How to read and write integers with a SeekableByteChannel in little endian format?

Question

I need to read and write signed and unsigned integers with a SeekableByteChannel in little endian format. This may seem silly, but I cannot find something in the JDK. Have I missed something or am I expected to roll this on my own? This would be no problem, but I don't feel like reinventing the wheel today. :-)

Do you have any code at all? I don't see anything called SeekableByteChannel in the JDK, the nearest thing I can see to that in the nio package is WritableByteChannel. — Jon, Apr 04 '12 at 14:02
Ah, I see it now. Sorry, thought I looked through 6 and 7, but actually just looked through 6 twice.. — Jon, Apr 04 '12 at 14:21

Edwin Dalorzo · Accepted Answer · 2012-04-04T14:07:00.827

2

Sounds like a work for the ByteBuffer.

Somewhat like

public static void main(String[] args) {
    byte[] payload = toArray(-1991249);
    int number = fromArray(payload);
    System.out.println(number);
}

public static  int fromArray(byte[] payload){
    ByteBuffer buffer = ByteBuffer.wrap(payload);
    buffer.order(ByteOrder.LITTLE_ENDIAN);
    return buffer.getInt();
}

public static byte[] toArray(int value){
    ByteBuffer buffer = ByteBuffer.allocate(4);
    buffer.order(ByteOrder.LITTLE_ENDIAN);
    buffer.putInt(value);
    return buffer.array();
}

edited Apr 04 '12 at 14:07

answered Apr 04 '12 at 13:58

Edwin Dalorzo

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Ahhh, that's the missing link - thanks. Of course, I need ByteOrder.LITTLE_ENDIAN. – Christian Schlichtherle Apr 04 '12 at 14:03
1

Okay, I probably need to write a decorator so that I can comfortably read and write unsigned integers. – Christian Schlichtherle Apr 04 '12 at 14:13

How to read and write integers with a SeekableByteChannel in little endian format?

1 Answers1