C++语言的url encode 和decode

落日映苍穹つ 2022-09-20 11:13 206阅读 0赞

std::string UrlEncode(const std::string& szToEncode)
    {
    	std::string src = szToEncode;
    	char hex[] = "0123456789ABCDEF";
    	string dst;
    
    
    	for (size_t i = 0; i < src.size(); ++i)
    	{
    		unsigned char cc = src[i];
    		if ( cc >= 'A' && cc <= 'Z' 
                     || cc >='a' && cc <= 'z'
                     || cc >='0' && cc <= '9'
                     || cc == '.'
                     || cc == '_'
                     || cc == '-'
                     || cc == '*')
    		{
    			if (cc == ' ')
    			{
    				dst += "+";
    			}
    			else
    				dst += cc;
    		}
    		else
    		{
    			unsigned char c = static_cast<unsigned char>(src[i]);
    			dst += '%';
    			dst += hex[c / 16];
    			dst += hex[c % 16];
    		}
    	}
    	return dst;
    }

std::string UrlDecode(const std::string& szToDecode)
    {
    	std::string result;
    	int hex = 0;
    	for (size_t i = 0; i < szToDecode.length(); ++i)
    	{
    		switch (szToDecode[i])
    		{
    		case '+':
    			result += ' ';
    			break;
    		case '%':
    			if (isxdigit(szToDecode[i + 1]) && isxdigit(szToDecode[i + 2]))
    			{
    				std::string hexStr = szToDecode.substr(i + 1, 2);
    				hex = strtol(hexStr.c_str(), 0, 16);
    				//字母和数字[0-9a-zA-Z]、一些特殊符号[$-_.+!*'(),] 、以及某些保留字[$&+,/:;=?@]
    				//可以不经过编码直接用于URL
    				if (!((hex >= 48 && hex <= 57) ||	//0-9
    					(hex >=97 && hex <= 122) ||	//a-z
    					(hex >=65 && hex <= 90) ||	//A-Z
    					//一些特殊符号及保留字[$-_.+!*'(),]  [$&+,/:;=?@]
    					hex == 0x21 || hex == 0x24 || hex == 0x26 || hex == 0x27 || hex == 0x28 || hex == 0x29
    					|| hex == 0x2a || hex == 0x2b|| hex == 0x2c || hex == 0x2d || hex == 0x2e || hex == 0x2f
    					|| hex == 0x3A || hex == 0x3B|| hex == 0x3D || hex == 0x3f || hex == 0x40 || hex == 0x5f
    					))
    				{
    					result += char(hex);
    					i += 2;
    				}
    				else result += '%';
    			}else {
    				result += '%';
    			}
    			break;
    		default:
    			result += szToDecode[i];
    			break;
    		}
    	}
    	return result;
    }