conversion d’octets en int en Java

return ((int)hb << 8) | ((int)lb & 0xFF); 

Le bon fonctionnement dans tous les cas rest un exercice pour l’élève.

Vous pouvez également utiliser la classe ByteBuffer :

 public int toInt(byte hb, byte lb) { ByteBuffer bb = ByteBuffer.wrap(new byte[] {hb, lb}); return bb.getShort(); // Implicitly widened to an int per JVM spec. } 

Cette classe peut être utile si vous décodez beaucoup de données.

Usage:

 public class Test { public static void main(Ssortingng[] args) { byte[] b = new byte[] { -83, 0, 0, 0 }; int i = GattUtils.getIntValue(b, GattUtils.FORMAT_UINT32, 0); System.out.println(i); //will print 173 } public class GattUtils { public static final long leastSigBits = 0x800000805f9b34fbL; public static final int FIRST_BITMASK = 0x01; public static final int SECOND_BITMASK = FIRST_BITMASK << 1; public static final int THIRD_BITMASK = FIRST_BITMASK << 2; public static final int FOURTH_BITMASK = FIRST_BITMASK << 3; public static final int FIFTH_BITMASK = FIRST_BITMASK << 4; public static final int SIXTH_BITMASK = FIRST_BITMASK << 5; public static final int SEVENTH_BITMASK = FIRST_BITMASK << 6; public static final int EIGTH_BITMASK = FIRST_BITMASK << 7; public static final int FORMAT_UINT8 = 17; public static final int FORMAT_UINT16 = 18; public static final int FORMAT_UINT32 = 20; public static final int FORMAT_SINT8 = 33; public static final int FORMAT_SINT16 = 34; public static final int FORMAT_SINT32 = 36; public static final int FORMAT_SFLOAT = 50; public static final int FORMAT_FLOAT = 52; public static UUID toUuid(String uuidString) { return UUID.fromString(uuidString); } public static UUID toUuid(long assignedNumber) { return new UUID((assignedNumber << 32) | 0x1000, leastSigBits); } public static String toUuid128(long assignedNumber) { return toUuid(assignedNumber).toString(); } public static String toUuid16(int assignedNumber) { return Integer.toHexString(assignedNumber); } public static Integer getIntValue(byte[] value, int format, int position) { if (value == null) return null; if (position + (format & 0xF) > value.length) return null; switch (format) { case FORMAT_UINT8: return Integer.valueOf(value[position] & 0xFF); case FORMAT_UINT16: return Integer.valueOf(add(value[position], value[(position + 1)])); case FORMAT_UINT32: return Integer.valueOf(add(value[position], value[(position + 1)], value[(position + 2)], value[(position + 3)])); case FORMAT_SINT8: return Integer.valueOf(signed(value[position] & 0xFF, 8)); case FORMAT_SINT16: return Integer.valueOf(signed(add(value[position], value[(position + 1)]), 16)); case FORMAT_SINT32: return Integer.valueOf(signed(add(value[position], value[(position + 1)], value[(position + 2)], value[(position + 3)]), 32)); } return null; } public static Float getFloatValue(byte[] value, int format, int position) { if (value == null) return null; if (position + (format & 0xF) > value.length) return null; int i; int mantissa; int exponent; switch (format) { case FORMAT_SFLOAT: i = value[(position + 1)]; position = value[position]; mantissa = signed((position & 0xFF) + ((i & 0xFF & 0xF) << 8), 12); exponent = signed((i & 0xFF) >> 4, 4); return Float.valueOf((float) (mantissa * Math.pow(10.0D, exponent))); case FORMAT_FLOAT: exponent = value[(position + 3)]; mantissa = value[(position + 2)]; i = value[(position + 1)]; position = value[position]; return Float.valueOf((float) ((format = signed((position & 0xFF) + ((i & 0xFF) << 8) + ((mantissa & 0xFF) << 16), 24)) * Math.pow(10.0D, exponent))); } return null; } public static String getStringValue(byte[] value, int position) { if (value == null) return null; if (position > value.length) return null; byte[] arrayOfByte = new byte[value.length - position]; for (int i = 0; i != value.length - position; i++) { arrayOfByte[i] = value[(position + i)]; } return new Ssortingng(arrayOfByte); } private static int add(byte byte1, byte byte2) { return (byte1 & 0xFF) + ((byte2 & 0xFF) << 8); } private static int add(byte byte1, byte byte2, byte byte3, byte byte4) { return (byte1 & 0xFF) + ((byte2 & 0xFF) << 8) + ((byte3 & 0xFF) << 16) + ((byte4 & 0xFF) << 24); } private static int signed(int value, int length) { if ((value & 1 << length - 1) != 0) value = -1 * ((1 << length - 1) - (value & (1 << length - 1) - 1)); return value; } /** * Convert hex byte array from motorola API to byte array. * * @param hexByteArray * @return */ public static byte[] hexByteArrayToByteArray(byte[] hexByteArray) { return hexStringToByteArray(new String(hexByteArray)); } /** * Convert string from motorola API to a byte array. * * @param hexString * @return */ public static byte[] hexStringToByteArray(String hexString) { int len = hexString.length(); byte[] data = new byte[len / 2]; for (int i = 0; i < len; i += 2) { data[i / 2] = (byte) ((Character.digit(hexString.charAt(i), 16) << 4) + Character.digit(hexString.charAt(i + 1), 16)); } return data; } } 

 public int toInt(byte hb, byte lb) { return ((int)hb)<<8 + lb; }