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From: Jeff Higgins <jeff@invalid.invalid>
Newsgroups: comp.lang.java.programmer
Subject: Re: RandomAccessFile and java.nio.*
Date: Sun, 30 Mar 2014 22:35:19 -0400
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On 03/30/2014 06:12 PM, Andreas Leitgeb wrote:
> As far as I understood the tutorials and documentation, then the java.io.*
> classes have been redesigned (already back in the Java 1.4 days) to work
> on the nio-API as its lower level.
>
>  From this, it's not surprising, that RandomAccessFile has a method to
> get access to the nio FileChannel and is mostly some convenience class
> that (among other things) allows reading single lines, and then have the
> current fileposition right after the newline of that read line.
>
> Unfortunately, however, the RandomAccessFile still has only constructors
> taking the open-mode as a String (with only "r","rw","rws","rwd" being the
> legal values).
>
> If instead I open a FileChannel using the nio API, then I can specify POSIX
> flags, like TRUNCATE or APPEND.
>
> What I'm missing is a way to wrap a RandomAccessFile over an existing
> FileChannel, such that I can use the more flexible open modes, but
> still get a convenient readLine().
>
> Btw., I'd really like a readLine() for reading lines also from Channels
> that are not FileChannel, but perhaps Pipe.SourceChannel or sockets.
>
> And just one more thing: I've seen that I can wrap streams like System.out
> in a Channel, using Channels.newChannel(System.out), but I don't know how
> I could undo this wrapping, eventually getting rid of the wrapping Channel
> without having System.out closed as a side effect. I'm a bit scared that
> merely "forgetting" the Channel might eventually cause it to be close()d
> from its finalizer.
>

?
LineNumberReader takes a Reader
Channels.newReader takes a ReadableByteChannel (FileChannel)