[C++]中文Windows系统处理base64的正确方式
由于Visual Studio在中文系统下是用GB2312处理字符串，如果base64结果要跟其他语言，特别是网页开发的一般默认utf-8编码，就会出现乱码。
解决方法就是先转换文本的编码。最终结果使用这个在线工具验证通过
先看main函数
int main()
{
//这是WINDOWS API函数
LANGID lang = GetUserDefaultLangID();
cout << lang << endl;
string strOriginal = "随意吧输入一定文字*（）————abcdefg";
string strTemp;
TextConvert convertor;
// 对简体中文编码，从GB2312转为UTF8
// 东亚有些语言编码也会引起问题，需要用特殊的方法转换
if (lang == 0x804) {
convertor.GB2312ToUTF_8(strTemp, strOriginal.c_str(), strOriginal.length());
}
else {
strTemp = strOriginal;
}
Base64Convert base64;
string encode = base64.Encode((unsigned char*)strTemp.c_str(), strTemp.length());
cout << encode << endl;
strTemp = base64.Decode(encode.c_str(), encode.length());
string decode;
convertor.UTF_8ToGB2312(decode, strTemp.c_str(), strTemp.length());
cout << decode << endl;
}
TextConvert.h文件
#pragma once
#include <iostream>
#include <string>
#include <windows.h>
using namespace std;
class TextConvert
{
public:
TextConvert();
~TextConvert();
void UTF_8ToGB2312(string &pOut, const char *pText, int pLen);//utf_8转为gb2312
void GB2312ToUTF_8(string &pOut, const char *pText, int pLen); //gb2312 转utf_8
string UrlGB2312(char * str); //urlgb2312编码
string UrlUTF8(char * str); //urlutf8 编码
string UrlUTF8Decode(string str); //urlutf8解码
string UrlGB2312Decode(string str); //urlgb2312解码
private:
void Gb2312ToUnicode(WCHAR* pOut, const char *gbBuffer);
void UTF_8ToUnicode(WCHAR* pOut, const char *pText);
void UnicodeToUTF_8(char* pOut, WCHAR* pText);
void UnicodeToGB2312(char* pOut, WCHAR uData);
char CharToInt(char ch);
char StrToBin(char *str);
};
TextConvert.cpp文件
#include "stdafx.h"
#include "TextConvert.h"
TextConvert::TextConvert()
{
}
TextConvert::~TextConvert()
{
}
void TextConvert::Gb2312ToUnicode(WCHAR* pOut, const char *gbBuffer)
{
::MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, gbBuffer, 2, pOut, 1);
return;
}
void TextConvert::UTF_8ToUnicode(WCHAR* pOut, const char *pText)
{
char* uchar = (char *)pOut;
uchar[1] = ((pText[0] & 0x0F) << 4) + ((pText[1] >> 2) & 0x0F);
uchar[0] = ((pText[1] & 0x03) << 6) + (pText[2] & 0x3F);
return;
}
void TextConvert::UnicodeToUTF_8(char* pOut, WCHAR* pText)
{
// 注意 WCHAR高低字的顺序,低字节在前，高字节在后
char* pchar = (char *)pText;
pOut[0] = (0xE0 | ((pchar[1] & 0xF0) >> 4));
pOut[1] = (0x80 | ((pchar[1] & 0x0F) << 2)) + ((pchar[0] & 0xC0) >> 6);
pOut[2] = (0x80 | (pchar[0] & 0x3F));
return;
}
void TextConvert::UnicodeToGB2312(char* pOut, WCHAR uData)
{
WideCharToMultiByte(CP_ACP, NULL, &uData, 1, pOut, sizeof(WCHAR), NULL, NULL);
return;
}
//做为解Url使用
char TextConvert::CharToInt(char ch) {
if (ch >= '0' && ch <= '9')return (char)(ch - '0');
if (ch >= 'a' && ch <= 'f')return (char)(ch - 'a' + 10);
if (ch >= 'A' && ch <= 'F')return (char)(ch - 'A' + 10);
return -1;
}
char TextConvert::StrToBin(char *str) {
char tempWord[2];
char chn;
tempWord[0] = CharToInt(str[0]); //make the B to 11 -- 00001011
tempWord[1] = CharToInt(str[1]); //make the 0 to 0 -- 00000000
chn = (tempWord[0] << 4) | tempWord[1]; //to change the BO to 10110000
return chn;
}
//UTF_8 转gb2312
void TextConvert::UTF_8ToGB2312(string &pOut, const char *pText, int pLen)
{
char buf[4];
char* rst = new char[pLen + (pLen >> 2) + 2];
memset(buf, 0, 4);
memset(rst, 0, pLen + (pLen >> 2) + 2);
int i = 0;
int j = 0;
while (i < pLen)
{
if (*(pText + i) >= 0)
{
rst[j++] = pText[i++];
}
else
{
WCHAR Wtemp;
UTF_8ToUnicode(&Wtemp, pText + i);
UnicodeToGB2312(buf, Wtemp);
unsigned short int tmp = 0;
tmp = rst[j] = buf[0];
tmp = rst[j + 1] = buf[1];
tmp = rst[j + 2] = buf[2];
//newBuf[j] = Ctemp[0];
//newBuf[j + 1] = Ctemp[1];
i += 3;
j += 2;
}
}
rst[j] = '\0';
pOut = rst;
delete[]rst;
}
//GB2312 转为 UTF-8
void TextConvert::GB2312ToUTF_8(string& pOut, const char *pText, int pLen)
{
char buf[4];
memset(buf, 0, 4);
pOut.clear();
int i = 0;
while (i < pLen)
{
//如果是英文直接复制就可以
if (pText[i] >= 0)
{
char asciistr[2] = { 0 };
asciistr[0] = (pText[i++]);
pOut.append(asciistr);
}
else
{
WCHAR pbuffer;
Gb2312ToUnicode(&pbuffer, pText + i);
UnicodeToUTF_8(buf, &pbuffer);
pOut.append(buf);
i += 2;
}
}
return;
}
//把str编码为网页中的 GB2312 url encode ,英文不变，汉字双字节 如%3D%AE%88
string TextConvert::UrlGB2312(char * str)
{
string dd;
size_t len = strlen(str);
for (size_t i = 0; i<len; i++)
{
if (isalnum((BYTE)str[i]))
{
char tempbuff[2];
sprintf(tempbuff, "%c", str[i]);
dd.append(tempbuff);
}
else if (isspace((BYTE)str[i]))
{
dd.append("+");
}
else
{
char tempbuff[4];
sprintf(tempbuff, "%%%X%X", ((BYTE*)str)[i] >> 4, ((BYTE*)str)[i] % 16);
dd.append(tempbuff);
}
}
return dd;
}
//把str编码为网页中的 UTF-8 url encode ,英文不变，汉字三字节 如%3D%AE%88
string TextConvert::UrlUTF8(char * str)
{
string tt;
string dd;
GB2312ToUTF_8(tt, str, (int)strlen(str));
size_t len = tt.length();
for (size_t i = 0; i<len; i++)
{
if (isalnum((BYTE)tt.at(i)))
{
char tempbuff[2] = { 0 };
sprintf(tempbuff, "%c", (BYTE)tt.at(i));
dd.append(tempbuff);
}
else if (isspace((BYTE)tt.at(i)))
{
dd.append("+");
}
else
{
char tempbuff[4];
sprintf(tempbuff, "%%%X%X", ((BYTE)tt.at(i)) >> 4, ((BYTE)tt.at(i)) % 16);
dd.append(tempbuff);
}
}
return dd;
}
//把url GB2312解码
string TextConvert::UrlGB2312Decode(string str)
{
string output = "";
char tmp[2];
int i = 0, idx = 0, len = str.length();
while (i<len) {
if (str[i] == '%') {
tmp[0] = str[i + 1];
tmp[1] = str[i + 2];
output += StrToBin(tmp);
i = i + 3;
}
else if (str[i] == '+') {
output += ' ';
i++;
}
else {
output += str[i];
i++;
}
}
return output;
}
//把url utf8解码
string TextConvert::UrlUTF8Decode(string str)
{
string output = "";
string temp = UrlGB2312Decode(str);//
UTF_8ToGB2312(output, (char *)temp.data(), strlen(temp.data()));
return output;
}
Base64Convert.h文件
#pragma once
#include <string>
using namespace std;
/**
* Base64 编码/解码
* @author liruixing
*/
class Base64Convert {
private:
std::string _base64_table;
static const char base64_pad = '=';
public:
Base64Convert()
{
_base64_table = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; /*这是Base64编码使用的标准字典*/
}
/**
* 这里必须是unsigned类型，否则编码中文的时候出错
*/
std::string Encode(const unsigned char * str, int bytes);
std::string Decode(const char *str, int bytes);
//void Debug(bool open = true);
};
Base64Convert.cpp文件
#include "stdafx.h"
#include <iostream>
#include "Base64Convert.h"
std::string Base64Convert::Encode(const unsigned char * str, int bytes) {
int num = 0, bin = 0;
std::string _encode_result;
const unsigned char * current;
current = str;
while (bytes > 2) {
_encode_result += _base64_table[current[0] >> 2];
_encode_result += _base64_table[((current[0] & 0x03) << 4) + (current[1] >> 4)];
_encode_result += _base64_table[((current[1] & 0x0f) << 2) + (current[2] >> 6)];
_encode_result += _base64_table[current[2] & 0x3f];
current += 3;
bytes -= 3;
}
if (bytes > 0)
{
_encode_result += _base64_table[current[0] >> 2];
if (bytes % 3 == 1) {
_encode_result += _base64_table[(current[0] & 0x03) << 4];
_encode_result += "==";
}
else if (bytes % 3 == 2) {
_encode_result += _base64_table[((current[0] & 0x03) << 4) + (current[1] >> 4)];
_encode_result += _base64_table[(current[1] & 0x0f) << 2];
_encode_result += "=";
}
}
return _encode_result;
}
std::string Base64Convert::Decode(const char *str, int length) {
//解码表
const char DecodeTable[] =
{
-2, -2, -2, -2, -2, -2, -2, -2, -2, -1, -1, -2, -2, -1, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-1, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, 62, -2, -2, -2, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -2, -2, -2, -2, -2, -2,
-2, 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, -2, -2, -2, -2, -2,
-2, 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, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2
};
int bin = 0, i = 0, pos = 0;
std::string _decode_result;
const char *current = str;
char ch;
while ((ch = *current++) != '\0' && length-- > 0)
{
if (ch == base64_pad) { // 当前一个字符是“=”号
/*
先说明一个概念：在解码时，4个字符为一组进行一轮字符匹配。
两个条件：
1、如果某一轮匹配的第二个是“=”且第三个字符不是“=”，说明这个带解析字符串不合法，直接返回空
2、如果当前“=”不是第二个字符，且后面的字符只包含空白符，则说明这个这个条件合法，可以继续。
*/
if (*current != '=' && (i % 4) == 1) {
return NULL;
}
continue;
}
ch = DecodeTable[ch];
//这个很重要，用来过滤所有不合法的字符
if (ch < 0) { /* a space or some other separator character, we simply skip over */
continue;
}
switch (i % 4)
{
case 0:
bin = ch << 2;
break;
case 1:
bin |= ch >> 4;
_decode_result += bin;
bin = (ch & 0x0f) << 4;
break;
case 2:
bin |= ch >> 2;
_decode_result += bin;
bin = (ch & 0x03) << 6;
break;
case 3:
bin |= ch;
_decode_result += bin;
break;
}
i++;
}
return _decode_result;
}
注: 以上两个类来自不同的博文
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