[转载]C++URL编码转换

#pragma once

#include <iostream>
#include <string>
#include <windows.h>

using namespace std;

class strCoding
{
public:
    strCoding(void);
    ~strCoding(void);
    
    // utf_8 转 gb2312
    void UTF_8ToGB2312(string &pOut, char *pText, int pLen);
    // gb2312 转 utf_8
    void GB2312ToUTF_8(string& pOut, char *pText, int pLen);
    // url_gb2312 编码
    string UrlGB2312(char *str);
    // url_utf8 编码
    string UrlUTF8(char *str);
    // url_utf8 解码
    string UrlUTF8Decode(string str);
    // url_gb2312 解码
    string UrlGB2312Decode(string str);

private:
    void Gb2312ToUnicode(WCHAR *pOut, char *gbBuffer);
    void UTF_8ToUnicode(WCHAR *pOut, char *pText);
    void UnicodeToUTF_8(char *pOut, WCHAR *pText);
    void UnicodeToGB2312(char *pOut, WCHAR uData);
    char CharToInt(char ch);
    char StrToBin(char *str);
};


strCoding::strCoding(void)
{
}

strCoding::~strCoding(void)
{
}

void strCoding::Gb2312ToUnicode(WCHAR *pOut, char *gbBuffer)
{
    ::MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, gbBuffer, 2, pOut, 1);
    return;
}

void strCoding::UTF_8ToUnicode(WCHAR *pOut, 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 strCoding::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 strCoding::UnicodeToGB2312(char *pOut, WCHAR uData)
{
    WideCharToMultiByte(CP_ACP, NULL, &uData, 1, pOut, sizeof(WCHAR), NULL, NULL);
    return;
}

// 做为解Url使用
char strCoding::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 strCoding::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 strCoding::UTF_8ToGB2312(string &pOut, 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 UTF-8
void strCoding::GB2312ToUTF_8(string& pOut, 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 strCoding::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 strCoding::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 strCoding::UrlGB2312Decode(string str)
{
    string output = "";
    char tmp[2];
    int i = 0, idx = 0, ndx, 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 strCoding::UrlUTF8Decode(string str)
{
    string output = "";
    string temp = UrlGB2312Decode(str);
    UTF_8ToGB2312(output, (char *)temp.data(), strlen(temp.data()));
    return output;
}