byte，int互转

bytes to int

//只能转高位开始 
public static int byteArrayToInt(byte[] b) {
   int value= 0;
   for (int i = 0; i < 4; i++) {
       int shift= (4 - 1 - i) * 8;
       value +=(b[i] & 0x000000FF) << shift;
    }
      return value;
}


int to bytes


public static byte[] intToByteArray1(int i) { 
  
    byte[] result = new byte[4];   
    result[0] = (byte)((i >> 24) & 0xFF);
    result[1] = (byte)((i >> 16) & 0xFF);
    result[2] = (byte)((i >> 8) & 0xFF); 
    result[3] = (byte)(i & 0xFF);
    return result;
}