long Value to byte Array of size 4

[Karthik Rajendiran]

Hello Friends,
I have long value ,which i need to store in byte array of size 4.How to do that
Can any one please give me the code?

[Henry Wong]

A "long" value is 64 bits -- which means that it needs a byte array of size 8. Unless of course, you mean an "int" value.

Anyway, here is the easiest way to do this...

  public static byte[] long2bytearray(long l) {
    byte b[] = new byte[8];
 
    ByteBuffer buf = ByteBuffer.wrap(b);
    buf.putLong(l);
    return b;
  }

BTW, if this is a homework question, it would be highly unlikely that your teacher will accept this solution. He/She is probably looking for a combination of shift/and/or operators.

Henry
[ October 27, 2006: Message edited by: Henry Wong ]

[Karthik Rajendiran]

Hello Henry
Thanks for your input. BTW it is not homework question.
We need to store one CRC value long in a byte array of size 4
Is it possible to do some base64 coding or compression technique?

[Henry Wong]

Is it possible to do some base64 coding or compression technique?

Base64 will actually expand the size -- every 5 bits will become 8 bits.

As for compression, unlikely. A CRC is a checksum. No common patterns. No large groups of ones or zeros. It is unlikely to get any compression on a CRC, much less get it down to half it's size.


BTW, I always thought CRC was much smaller than 64 bits. When I used them, more than a decade ago, they were only 16 bits. I guess they added much stronger checksums.

Henry
[ October 28, 2006: Message edited by: Henry Wong ]