/**
* 通信格式轉換
*
* Java和一些windows編程語言如c、c++、Delphi所寫的網絡程序進行通訊時，需要進行相應的轉換
* 高、低字節之間的轉換
* windows的字節序為低字節開頭
* linux,unix的字節序為高字節開頭
* java則無論平臺變化，都是高字節開頭
  */

public class FormatTransfer {
/**
  * 將int轉為低字節在前，高字節在后的byte數組
  * @param n int
  * @return byte[]
  */
public static byte[] toLH(int n) {
  byte[] b = new byte[4];
  b[0] = (byte) (n & 0xff);
  b[1] = (byte) (n >> 8 & 0xff);
  b[2] = (byte) (n >> 16 & 0xff);
  b[3] = (byte) (n >> 24 & 0xff);
  return b;
}

/**
  * 將int轉為高字節在前，低字節在后的byte數組
  * @param n int
  * @return byte[]
  */
public static byte[] toHH(int n) {
  byte[] b = new byte[4];
  b[3] = (byte) (n & 0xff);
  b[2] = (byte) (n >> 8 & 0xff);
  b[1] = (byte) (n >> 16 & 0xff);
  b[0] = (byte) (n >> 24 & 0xff);
  return b;
}

/**
  * 將short轉為低字節在前，高字節在后的byte數組
  * @param n short
  * @return byte[]
  */
public static byte[] toLH(short n) {
  byte[] b = new byte[2];
  b[0] = (byte) (n & 0xff);
  b[1] = (byte) (n >> 8 & 0xff);
  return b;
}

/**
  * 將short轉為高字節在前，低字節在后的byte數組
  * @param n short
  * @return byte[]
  */
public static byte[] toHH(short n) {
  byte[] b = new byte[2];
  b[1] = (byte) (n & 0xff);
  b[0] = (byte) (n >> 8 & 0xff);
  return b;
}

/**
  * 將將int轉為高字節在前，低字節在后的byte數組

public static byte[] toHH(int number) {
  int temp = number;
  byte[] b = new byte[4];
  for (int i = b.length - 1; i > -1; i--) {
    b = new Integer(temp & 0xff).byteValue();
    temp = temp >> 8;
  }
  return b;
}

public static byte[] IntToByteArray(int i) {
    byte[] abyte0 = new byte[4];
    abyte0[3] = (byte) (0xff & i);
    abyte0[2] = (byte) ((0xff00 & i) >> 8);
    abyte0[1] = (byte) ((0xff0000 & i) >> 16);
    abyte0[0] = (byte) ((0xff000000 & i) >> 24);
    return abyte0;
}

*/

/**
  * 將float轉為低字節在前，高字節在后的byte數組
  */
public static byte[] toLH(float f) {

  return toLH(Float.floatToRawIntBits(f));
}

/**
  * 將float轉為高字節在前，低字節在后的byte數組
  */
public static byte[] toHH(float f) {
  return toHH(Float.floatToRawIntBits(f));
}

/**
  * 將String轉為byte數組
  */
public static byte[] stringToBytes(String s, int length) {
  while (s.getBytes().length < length) {
    s += " ";
  }
  return s.getBytes();
}

/**
  * 將字節數組轉換為String
  * @param b byte[]
  * @return String
  */
public static String bytesToString(byte[] b) {
  StringBuffer result = new StringBuffer("");
  int length = b.length;
  for (int i=0; i<length; i++) {
    result.append((char)(b & 0xff));
  }
  return result.toString();
}

/**
  * 將字符串轉換為byte數組
  * @param s String
  * @return byte[]
  */
public static byte[] stringToBytes(String s) {
  return s.getBytes();
}

/**
  * 將高字節數組轉換為int
  * @param b byte[]
  * @return int
  */
public static int hBytesToInt(byte[] b) {
  int s = 0;
  for (int i = 0; i < 3; i++) {
    if (b >= 0) {
    s = s + b;
    } else {
    s = s + 256 + b;
    }
    s = s * 256;
  }
  if (b[3] >= 0) {
    s = s + b[3];
  } else {
    s = s + 256 + b[3];
  }
  return s;
}

/**
  * 將低字節數組轉換為int
  * @param b byte[]
  * @return int
  */
public static int lBytesToInt(byte[] b) {
  int s = 0;
  for (int i = 0; i < 3; i++) {
    if (b[3-i] >= 0) {
    s = s + b[3-i];
    } else {
    s = s + 256 + b[3-i];
    }
    s = s * 256;
  }
  if (b[0] >= 0) {
    s = s + b[0];
  } else {
    s = s + 256 + b[0];
  }
  return s;
}

/**
  * 高字節數組到short的轉換
  * @param b byte[]
  * @return short
  */
public static short hBytesToShort(byte[] b) {
  int s = 0;
  if (b[0] >= 0) {
    s = s + b[0];
    } else {
    s = s + 256 + b[0];
    }
    s = s * 256;
  if (b[1] >= 0) {
    s = s + b[1];
  } else {
    s = s + 256 + b[1];
  }
  short result = (short)s;
  return result;
}

/**
  * 低字節數組到short的轉換
  * @param b byte[]
  * @return short
  */
public static short lBytesToShort(byte[] b) {
  int s = 0;

  if (b[1] >= 0) {
    s = s + b[1];
    } else {
    s = s + 256 + b[1];
    }
    s = s * 256;
  if (b[0] >= 0) {
    s = s + b[0];
  } else {
    s = s + 256 + b[0];
  }
  short result = (short)s;
  return result;
}

/**
  * 高字節數組轉換為float
  * @param b byte[]
  * @return float
  */
public static float hBytesToFloat(byte[] b) {
  int i = 0;
  Float F = new Float(0.0);
  i = ((((b[0]&0xff)<<8 (b[1]&0xff))<<8) (b[2]&0xff))<<8 (b[3]&0xff);
  return F.intBitsToFloat(i);
}

/**
  * 低字節數組轉換為float
  * @param b byte[]
  * @return float
  */
public static float lBytesToFloat(byte[] b) {
  int i = 0;
  Float F = new Float(0.0);
  i = ((((b[3]&0xff)<<8 (b[2]&0xff))<<8) (b[1]&0xff))<<8 (b[0]&0xff);
  return F.intBitsToFloat(i);
}

/**
  * 將byte數組中的元素倒序排列
  */
public static byte[] bytesReverSEOrder(byte[] b) {
  int length = b.length;
  byte[] result = new byte[length];
  for(int i=0; i<length; i++) {
    result[length-i-1] = b;
  }
  return result;
}

/**
  * 打印byte數組
  */
public static void PRintBytes(byte[] bb) {
  int length = bb.length;
  for (int i=0; i<length; i++) {
    System.out.print(bb + " ");
  }
  System.out.println("");
}

public static void logBytes(byte[] bb) {
  int length = bb.length;
  String out = "";
  for (int i=0; i<length; i++) {
    out = out + bb + " ";
  }

}

/**
  * 將int類型的值轉換為字節序顛倒過來對應的int值
  * @param i int
  * @return int
  */
public static int reverseInt(int i) {
  int result = FormatTransfer.hBytesToInt(FormatTransfer.toLH(i));
  return result;
}

/**
  * 將short類型的值轉換為字節序顛倒過來對應的short值
  * @param s short
  * @return short
  */
public static short reverseShort(short s) {
  short result = FormatTransfer.hBytesToShort(FormatTransfer.toLH(s));
  return result;
}

/**
  * 將float類型的值轉換為字節序顛倒過來對應的float值
  * @param f float
  * @return float
  */
public static float reverseFloat(float f) {
  float result = FormatTransfer.hBytesToFloat(FormatTransfer.toLH(f));
  return result;
}

}