QT Base64 编解码

来源：互联网发布：国家顶级域名编辑：程序博客网时间：2024/05/20 21:57

#ifndef BASE64_H#define BASE64_H #include <QString> class Base64{public:    /*     * 功能：静态成员函数，将字节数组转换为Base64编码字符串     * 参数说明：     *      binaryData：要转换的字节数组     * 返回值：     *      转换后得到的Base64编码字符串     * 异常抛出：     *      无     * 说明：     *      空说明列表指出函数不抛出任何异常     *      如果一个函数声明没有指定异常说明，则该函数可以抛出任意类型的异常     */    static QString encode(const QByteArray & binaryData) throw();     /*     * 功能：静态成员函数，将Base64编码字符串解码为字节数组     * 参数说明：     *      base64String：要转换的Base64编码字符串     * 返回值：     *      解码后得到的字节数组     * 异常抛出：     *      抛出整型异常     *          -1：数据错误     * 说明：     *      字符串中允许任意的空白字符、回车换行符、连字符     */    static QByteArray decode(const QString & base64String) throw(int);}; #endif // BASE64_H

#include "Base64.h"#include <QDataStream> static const char* DATA_BIN2ASCII = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; // Base64编码，该函数不抛出任何异常QString Base64::encode(const QByteArray & binaryData) throw(){    if(binaryData.isEmpty())return QString();     QString sb;    int index = 0;    for(int i = binaryData.length(); i > 0; i -= 3)    {   // 将3字节数据转换成4个ASCII字符        if(i >= 3)        {            int b0 = binaryData[index++] & 0xFF;            int b1 = binaryData[index++] & 0xFF;            int b2 = binaryData[index++] & 0xFF;            sb.append(DATA_BIN2ASCII[b0 >> 2]);            sb.append(DATA_BIN2ASCII[((b0 << 4) | (b1 >> 4)) & 0x3F]);            sb.append(DATA_BIN2ASCII[((b1 << 2) | (b2 >> 6)) & 0x3F]);            sb.append(DATA_BIN2ASCII[b2 & 0x3F]);        }        else        {            int b0 = binaryData[index++] & 0xFF;            int b1;            if(i == 2)                b1 = binaryData[index++] & 0xFF;            else                b1 = 0;             sb.append(DATA_BIN2ASCII[b0 >> 2]);            sb.append(DATA_BIN2ASCII[((b0 << 4) | (b1 >> 4)) & 0x3F]);            if(i == 1)                sb.append('='); // 填充字符            else                sb.append(DATA_BIN2ASCII[(b1 << 2) & 0x3F]);            sb.append('=');     // 填充字符        }    }     return sb;} #define B64_EOLN            0xF0    // 换行\n#define B64_CR              0xF1    // 回车\r#define B64_EOF             0xF2    // 连字符-#define B64_WS              0xE0    // 跳格或者空格（\t、space）#define B64_ERROR           0xFF    // 错误字符#define B64_NOT_BASE64      0xF3    // 空白字符、回车换行字符、连字符 static const quint8 DATA_ASCII2BIN[128] = {    0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xE0,0xF0,0xFF,0xFF,0xF1,0xFF,0xFF,    0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,    0xE0,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x3E,0xFF,0xF2,0xFF,0x3F,    0x34,0x35,0x36,0x37,0x38,0x39,0x3A,0x3B,0x3C,0x3D,0xFF,0xFF,0xFF,0x00,0xFF,0xFF,    0xFF,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,    0x0F,0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0xFF,0xFF,0xFF,0xFF,0xFF,    0xFF,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,    0x29,0x2A,0x2B,0x2C,0x2D,0x2E,0x2F,0x30,0x31,0x32,0x33,0xFF,0xFF,0xFF,0xFF,0xFF}; // Base64解码，该函数抛出整型异常QByteArray Base64::decode(const QString & base64String) throw(int){    if(base64String.isEmpty()) return QByteArray();     int length = base64String.length(); // 字符串长度    QByteArray ba;  // 字节数组    QDataStream out(&ba, QIODevice::WriteOnly); // 写入数据流     int index = 0;    int previous = 0;    for(int i = 0; i < length; i++)    {        int charValue = base64String[i].unicode();  // 字符的Unicode编码        if(charValue >= 0x80) throw(-1); // 数据错误          int orderValue = DATA_ASCII2BIN[charValue];        if(orderValue == B64_ERROR) throw(-1); // 数据错误         // 跳过空白字符、回车换行字符、连字符        if((orderValue | 0x13) == B64_NOT_BASE64)            continue;         if(index == 0)        {            if(charValue == '=') throw(-1); // 数据错误             previous = orderValue;            index++;        }        else if(index == 1)        {            if(charValue == '=') throw(-1); // 数据错误             out << static_cast<quint8>((previous << 2) | (orderValue >> 4));            previous = orderValue;            index++;        }        else if(index == 2)        {            if(charValue == '=')            {   // 简化处理，不再判断第二个'='                index = 0;                break;            }             out << static_cast<quint8>((previous << 4) | (orderValue >> 2));            previous = orderValue;            index++;        }        else        {            index = 0;            if(charValue == '=')break;             out << static_cast<quint8>((previous << 6) | orderValue);        }    } // End for     if(index == 0)  // 有效字符个数必须是4的倍数        return ba;    else        throw(-1);  // 数据错误}

阅读全文

0 0