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big endian vs little endian data

It appears that the data I/O methods for the RandomAccessFil e class
(e.g. readInt() and writeInt()) handle data in "big endian format"
(most significant byte first). If you have a file where the data was
written in "little endian format" (least significant byte first" how
is the best way to read that data in Java?

Dave Eland
da******@oru.ed u
Jul 17 '05 #1
2 21420
Dave Eland <da******@oru.e du> wrote in message news:<rh******* *************** **********@4ax. com>...
It appears that the data I/O methods for the RandomAccessFil e class
(e.g. readInt() and writeInt()) handle data in "big endian format"
(most significant byte first). If you have a file where the data was
written in "little endian format" (least significant byte first" how
is the best way to read that data in Java?

Dave Eland
da******@oru.ed u


OK, if your reading ints, pullout each int and reverse the bytes.

int i = input_stream.re adInt();
i = ((i & 0x000000ff) << 24) + ((i & 0x0000ff00) << 8) +
((i & 0x00ff0000) >>> 8) + ((i & 0xff000000) >>> 24);
Hope this helps.

AJG
Jul 17 '05 #2
Dave Eland wrote:
It appears that the data I/O methods for the RandomAccessFil e class
(e.g. readInt() and writeInt()) handle data in "big endian format"
(most significant byte first). If you have a file where the data was
written in "little endian format" (least significant byte first" how
is the best way to read that data in Java?

Dave Eland
da******@oru.ed u


Look at ByteBuffer & company. Something like this:

RandomAccessFil e file = new RandomAccessFil e(filename, "r");
byte[] recordBuffer = new byte[RECORD_LENGTH];
ByteBuffer record = ByteBuffer.wrap (recordBuffer);
record.order(By teOrder.BIG_END IAN);
FloatBuffer floatRecordBuff er = record.asFloatB uffer();
IntBuffer intRecordBuffer = record.asIntBuf fer();

Use

file.seek(offse t);
file.read(recor dBuffer);

to read the file, and

intRecordBuffer .rewind();
intRecordBuffer .get(arrayOfInt s, offset, sizeOfArray);

to get it into your arrayOfInts.

Jul 17 '05 #3

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