md5.java

通过apache 的jxl中件间,实现excel文件的导入导出的小例子

        byte[] bits = new byte[8];
        int index, padLen;

        // Save number of bits
        Encode(bits, count, 8);

        // Pad out to 56 mod 64.
        index = (int) (count[0] >>> 3) & 0x3f;
        padLen = (index < 56) ? (56 - index) : (120 - index);
        md5Update(PADDING, padLen);

        // Append length (before padding)
        md5Update(bits, 8);

        // Store state in digest
        Encode(digest, state, 16);
    }


    /**
     * md5Memcpy是一个内部使用的byte数组的块拷贝函数，从input的inpos开始把len长度的
     * 字节拷贝到output的outpos位置开始
     */
    private void md5Memcpy(byte[] output, byte[] input, int outpos, int inpos,
                           int len) {
        int i;

        for (i = 0; i < len; i++) {
            output[outpos + i] = input[inpos + i];
        }
    }


    /**
     * md5Transform是MD5核心变换程序，有md5Update调用，block是分块的原始字节
     */
    private void md5Transform(byte block[]) {
        long a = state[0], b = state[1], c = state[2], d = state[3];
        long[] x = new long[16];

        Decode(x, block, 64);

        /* Round 1 */
        a = FF(a, b, c, d, x[0], S11, 0xd76aa478L); /* 1 */
        d = FF(d, a, b, c, x[1], S12, 0xe8c7b756L); /* 2 */
        c = FF(c, d, a, b, x[2], S13, 0x242070dbL); /* 3 */
        b = FF(b, c, d, a, x[3], S14, 0xc1bdceeeL); /* 4 */
        a = FF(a, b, c, d, x[4], S11, 0xf57c0fafL); /* 5 */
        d = FF(d, a, b, c, x[5], S12, 0x4787c62aL); /* 6 */
        c = FF(c, d, a, b, x[6], S13, 0xa8304613L); /* 7 */
        b = FF(b, c, d, a, x[7], S14, 0xfd469501L); /* 8 */
        a = FF(a, b, c, d, x[8], S11, 0x698098d8L); /* 9 */
        d = FF(d, a, b, c, x[9], S12, 0x8b44f7afL); /* 10 */
        c = FF(c, d, a, b, x[10], S13, 0xffff5bb1L); /* 11 */
        b = FF(b, c, d, a, x[11], S14, 0x895cd7beL); /* 12 */
        a = FF(a, b, c, d, x[12], S11, 0x6b901122L); /* 13 */
        d = FF(d, a, b, c, x[13], S12, 0xfd987193L); /* 14 */
        c = FF(c, d, a, b, x[14], S13, 0xa679438eL); /* 15 */
        b = FF(b, c, d, a, x[15], S14, 0x49b40821L); /* 16 */

        /* Round 2 */
        a = GG(a, b, c, d, x[1], S21, 0xf61e2562L); /* 17 */
        d = GG(d, a, b, c, x[6], S22, 0xc040b340L); /* 18 */
        c = GG(c, d, a, b, x[11], S23, 0x265e5a51L); /* 19 */
        b = GG(b, c, d, a, x[0], S24, 0xe9b6c7aaL); /* 20 */
        a = GG(a, b, c, d, x[5], S21, 0xd62f105dL); /* 21 */
        d = GG(d, a, b, c, x[10], S22, 0x2441453L); /* 22 */
        c = GG(c, d, a, b, x[15], S23, 0xd8a1e681L); /* 23 */
        b = GG(b, c, d, a, x[4], S24, 0xe7d3fbc8L); /* 24 */
        a = GG(a, b, c, d, x[9], S21, 0x21e1cde6L); /* 25 */
        d = GG(d, a, b, c, x[14], S22, 0xc33707d6L); /* 26 */
        c = GG(c, d, a, b, x[3], S23, 0xf4d50d87L); /* 27 */
        b = GG(b, c, d, a, x[8], S24, 0x455a14edL); /* 28 */
        a = GG(a, b, c, d, x[13], S21, 0xa9e3e905L); /* 29 */
        d = GG(d, a, b, c, x[2], S22, 0xfcefa3f8L); /* 30 */
        c = GG(c, d, a, b, x[7], S23, 0x676f02d9L); /* 31 */
        b = GG(b, c, d, a, x[12], S24, 0x8d2a4c8aL); /* 32 */

        /* Round 3 */
        a = HH(a, b, c, d, x[5], S31, 0xfffa3942L); /* 33 */
        d = HH(d, a, b, c, x[8], S32, 0x8771f681L); /* 34 */
        c = HH(c, d, a, b, x[11], S33, 0x6d9d6122L); /* 35 */
        b = HH(b, c, d, a, x[14], S34, 0xfde5380cL); /* 36 */
        a = HH(a, b, c, d, x[1], S31, 0xa4beea44L); /* 37 */
        d = HH(d, a, b, c, x[4], S32, 0x4bdecfa9L); /* 38 */
        c = HH(c, d, a, b, x[7], S33, 0xf6bb4b60L); /* 39 */
        b = HH(b, c, d, a, x[10], S34, 0xbebfbc70L); /* 40 */
        a = HH(a, b, c, d, x[13], S31, 0x289b7ec6L); /* 41 */
        d = HH(d, a, b, c, x[0], S32, 0xeaa127faL); /* 42 */
        c = HH(c, d, a, b, x[3], S33, 0xd4ef3085L); /* 43 */
        b = HH(b, c, d, a, x[6], S34, 0x4881d05L); /* 44 */
        a = HH(a, b, c, d, x[9], S31, 0xd9d4d039L); /* 45 */
        d = HH(d, a, b, c, x[12], S32, 0xe6db99e5L); /* 46 */
        c = HH(c, d, a, b, x[15], S33, 0x1fa27cf8L); /* 47 */
        b = HH(b, c, d, a, x[2], S34, 0xc4ac5665L); /* 48 */

        /* Round 4 */
        a = II(a, b, c, d, x[0], S41, 0xf4292244L); /* 49 */
        d = II(d, a, b, c, x[7], S42, 0x432aff97L); /* 50 */
        c = II(c, d, a, b, x[14], S43, 0xab9423a7L); /* 51 */
        b = II(b, c, d, a, x[5], S44, 0xfc93a039L); /* 52 */
        a = II(a, b, c, d, x[12], S41, 0x655b59c3L); /* 53 */
        d = II(d, a, b, c, x[3], S42, 0x8f0ccc92L); /* 54 */
        c = II(c, d, a, b, x[10], S43, 0xffeff47dL); /* 55 */
        b = II(b, c, d, a, x[1], S44, 0x85845dd1L); /* 56 */
        a = II(a, b, c, d, x[8], S41, 0x6fa87e4fL); /* 57 */
        d = II(d, a, b, c, x[15], S42, 0xfe2ce6e0L); /* 58 */
        c = II(c, d, a, b, x[6], S43, 0xa3014314L); /* 59 */
        b = II(b, c, d, a, x[13], S44, 0x4e0811a1L); /* 60 */
        a = II(a, b, c, d, x[4], S41, 0xf7537e82L); /* 61 */
        d = II(d, a, b, c, x[11], S42, 0xbd3af235L); /* 62 */
        c = II(c, d, a, b, x[2], S43, 0x2ad7d2bbL); /* 63 */
        b = II(b, c, d, a, x[9], S44, 0xeb86d391L); /* 64 */

        state[0] += a;
        state[1] += b;
        state[2] += c;
        state[3] += d;
    }


    /**
     * Encode把long数组按顺序拆成byte数组，因为java的long类型是64bit的，
     * 只拆低32bit，以适应原始C实现的用途
     */
    private void Encode(byte[] output, long[] input, int len) {
        int i, j;

        for (i = 0, j = 0; j < len; i++, j += 4) {
            output[j] = (byte) (input[i] & 0xffL);
            output[j + 1] = (byte) ( (input[i] >>> 8) & 0xffL);
            output[j + 2] = (byte) ( (input[i] >>> 16) & 0xffL);
            output[j + 3] = (byte) ( (input[i] >>> 24) & 0xffL);
        }
    }


    /**
     * Decode把byte数组按顺序合成成long数组，因为java的long类型是64bit的，
     * 只合成低32bit，高32bit清零，以适应原始C实现的用途
     */
    private void Decode(long[] output, byte[] input, int len) {
        int i, j;

        for (i = 0, j = 0; j < len; i++, j += 4) {
            output[i] = b2iu(input[j]) |
                        (b2iu(input[j + 1]) << 8) |
                        (b2iu(input[j + 2]) << 16) |
                        (b2iu(input[j + 3]) << 24);

        }
        return;
    }


    /**
     * b2iu是一个把byte按照不考虑正负号的原则的＂升位＂程序，因为java没有unsigned运算
     */
    public static long b2iu(byte b) {
        return b < 0 ? b & 0x7F + 128 : b;
    }


    /**
     * byteHEX()，用来把一个byte类型的数转换成十六进制的ASCII表示，
     * 因为java中的byte的toString无法实现这一点，我们又没有C语言中的
     * sprintf(outbuf,"%02X",ib)
     */
    public static String byteHEX(byte ib) {
        char[] Digit = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                       'A', 'B', 'C', 'D', 'E', 'F'};

        char[] ob = new char[2];
        ob[0] = Digit[ (ib >>> 4) & 0X0F];
        ob[1] = Digit[ib & 0X0F];
        String s = new String(ob);

        return s;
    }


    public static void main(String args[]) {
        MD5 m = new MD5();
        if (Array.getLength(args) == 0) {
            //如果没有参数，执行标准的Test Suite
            System.out.println("MD5 Test suite:");
            System.out.println("MD5(\"\"): " + m.getMD5ofStr(""));
            System.out.println("MD5(\"a\"): " + m.getMD5ofStr("a"));
            System.out.println("MD5(\"abc\"): " + m.getMD5ofStr("abc"));
            System.out.println("MD5(\"1\"): " + m.getMD5ofStr("1"));
            System.out.println("MD5(\"2\"): " + m.getMD5ofStr("2"));
            System.out.println("MD5(\"3\"): " + m.getMD5ofStr("3"));
            System.out.println("MD5(\"4\"): " + m.getMD5ofStr("4"));
            System.out.println("MD5(\"5\"): " + m.getMD5ofStr("5"));
            System.out.println("MD5(\"6\"): " + m.getMD5ofStr("6"));
            System.out.println("MD5(\"101\"): " + m.getMD5ofStr("101"));
            System.out.println("MD5(\"102\"): " + m.getMD5ofStr("102"));
            System.out.println("MD5(\"103\"): " + m.getMD5ofStr("103"));
            System.out.println("MD5(\"1001\"): " + m.getMD5ofStr("1001"));
            
            System.out.println("MD5(\"wang2bd1984128\"): " + m.getMD5ofStr("wang2bd1984128"));
            
            System.out.println("MD5(\"message digest\"): " +
                               m.getMD5ofStr("message digest"));
            System.out.println("MD5(\"abcdefghijklmnopqrstuvwxyz\"): " +
                               m.getMD5ofStr("abcdefghijklmnopqrstuvwxyz"));
            System.out.println(
                "MD5(\"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789\"): " +
                m.getMD5ofStr(
                "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"));
            System.out.println("MD5(\"admin\"): " + m.getMD5ofStr("admin"));
        } else {
            System.out.println("MD5(" + args[0] + ")=" + m.getMD5ofStr(args[0]));
        }
    }

}