Java的类库支持完全不如C#，比如时间类，比如数据类型转换类等等，难道是我自己没找到吗？

下面是字节转换类，byte[]与short, int, long, float, double, String相互转换；网络字节序htons, htonl等实现；byte[]转十六进制字符串、二进制字符串实现。

希望对朋友有用，如果有更好的方法，请提醒我。

public class ByteUtil {      /**      * 转换short为byte      *       * @param b      * @param s      *            需要转换的short      * @param index      */      public static void putShort(byte b[], short s, int index) {          b[index + 1] = (byte) (s >> 8);          b[index + 0] = (byte) (s >> 0);      }        /**      * 通过byte数组取到short      *       * @param b      * @param index      *            第几位开始取      * @return      */      public static short getShort(byte[] b, int index) {          return (short) (((b[index + 1] << 8) | b[index + 0] & 0xff));      }        /**      * 转换int为byte数组      *       * @param bb      * @param x      * @param index      */      public static void putInt(byte[] bb, int x, int index) {          bb[index + 3] = (byte) (x >> 24);          bb[index + 2] = (byte) (x >> 16);          bb[index + 1] = (byte) (x >> 8);          bb[index + 0] = (byte) (x >> 0);      }        /**      * 通过byte数组取到int      *       * @param bb      * @param index      *            第几位开始      * @return      */      public static int getInt(byte[] bb, int index) {          return (int) ((((bb[index + 3] & 0xff) << 24)                  | ((bb[index + 2] & 0xff) << 16)                  | ((bb[index + 1] & 0xff) << 8) | ((bb[index + 0] & 0xff) << 0)));      }        /**      * 转换long型为byte数组      *       * @param bb      * @param x      * @param index      */      public static void putLong(byte[] bb, long x, int index) {          bb[index + 7] = (byte) (x >> 56);          bb[index + 6] = (byte) (x >> 48);          bb[index + 5] = (byte) (x >> 40);          bb[index + 4] = (byte) (x >> 32);          bb[index + 3] = (byte) (x >> 24);          bb[index + 2] = (byte) (x >> 16);          bb[index + 1] = (byte) (x >> 8);          bb[index + 0] = (byte) (x >> 0);      }        /**      * 通过byte数组取到long      *       * @param bb      * @param index      * @return      */      public static long getLong(byte[] bb, int index) {          return ((((long) bb[index + 7] & 0xff) << 56)                  | (((long) bb[index + 6] & 0xff) << 48)                  | (((long) bb[index + 5] & 0xff) << 40)                  | (((long) bb[index + 4] & 0xff) << 32)                  | (((long) bb[index + 3] & 0xff) << 24)                  | (((long) bb[index + 2] & 0xff) << 16)                  | (((long) bb[index + 1] & 0xff) << 8) | (((long) bb[index + 0] & 0xff) << 0));      }        /**      * 字符到字节转换      *       * @param ch      * @return      */      public static void putChar(byte[] bb, char ch, int index) {          int temp = (int) ch;          // byte[] b = new byte[2];           for (int i = 0; i < 2; i ++ ) {              bb[index + i] = new Integer(temp & 0xff).byteValue(); // 将最高位保存在最低位               temp = temp >> 8; // 向右移8位           }      }        /**      * 字节到字符转换      *       * @param b      * @return      */      public static char getChar(byte[] b, int index) {          int s = 0;          if (b[index + 1] > 0)              s += b[index + 1];          else              s += 256 + b[index + 0];          s *= 256;          if (b[index + 0] > 0)              s += b[index + 1];          else              s += 256 + b[index + 0];          char ch = (char) s;          return ch;      }        /**      * float转换byte      *       * @param bb      * @param x      * @param index      */      public static void putFloat(byte[] bb, float x, int index) {          // byte[] b = new byte[4];           int l = Float.floatToIntBits(x);          for (int i = 0; i < 4; i++) {              bb[index + i] = new Integer(l).byteValue();              l = l >> 8;          }      }        /**      * 通过byte数组取得float      *       * @param bb      * @param index      * @return      */      public static float getFloat(byte[] b, int index) {          int l;          l = b[index + 0];          l &= 0xff;          l |= ((long) b[index + 1] << 8);          l &= 0xffff;          l |= ((long) b[index + 2] << 16);          l &= 0xffffff;          l |= ((long) b[index + 3] << 24);          return Float.intBitsToFloat(l);      }        /**      * double转换byte      *       * @param bb      * @param x      * @param index      */      public static void putDouble(byte[] bb, double x, int index) {          // byte[] b = new byte[8];           long l = Double.doubleToLongBits(x);          for (int i = 0; i < 8; i++) {              bb[index + i] = new Long(l).byteValue();              l = l >> 8;          }      }        /**      * 通过byte数组取得double      *       * @param bb      * @param index      * @return      */      public static double getDouble(byte[] b, int index) {          long l;          l = b[0];          l &= 0xff;          l |= ((long) b[1] << 8);          l &= 0xffff;          l |= ((long) b[2] << 16);          l &= 0xffffff;          l |= ((long) b[3] << 24);          l &= 0xffffffffl;          l |= ((long) b[4] << 32);          l &= 0xffffffffffl;          l |= ((long) b[5] << 40);          l &= 0xffffffffffffl;          l |= ((long) b[6] << 48);          l &= 0xffffffffffffffl;          l |= ((long) b[7] << 56);          return Double.longBitsToDouble(l);      }      public static void putHexString(byte[] bb, String s, int index){        for (int i = 0; i < s.length(); i+=2) {            byte c= (byte)( charToByte(s.charAt(i))<<4 | charToByte(s.charAt(i+1)));            bb[index+(i>>1)] = c;        }    }    private static byte charToByte(char c) {           return (byte) "0123456789ABCDEF".indexOf(c);       }         public static String getHexString(byte[] b, int index, int count){           StringBuilder stringBuilder = new StringBuilder("");           if (b == null || index < 0 || b.length < index + count ) {               return null;           }           for (int i = index; i < count + index; i++) {               int v = b[i] & 0xFF;               String hv = Integer.toHexString(v);               if (hv.length() < 2) {                   stringBuilder.append(0);               }               stringBuilder.append(hv);           }           return stringBuilder.toString();       }          public static String getBinaryString(int d,int length){        StringBuilder stringBuilder = new StringBuilder("");         String hv = Integer.toBinaryString(d);           for (int j = 0; j < length - hv.length(); j++) {            stringBuilder.append(0);        }         stringBuilder.append(hv);         return stringBuilder.toString();      }        public static String getBinaryReverseString(int d,int length){        StringBuilder stringBuilder = new StringBuilder("");         String hv = Integer.toBinaryString(d);           for (int j = 0; j < length - hv.length(); j++) {            stringBuilder.append(0);        }         stringBuilder.append(hv);         stringBuilder.reverse();                return stringBuilder.toString();     }        //网络字节逆序    public static byte[] ReversEndian(byte b[],int count, boolean big)    {       byte by;       byte data[] = new byte[count];       for(int i=0;i