content: package com.alimama.mdrill.distinct;
  
  import java.nio.charset.Charset;
  
  public class ByteUtil
  {
      public static byte[] getBytes(short data)
      {
          byte[] bytes = new byte[2];
          bytes[0] = (byte) (data & 0xff);
          bytes[1] = (byte) ((data & 0xff00) >> 8);
          return bytes;
      }
  
      public static byte[] getBytes(char data)
      {
          byte[] bytes = new byte[2];
          bytes[0] = (byte) (data);
          bytes[1] = (byte) (data >> 8);
          return bytes;
      }
  
      public static byte[] getBytes(int data)
      {
          byte[] bytes = new byte[4];
          bytes[0] = (byte) (data & 0xff);
          bytes[1] = (byte) ((data & 0xff00) >> 8);
          bytes[2] = (byte) ((data & 0xff0000) >> 16);
          bytes[3] = (byte) ((data & 0xff000000) >> 24);
          return bytes;
      }
  
      public static byte[] getBytes(long data)
      {
          byte[] bytes = new byte[8];
          bytes[0] = (byte) (data & 0xff);
          bytes[1] = (byte) ((data >> 8) & 0xff);
          bytes[2] = (byte) ((data >> 16) & 0xff);
          bytes[3] = (byte) ((data >> 24) & 0xff);
          bytes[4] = (byte) ((data >> 32) & 0xff);
          bytes[5] = (byte) ((data >> 40) & 0xff);
          bytes[6] = (byte) ((data >> 48) & 0xff);
          bytes[7] = (byte) ((data >> 56) & 0xff);
          return bytes;
      }
  
      public static byte[] getBytes(float data)
      {
          int intBits = Float.floatToIntBits(data);
          return getBytes(intBits);
      }
  
      public static byte[] getBytes(double data)
      {
          long intBits = Double.doubleToLongBits(data);
          return getBytes(intBits);
      }
  
      public static byte[] getBytes(String data, String charsetName)
      {
          Charset charset = Charset.forName(charsetName);
          return data.getBytes(charset);
      }
  
      public static byte[] getBytes(String data)
      {
          return getBytes(data, "GBK");
      }
  
      
      public static short getShort(byte[] bytes)
      {
          return (short) ((0xff & bytes[0]) | (0xff00 & (bytes[1] << 8)));
      }
  
      public static char getChar(byte[] bytes)
      {
          return (char) ((0xff & bytes[0]) | (0xff00 & (bytes[1] << 8)));
      }
  
      public static int getInt(byte[] bytes)
      {
          return (0xff & bytes[0]) | (0xff00 & (bytes[1] << 8)) | (0xff0000 & (bytes[2] << 16)) | (0xff000000 & (bytes[3] << 24));
      }
     
      public static long getLong(byte[] bytes)
      {
          return(0xffL & (long)bytes[0]) | (0xff00L & ((long)bytes[1] << 8)) | (0xff0000L & ((long)bytes[2] << 16)) | (0xff000000L & ((long)bytes[3] << 24))
           | (0xff00000000L & ((long)bytes[4] << 32)) | (0xff0000000000L & ((long)bytes[5] << 40)) | (0xff000000000000L & ((long)bytes[6] << 48)) | (0xff00000000000000L & ((long)bytes[7] << 56));
      }
  
      public static float getFloat(byte[] bytes)
      {
          return Float.intBitsToFloat(getInt(bytes));
      }
  
      public static double getDouble(byte[] bytes)
      {
          long l = getLong(bytes);
          System.out.println(l);
          return Double.longBitsToDouble(l);
      }
      
  }
  