C++实现json形式的Socket传输图片

本文实例为大家分享了C++实现json形式的Socket传输图片的具体代码，供大家参考，具体内容如下

大致流程：客户端读取图片，经过Base64编码，转成字符串的形式，保存到json中，通过socket传到服务端，然后Base64解码，再转换成图片

一.服务端

1.main.cpp

#include <iostream>
#include <stdio.h>
#include "Base64_1.h"
#include <winsock2.h>
#include "json1.hpp"

#pragma comment(lib,"ws2_32.lib")
using json = nlohmann::json;

char revData[3888888];

bool WritePhotoFile(std::basic_string<TCHAR> strFileName, std::string &strData)
{
 HANDLE hFile;
 hFile = CreateFile(strFileName.c_str(), GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);

 if (hFile == INVALID_HANDLE_VALUE)
 {
 return false;
 }

 CBase64 base64;

 int datalen(0);
 DWORD dwritelen(0);
 std::string strdcode = base64.Decode(strData.data(), strData.size(), datalen);
 if (!WriteFile(hFile, strdcode.data(), datalen, &dwritelen, NULL))
 {
 CloseHandle(hFile);
 return false;
 }
 CloseHandle(hFile);
 return true;
}

int main(int argc, char* argv[])
{
 //初始化WSA
 WORD sockVersion = MAKEWORD(2, 2);
 WSADATA wsaData;
 if (WSAStartup(sockVersion, &wsaData) != 0)
 {
 return 0;
 }

 //创建套接字
 SOCKET slisten = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
 if (slisten == INVALID_SOCKET)
 {
 printf("socket error !");
 return 0;
 }

 //绑定IP和端口
 sockaddr_in sin;
 sin.sin_family = AF_INET;
 sin.sin_port = htons(8888);
 sin.sin_addr.S_un.S_addr = INADDR_ANY;

 if (bind(slisten, (LPSOCKADDR)&sin, sizeof(sin)) == SOCKET_ERROR)
 {
 printf("bind error !");
 }

 //开始监听
 if (listen(slisten, 5) == SOCKET_ERROR)
 {
 printf("listen error !");
 return 0;
 }

 //循环接收数据
 SOCKET sClient;
 sockaddr_in remoteAddr;
 int nAddrlen = sizeof(remoteAddr);

 //revData = (char*)malloc(sizeof(char) * 1000000);
 int i = 1;
 while (true)
 {
 printf("等待连接...\n");
 sClient = accept(slisten, (SOCKADDR *)&remoteAddr, &nAddrlen);
 if (sClient == INVALID_SOCKET)
 {
 printf("accept error !");
 continue;
 }
 printf("接受到一个连接：%s \r\n", inet_ntoa(remoteAddr.sin_addr));

 //接收数据
 int ret = recv(sClient, revData, 3888888, 0);
 if (ret > 0)
 {
 revData[ret] = 0x00;
 json o = json::parse(revData);
 for (json::iterator it = o.begin(); it != o.end(); ++it) {
 //std::cout << it.key() << " : " << it.value() << "\n";
 if (it.key() == "imgA"|| it.key() == "imgB")
 {
 std::string num = std::to_string(i++);
 std::string strFileName = "D:\\"+ num +".jpg";
 std::string val = it.value();
 WritePhotoFile(strFileName, val);
 }

 }
 //std::cout<< json::parse(revData)<< std::endl;
 //printf(revData);
 }

 //发送数据
 //const char * sendData = "你好，TCP客户端！\n";
 //send(sClient, sendData, strlen(sendData), 0);
 closesocket(sClient);
 }

 closesocket(slisten);
 WSACleanup();

 return 0;
}

2.Base64.cpp

#include"Base64_1.h"

CBase64::CBase64()
{

}

CBase64::~CBase64()
{

}

std::string CBase64::Encode(const char* Data, int DataByte)
{
 //编码表
 const char EncodeTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 //返回值
 std::string strEncode;
 unsigned char Tmp[4] = { 0 };
 int LineLength = 0;
 for (int i = 0; i<(int)(DataByte / 3); i++)
 {
 Tmp[1] = *Data++;
 Tmp[2] = *Data++;
 Tmp[3] = *Data++;
 strEncode += EncodeTable[Tmp[1] >> 2];
 strEncode += EncodeTable[((Tmp[1] << 4) | (Tmp[2] >> 4)) & 0x3F];
 strEncode += EncodeTable[((Tmp[2] << 2) | (Tmp[3] >> 6)) & 0x3F];
 strEncode += EncodeTable[Tmp[3] & 0x3F];
 if (LineLength += 4, LineLength == 76) { strEncode += "\r\n"; LineLength = 0; }
 }
 //对剩余数据进行编码
 int Mod = DataByte % 3;
 if (Mod == 1)
 {
 Tmp[1] = *Data++;
 strEncode += EncodeTable[(Tmp[1] & 0xFC) >> 2];
 strEncode += EncodeTable[((Tmp[1] & 0x03) << 4)];
 strEncode += "==";
 }
 else if (Mod == 2)
 {
 Tmp[1] = *Data++;
 Tmp[2] = *Data++;
 strEncode += EncodeTable[(Tmp[1] & 0xFC) >> 2];
 strEncode += EncodeTable[((Tmp[1] & 0x03) << 4) | ((Tmp[2] & 0xF0) >> 4)];
 strEncode += EncodeTable[((Tmp[2] & 0x0F) << 2)];
 strEncode += "=";
 }

 return strEncode;
}

std::string CBase64::Decode(const char* Data, int DataByte, int& OutByte)
{
 //解码表
 const char DecodeTable[] =
 {
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 62, // '+'
 0, 0, 0,
 63, // '/'
 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // '0'-'9'
 0, 0, 0, 0, 0, 0, 0,
 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // 'A'-'Z'
 0, 0, 0, 0, 0, 0,
 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // 'a'-'z'
 };
 //返回值
 std::string strDecode;
 int nValue;
 int i = 0;
 while (i < DataByte)
 {
 if (*Data != '\r' && *Data != '\n')
 {
 nValue = DecodeTable[*Data++] << 18;
 nValue += DecodeTable[*Data++] << 12;
 strDecode += (nValue & 0x00FF0000) >> 16;
 OutByte++;
 if (*Data != '=')
 {
 nValue += DecodeTable[*Data++] << 6;
 strDecode += (nValue & 0x0000FF00) >> 8;
 OutByte++;
 if (*Data != '=')
 {
 nValue += DecodeTable[*Data++];
 strDecode += nValue & 0x000000FF;
 OutByte++;
 }
 }
 i += 4;
 }
 else// 回车换行,跳过
 {
 Data++;
 i++;
 }
 }
 return strDecode;
}

3.Base64_1.h

//++Base64.h

#pragma once
#include <string>

class CBase64
{
public:
public:
 CBase64();
 ~CBase64();

 /*编码
 DataByte
 [in]输入的数据长度,以字节为单位
 */
 std::string Encode(const char* Data, int DataByte);

 /*解码
 DataByte
 [in]输入的数据长度,以字节为单位
 OutByte
 [out]输出的数据长度,以字节为单位,请不要通过返回值计算
 输出数据的长度
 */
 std::string Decode(const char* Data, int DataByte, int& OutByte);

};

4.json.hpp 去网上下载吧，个人感觉比jsoncpp好用一些（我里面的json1.hpp就是json.hpp）

二.客户端

1.main.cpp

#include<WINSOCK2.H>
#include<STDIO.H>
#include<iostream>
#include<cstring>
#include <string>
#include <fstream>
#include "Bash64.h"
#include "json1.hpp"

using namespace std;
using json = nlohmann::json;
#pragma comment(lib, "ws2_32.lib")

char chBuf1[3888888], chBuf2[3888888];

int main()
{

 FILE *fIn1, *fIn2;
 int nRead1, nRead2;

 WORD sockVersion = MAKEWORD(2, 2);
 WSADATA data;
 if (WSAStartup(sockVersion, &data) != 0)
 {
 return 0;
 }

 std::string num = std::to_string(1);
 std::string chFileIn1 = "E:\\"+num+".jpg";
 num = std::to_string(2);
 std::string chFileIn2 = "E:\\" + num + ".jpg";

 SOCKET sclient = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
 if (sclient == INVALID_SOCKET)
 {
 printf("invalid socket!");
 return 0;
 }

 sockaddr_in serAddr;
 serAddr.sin_family = AF_INET;
 serAddr.sin_port = htons(8888);
 serAddr.sin_addr.S_un.S_addr = inet_addr("192.168.3.72");
 if (connect(sclient, (sockaddr *)&serAddr, sizeof(serAddr)) == SOCKET_ERROR)
 { //连接失败
 printf("connect error !");
 closesocket(sclient);
 return 0;
 }

 char chFileIn3[100], chFileIn4[100];
 strcpy(chFileIn3, chFileIn1.c_str());
 strcpy(chFileIn4, chFileIn2.c_str());
 fIn1 = fopen(chFileIn3, "rb");
 fIn2 = fopen(chFileIn4, "rb");
 if (fIn1 == NULL || fIn2 == NULL)
 {
 printf("打开读取文件失败");
 return 0;
 }
 //读文件
 json data1;

 //fread()读取成功返回值为实际读回的数据个数(单位为Byte)
 nRead1 = fread(chBuf1, sizeof(char), 3888888, fIn1);
 nRead2 = fread(chBuf2, sizeof(char), 3888888, fIn2);
 //base64编码 封装进json
 string imgBase64_1 = base64_encode(chBuf1, nRead1);
 string imgBase64_2 = base64_encode(chBuf2, nRead2);
 data1["imgA"] = imgBase64_1;
 data1["imgB"] = imgBase64_2;
 fclose(fIn1);
 fclose(fIn2);

 //显式转换为string
 std::string s = data1.dump();
 const char * sendData;
 sendData = s.c_str(); //string转const char*
 //char * sendData = "你好，TCP服务端，我是客户端\n";
 send(sclient, sendData, strlen(sendData), 0);

 //send()用来将数据由指定的socket传给对方主机
 //int send(int s, const void * msg, int len, unsigned int flags)
 //s为已建立好连接的socket，msg指向数据内容，len则为数据长度，参数flags一般设0
 //成功则返回实际传送出去的字符数，失败返回-1，错误原因存于error 

 char recData[266680];
 int ret = recv(sclient, recData, 266680, 0);
 if (ret>0) {
 recData[ret] = 0x00;
 //printf(recData);
 }
 closesocket(sclient);

 WSACleanup();
 system("pause");
 return 0;

}

2.Bash64.h

#ifndef __BASE64_H__
#define __BASE64_H__

#include <iostream>
#include <string>

static const std::string base64_chars =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/";

static inline bool is_base64(const char c)
{
 return (isalnum(c) || (c == '+') || (c == '/'));
}

std::string base64_encode(const char * bytes_to_encode, unsigned int in_len)
{
 std::string ret;
 int i = 0;
 int j = 0;
 unsigned char char_array_3[3];
 unsigned char char_array_4[4];

 while (in_len--)
 {
 char_array_3[i++] = *(bytes_to_encode++);
 if (i == 3)
 {
 char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
 char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
 char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
 char_array_4[3] = char_array_3[2] & 0x3f;
 for (i = 0; (i <4); i++)
 {
 ret += base64_chars[char_array_4[i]];
 }
 i = 0;
 }
 }
 if (i)
 {
 for (j = i; j < 3; j++)
 {
 char_array_3[j] = '\0';
 }

 char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
 char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
 char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
 char_array_4[3] = char_array_3[2] & 0x3f;

 for (j = 0; (j < i + 1); j++)
 {
 ret += base64_chars[char_array_4[j]];
 }

 while ((i++ < 3))
 {
 ret += '=';
 }

 }
 return ret;
}

std::string base64_decode(std::string const & encoded_string)
{
 int in_len = (int)encoded_string.size();
 int i = 0;
 int j = 0;
 int in_ = 0;
 unsigned char char_array_4[4], char_array_3[3];
 std::string ret;

 while (in_len-- && (encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
 char_array_4[i++] = encoded_string[in_]; in_++;
 if (i == 4) {
 for (i = 0; i <4; i++)
 char_array_4[i] = base64_chars.find(char_array_4[i]);

 char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
 char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
 char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

 for (i = 0; (i < 3); i++)
 ret += char_array_3[i];
 i = 0;
 }
 }
 if (i) {
 for (j = i; j <4; j++)
 char_array_4[j] = 0;

 for (j = 0; j <4; j++)
 char_array_4[j] = base64_chars.find(char_array_4[j]);

 char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
 char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
 char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

 for (j = 0; (j < i - 1); j++) ret += char_array_3[j];
 }

 return ret;
}
#endif

3.json.hpp  上面有链接（我里面的json1.hpp就是json.hpp）

Hit:服务端和客户端的Base64文件不一样，是因为当时服务端接收json时，Base64解码成图片出现了问题，又去找大神的博客，把服务端的Base64文件换了。然后能进行正常的传输图片，客户端就懒得换了~

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。