Java integer to byte array Blackberry J2ME

Question

I've found this solution but it seems to be for Java SE. I can't find an alternative to the System.out.format() function. Also, I have changed the ByteBuffer.allocate() function to ByteBuffer.allocateDirect() is this correct?

    byte[] bytes = ByteBuffer.allocate(4).putInt(1695609641).array();

    for (byte b : bytes) {
         System.out.format("0x%x ", b);
    }

Thank you.

What [endianness](http://en.wikipedia.org/wiki/Endianness) do you want? — Mike Samuel, Mar 06 '12 at 16:21

Mike Samuel · Accepted Answer · 2012-03-11T00:01:04.757

2

If you want network byte order aka big-endian order which is used throughout Java's serialization and remoting libraries:

static byte[] intToBytesBigEndian(int i) {
  return new byte[] {
    (byte) ((i >>> 24) & 0xff),
    (byte) ((i >>> 16) & 0xff),
    (byte) ((i >>> 8) & 0xff),
    (byte) (i & 0xff),
  };
}

edited Mar 11 '12 at 00:01

answered Mar 06 '12 at 16:23

Mike Samuel

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score 0 · Answer 2 · answered Mar 06 '12 at 16:23

// 32-bit integer = 4 bytes (8 bits each)
int i = 1695609641;
byte[] bytes = new byte[4];

// big-endian, store most significant byte in byte 0
byte[3] = (byte)(i & 0xff);
i >>= 8;
byte[2] = (byte)(i & 0xff);
i >>= 8;
byte[1] = (byte)(i & 0xff);
i >>= 8;
byte[0] = (byte)(i & 0xff);

Java integer to byte array Blackberry J2ME

2 Answers2