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

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