JAVA:MD5加密器

答案：package creator.common.key;

import java.lang.reflect.*;
/*************************************************
keyBean 类实现了RSA Data Security, Inc.在提交给IETF
的RFC1321中的keyBean message-digest 算法。
*************************************************/

public class keyBean {
        /* 下面这些S11-S44实际上是一个4*4的矩阵，在原始的C实现中是用#define 实现的，
        这里把它们实现成为static final是表示了只读，切能在同一个进程空间内的多个
        Instance间共享*/
        static final int S11 = 7;
        static final int S12 = 12;
        static final int S13 = 17;
        static final int S14 = 22;

        static final int S21 = 5;
        static final int S22 = 9;
        static final int S23 = 14;
        static final int S24 = 20;

        static final int S31 = 4;
        static final int S32 = 11;
        static final int S33 = 16;
        static final int S34 = 23;

        static final int S41 = 6;
        static final int S42 = 10;
        static final int S43 = 15;
        static final int S44 = 21;

        static final byte[] PADDING = { -128, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
        /* 下面的三个成员是keyBean计算过程中用到的3个核心数据，在原始的C实现中
           被定义到keyBean_CTX结构中

         */
        private long[] state = new long[4];  // state (ABCD)
        private long[] count = new long[2];  // number of bits, modulo 2^64 (lsb first)
        private byte[] buffer = new byte[64]; // input buffer

        /* digestHexStr是keyBean的唯一一个公共成员，是最新一次计算结果的
        　 16进制ASCII表示.
        */
        public String digestHexStr;

        /* digest,是最新一次计算结果的2进制内部表示，表示128bit的keyBean值.
        */
        private byte[] digest = new byte[16];

        /*
          getkeyBeanofStr是类keyBean最主要的公共方法，入口参数是你想要进行keyBean变换的字符串
          返回的是变换完的结果，这个结果是从公共成员digestHexStr取得的．
        */
        public String getkeyBeanofStr(String inbuf) {
                keyBeanInit();
                keyBeanUpdate(inbuf.getBytes(), inbuf.length());
                keyBeanFinal();
                digestHexStr = "";
                for (int i = 0; i < 16; i++) {
                        digestHexStr += byteHEX(digest[i]);
                }
                return digestHexStr;

        }
        // 这是keyBean这个类的标准构造函数，JavaBean要求有一个public的并且没有参数的构造函数
        public keyBean() {
                keyBeanInit();

                return;
        }


        /* keyBeanInit是一个初始化函数，初始化核心变量，装入标准的幻数 */
        private void keyBeanInit() {
                count[0] = 0L;
                count[1] = 0L;
                ///* Load magic initialization constants.

                state[0] = 0x67452301L;
                state[1] = 0xefcdab89L;
                state[2] = 0x98badcfeL;
                state[3] = 0x10325476L;

                return;
        }
        /* F, G, H ,I 是4个基本的keyBean函数，在原始的keyBean的C实现中，由于它们是
        简单的位运算，可能出于效率的考虑把它们实现成了宏，在java中，我们把它们
     　　实现成了private方法，名字保持了原来C中的。 */

        private long F(long x, long y, long z) {
                return (x & y) | ((~x) & z);

        }
        private long G(long x, long y, long z) {
                return (x & z) | (y & (~z));

        }
        private long H(long x, long y, long z) {
                return x ^ y ^ z;
        }

        private long I(long x, long y, long z) {
                return y ^ (x | (~z));
        }

       /*
          FF,GG,HH和II将调用F,G,H,I进行近一步变换
          FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
          Rotation is separate from addition to prevent recomputation.
       */

        private long FF(long a, long b, long c, long d, long x, long s,
                long ac) {
                a += F (b, c, d) + x + ac;
                a = ((int) a << s) | ((int) a >>> (32 - s));
                a += b;
                return a;
        }

        private long GG(long a, long b, long c, long d, long x, long s,
                long ac) {
                a += G (b, c, d) + x + ac;
                a = ((int) a << s) | ((int) a >>> (32 - s));
                a += b;
                return a;
        }
        private long HH(long a, long b, long c, long d, long x, long s,
                long ac) {
                a += H (b, c, d) + x + ac;
                a = ((int) a << s) | ((int) a >>> (32 - s));
                a += b;
                return a;
        }
        private long II(long a, long b, long c, long d, long x, long s,
                long ac) {
                a += I (b, c, d) + x + ac;
                a = ((int) a << s) | ((int) a >>> (32 - s));
                a += b;
                return a;
        }
        /*
         keyBeanUpdate是keyBean的主计算过程，inbuf是要变换的字节串，inputlen是长度，这个
         函数由getkeyBeanofStr调用，调用之前需要调用keyBeaninit，因此把它设计成private的
        */
        private void keyBeanUpdate(byte[] inbuf, int inputLen) {

                int i, index, partLen;
                byte[] block = new byte[64];
                index = (int)(count[0] >>> 3) & 0x3F;
                // /* Update number of bits */
                if ((count[0] += (inputLen << 3)) < (inputLen << 3))
                        count[1]++;
                count[1] += (inputLen >>> 29);

                partLen = 64 - index;

                // Transform as many times as possible.
                if (inputLen >= partLen) {
                        keyBeanMemcpy(buffer, inbuf, index, 0, partLen);
                        keyBeanTransform(buffer);

                        for (i = partLen; i + 63 < inputLen; i += 64) {

                                keyBeanMemcpy(block, inbuf, 0, i, 64);
                                keyBeanTransform (block);
                        }
                        index = 0;

                } else

                        i = 0;

                ///* Buffer remaining input */
                keyBeanMemcpy(buffer, inbuf, index, i, inputLen - i);

        }

        /*
          keyBeanFinal整理和填写输出结果
        */
        private void keyBeanFinal () {
                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);
                keyBeanUpdate (PADDING, padLen);

                ///* Append length (before padding) */
                keyBeanUpdate(bits, 8);

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

        }

        /* keyBeanMemcpy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 keyBeanMemcpy (byte[] output, byte[] input,
                int 

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