json后缀的文件，那么这种文件是用来干什么的呢？
这就要说到我们上节课所讲的序列化和反序列化了，相信如果大家自己如果尝试写了一遍之后，会发现序列化和反序列化还是比较难写的。
而市面上，是存在这么一个库被广泛引用来做序列化和反序列化，他就是json库。
json库是一个第三方库，所以我们的Linux服务器一般是不自带的，需要下载安装。
sudo yum install -y jsoncpp-devel
安装后，它的头文件位于
ls /usr/include/jsoncpp/json
因为是第三方库，所以它也需要链接动态库。
ls /lib64/libjsoncpp.so
1.引入库
代码如下（示例）：
#include <jsoncpp/json/json.h>
g++编译
Lib=-ljsoncpp
serverCal:main.ccg++ -o $@ $^ -std=c++11 -lpthread $(Lib)clientCal:clientCal.ccg++ -o $@ $^ -std=c++11 $(Lib)
2. 使用步骤
#pragma once
#include <iostream>
#include <string>
#include "log.hpp"
#include <jsoncpp/json/json.h>extern Log lg;
const char blank_space_sep = ' ';
const char protocol_sep = '\n';enum Code
{Div_Zero_Err = 1,Mod_Zeor_Err,Operatorr_Err,Float_Mod_Err
};enum Type
{Type_Int = 1,Type_Double = 2
};// 多态版本bool CheckType(std::string &in_str, int* type)
{Json::Value root;Json::Reader reader;bool suc = reader.parse(in_str, root);if (!suc){lg(Warning, "Deserialize Failed...");return false;}*type = root["type"].asInt();return true;
}class Request
{
public:Request() {}Request(char op): _op(op) {}virtual bool serialize() {}virtual bool deserialize() {}public:char _op;
};class IntRequest : public Request
{
public:IntRequest() {}IntRequest(int x, int y, char op): _x(x), _y(y), Request(op) {}virtual bool serialize(std::string *out_str){Json::Value root;root["x"] = _x;root["y"] = _y;root["op"] = _op;root["type"] = 1;Json::FastWriter writer;*out_str = writer.write(root);return true;}virtual bool deserialize(std::string &in_str){Json::Value root;Json::Reader reader;bool suc = reader.parse(in_str, root);if (!suc){lg(Warning, "Request Deserialize Failed...");return false;}_x = root["x"].asInt();_y = root["y"].asInt();_op = root["op"].asInt();Json::FastWriter writer;in_str.erase(0, writer.write(root).size());std::cout << "已经删除已解析报头..." << std::endl;return true;}public:int _x;int _y;
};class DoubleRequest : public Request
{
public:DoubleRequest() {}DoubleRequest(double x, double y, char op): _x(x), _y(y), Request(op) {}virtual bool serialize(std::string *out_str){Json::Value root;root["x"] = _x;root["y"] = _y;root["op"] = _op;root["type"] = 2;Json::FastWriter writer;*out_str = writer.write(root);return true;}virtual bool deserialize(std::string &in_str){Json::Value root;Json::Reader reader;bool suc = reader.parse(in_str, root);if (!suc){lg(Warning, "Request Deserialize Failed...");return false;}_x = root["x"].asDouble();_y = root["y"].asDouble();_op = root["op"].asInt();Json::FastWriter writer;in_str.erase(0, writer.write(root).size());return true;}public:double _x;double _y;
};class Respond
{
public:Respond() {}Respond(int code): _code(code) {}virtual bool serialize() {}virtual bool deserialize() {}public:int _code = -1;
};class IntRespond : public Respond
{
public:IntRespond() {}IntRespond(int result, int code): _result(result), Respond(code) {}virtual bool serialize(std::string *out_str){Json::Value root;root["result"] = _result;root["code"] = _code;root["type"] = 1;Json::FastWriter writer;*out_str = writer.write(root);return true;}virtual bool deserialize(const std::string &in_str){Json::Value root;Json::Reader reader;bool suc = reader.parse(in_str, root);if (!suc){lg(Warning, "Respond Deserialize Failed...");return false;}_result = root["result"].asInt();_code = root["code"].asInt();return true;}public:int _result;
};class DoubleRespond : public Respond
{
public:DoubleRespond() {}DoubleRespond(double result, int code): _result(result), Respond(code) {}virtual bool serialize(std::string *out_str){Json::Value root;root["result"] = _result;root["code"] = _code;root["type"] = 2;Json::FastWriter writer;*out_str = writer.write(root);return true;}virtual bool deserialize(const std::string &in_str){Json::Value root;Json::Reader reader;bool suc = reader.parse(in_str, root);if (!suc){lg(Warning, "Respond Deserialize Failed...");return false;}_result = root["result"].asDouble();_code = root["code"].asInt();return true;}public:double _result;
};2.Calculator.hpp
#pragma once
#include "protocol.hpp"class Calculator
{
public:Calculator() {}IntRespond calculate(const IntRequest &rq){IntRespond rs;switch (rq._op){case '+':rs._result = rq._x + rq._y;break;case '-':rs._result = rq._x - rq._y;break;case '*':rs._result = rq._x * rq._y;break;case '/':if (rq._y == 0){lg(Warning, "Found Div Zero Error...");rs._code = Div_Zero_Err;return rs;}rs._result = rq._x / rq._y;break;case '%':if (rq._y == 0){lg(Warning, "Found Mod Zero Error...");rs._code = Mod_Zeor_Err;return rs;}rs._result = rq._x % rq._y;break;default:lg(Warning, "Found Operator Error...");rs._code = Operatorr_Err;return rs;}rs._code = 0;return rs;}DoubleRespond calculate(const DoubleRequest &rq){DoubleRespond rs;switch (rq._op){case '+':rs._result = rq._x + rq._y;break;case '-':rs._result = rq._x - rq._y;break;case '*':rs._result = rq._x * rq._y;break;case '/':if (rq._y == 0){lg(Warning, "Found Div Zero Error...");rs._code = Div_Zero_Err;return rs;}rs._result = rq._x / rq._y;break;case '%':lg(Warning, "Float Mod Error...");rs._code = Float_Mod_Err;return rs;default:lg(Warning, "Found Operator Error...");rs._code = Operatorr_Err;return rs;}rs._code = 0;return rs;}
};3.Task.hpp
#pragma once
#include "Socket.hpp"
#include "protocol.hpp"
#include "Calculator.hpp"
class Task
{
public:Task(int socket_fd): _socket_fd(socket_fd){}void IntHandle(std::string &message){IntRequest rq;Calculator cal;// 因为可能message里面已经存在了多个报文，所以就需要一次性多次处理if (!rq.deserialize(message)){// 反序列化失败说明里面的数据可能出现数据丢失等情况，出现这种情况说明我们的报文数据不再可信，最直接的办法就是丢弃全部报文！message = "";return;}IntRespond rs = cal.calculate(rq);std::string res;rs.serialize(&res);printf("%d %c %d = %d\n", rq._x, rq._op, rq._y, rs._result);write(_socket_fd, res.c_str(), res.size());}void DoubleHandle(std::string &message){DoubleRequest rq;Calculator cal;// 因为可能message里面已经存在了多个报文，所以就需要一次性多次处理if (!rq.deserialize(message)){// 反序列化失败说明里面的数据可能出现数据丢失等情况，出现这种情况说明我们的报文数据不再可信，最直接的办法就是丢弃全部报文！message = "";return;}DoubleRespond rs = cal.calculate(rq);std::string res;rs.serialize(&res);printf("%lf %c %lf = %lf\n", rq._x, rq._op, rq._y, rs._result);write(_socket_fd, res.c_str(), res.size());}void run(){char in_buffer[1024];std::string message = "";while (true){memset(in_buffer, 0, sizeof in_buffer);int n = read(_socket_fd, (void *)in_buffer, sizeof in_buffer - 1);if (n == 0){lg(Warning, "Connection closed by foreign host, socketfd[%d] closed...", _socket_fd);break;}else if (n < 0){lg(Warning, "Read Error, socketfd[%d]...", _socket_fd);break;}in_buffer[n] = 0;message = in_buffer;std::cout << "报文大小: " << message.size() << " ,报文内容: " << message << std::endl;// 判断发来的数据类型while (!message.empty()){int type;if (!CheckType(message, &type)){//报文内容出现问题message = "";break;}if (type == 1){IntHandle(message);}else if (type == 2){DoubleHandle(message);}else{lg(Warning, "Type Error, type: %d ...", type);}}}}void operator()(){run();close(_socket_fd);}~Task(){}private:int _socket_fd;
};
4.serverCal.hpp
#pragma once#include "Socket.hpp"
#include "protocol.hpp"
#include "threadPool.hpp"
#include "Task.hpp"
class ServerCal
{
public:ServerCal(){}void Init(const int sinfamily, const std::string &ip, const uint16_t port){_listensock.Init();_listensock.Bind(sinfamily, ip, port);_listensock.Listen();}void Run(){daemon(0, 0); //仅此这里添加了一个守护线程功能ThreadPool<Task> *tp = ThreadPool<Task>::GetInstance();tp->Start();struct sockaddr_in client;while (true){memset(&client, 0, sizeof client);socklen_t len;int socketfd = _listensock.Accept(&client, &len);if (socketfd < 0)continue;tp->Push(socketfd);}}private:Socket _listensock;
};
这里我添加了守护线程的功能，使用的是系统库自带的函数。
nochdir如果被设为0，则更改工作路径为“/”根目录，否则则什么也不敢。
noclose如果被设为0，则将标准输入输出错误重定向到/dev/null文件中，/dev/null文件我们上章是讲过的。
其他的文件我没有变动，需要的可以在我上一个文章复制粘贴或者到我的gitee自行拷贝。
新客户端
#include "Socket.hpp"
#include "protocol.hpp"#define VALID_OP 5
const char valid_operator[VALID_OP] = {'+', '-', '*', '/', '%'};static int localfd = -1;void Usage(const char *mes)
{std::cout << "Usage: " << mes << " ip[xxx.xxx.xxx.xxx] port[8080-9000]" << std::endl;
}bool __CheckNumber(const std::string &str)
{for (const char c : str){if ((!isdigit(c)) && (c != '.')){return false;}}return true;
}bool __CheckOp(const std::string &op)
{if (op.size() != 1){return false;}for (int i = 0; i < VALID_OP; i++){if (op.find(valid_operator[i]) != std::string::npos)break;if (i == 4){return false;}}return true;
}bool CheckSafe(const std::string &x, const std::string &op, const std::string &y, int *type)
{if (!__CheckOp(op)){std::cout << "Helper: 使用了除 + - * / % 以外的运算符" << std::endl;return false;}if (!__CheckNumber(x) || !__CheckNumber(y)){std::cout << "Helper: 请输入正确的数字" << std::endl;return false;}if ((x.find('.') != std::string::npos) || (y.find('.') != std::string::npos)){// 说明这是浮点数运算*type = 2;return true;}*type = 1;return true;
}void IntHandle(const std::string &x, const std::string &op, const std::string &y, std::string &message)
{IntRequest rq;IntRespond rs;rq._x = std::stoi(x);rq._y = std::stoi(y);rq._op = op[0];rq.serialize(&message);write(localfd, message.c_str(), message.size());// 开始等待结果char buffer[1024];int n = read(localfd, buffer, sizeof buffer - 1);if (n == 0){lg(Warning, "Connection closed by foreign host, socketfd[%d] closed...", localfd);exit(1);}else if (n < 0){lg(Warning, "Read Error, socketfd[%d]...", localfd);exit(2);}buffer[n] = 0;std::string res = buffer;std::cout << res << std::endl;rs.deserialize(res);if (rs._code != 0){switch (rs._code){case 1:std::cout << "出现除0错误" << std::endl;break;case 2:std::cout << "出现模0错误" << std::endl;break;case 3:std::cout << "使用了除 + - * / % 以外的运算符" << std::endl;break;default:std::cout << "发生未知错误" << std::endl;break;}return;}printf("%d %c %d = %d\n", rq._x, rq._op, rq._y, rs._result);
}void DoubleHandle(const std::string &x, const std::string &op, const std::string &y, std::string &message)
{DoubleRequest rq;DoubleRespond rs;rq._x = std::stod(x);rq._y = std::stod(y);rq._op = op[0];rq.serialize(&message);write(localfd, message.c_str(), message.size());// 开始等待结果char buffer[1024];int n = read(localfd, buffer, sizeof buffer - 1);if (n == 0){lg(Warning, "Connection closed by foreign host, socketfd[%d] closed...", localfd);exit(1);}else if (n < 0){lg(Warning, "Read Error, socketfd[%d]...", localfd);exit(2);}buffer[n] = 0;std::string res = buffer;std::cout << res << std::endl;rs.deserialize(res);if (rs._code != 0){switch (rs._code){case 1:std::cout << "出现除0错误" << std::endl;break;case 2:std::cout << "出现模0错误" << std::endl;break;case 3:std::cout << "使用了除 + - * / % 以外的运算符" << std::endl;break;default:std::cout << "发生未知错误" << std::endl;break;}return;}printf("%lf %c %lf = %lf\n", rq._x, rq._op, rq._y, rs._result);
}int main(int argc, char *argv[])
{if (argc != 3){Usage("./clientCal");}Socket local;local.Init();int n = local.Connect(argv[1], argv[2]);if (n < 0){return 1;}localfd = local.Getfd();std::cout << " 简易计算器, 目前仅支持\" + - * / %\"运算符 " << std::endl;std::cout << " 数字和运算符请用空格或回车隔开" << std::endl;std::string x, op, y;int type;std::string message;while (true){std::cout << "请输入您的算式@ ";std::cin >> x >> op >> y;if (!CheckSafe(x, op, y, &type)){continue;}std::cout << type << std::endl;if (type == 1){IntHandle(x,op,y,message);}else if(type ==2){DoubleHandle(x,op,y,message);}else{lg(Warning, "Type Error, type: %d ...", type);exit(3);}}return 0;
}
添加了许多输入的安全检查，不检查引发的问题太多了！
