Ch 11, P436: reading randomly

object_disoriented · July 5th, 2012, 10:59 AM

In the code section, there are these lines:

Code:

final int PRIMESREQUIRED = 10;
final int LONG_BYTES = 8;                           // Number of bytes for type long
ByteBuffer buf = ByteBuffer.allocate(LONG_BYTES*PRIMESREQUIRED);

indicating a buffer size for buf of 80. In the text on page 437 it says "Because buf has a capacity of 8 bytes, only one prime is read each time."

So I recompiled it with

Code:

ByteBuffer buf = ByteBuffer.allocate(LONG_BYTES);

and it seems to work fine. Am I just getting lucky or am I right that there is a minor inconsistency in the definition of buf?

p0stalDud3 · February 24th, 2013, 03:56 PM

Did you ever figure this out? I have the same thing.

object_disoriented · February 25th, 2013, 09:44 AM

I concluded that it was an error in the code. When you randomly read a prime from the file, the buffer as in the example will have the number you want plus the next seven numbers from the file which are not required. A buffer of 8 bytes seems to me to be sufficient. I left it at

Code:

ByteBuffer buf = ByteBuffer.allocate(LONG_BYTES);