io - subStream or subReader class?
in [Java Programming]
|
Prev: When String.hashCode() returns 0 (Was: what the benefit is byusing annotation, like "@Immutable" ?)
Next: Why do I get a null URL here?
From: bugbear on 28 Jul 2010 04:13 Tom Anderson wrote: > On Tue, 27 Jul 2010, bugbear wrote: > >> I've looked in the standard libraries, and Apache. >> >> I want a Reader (or Stream) that provides a view onto PART of an >> existing Reader (or Stream) defined by an offset and a size. >> >> Such an implementation would be very useful to me, e.g. for decoding >> some JPEG data (using a standard JPEG stream decoder) where the JPEG >> is actually held as a sub-set of some other file (e.g. the thumbnail >> for a giant TIFF image). >> >> Does anyone know of such a class/library? > > If i've understood you correctly, then i think this may be of use to you: > > http://commons.apache.org/fileupload/apidocs/org/apache/commons/fileupload/util/LimitedInputStream.html > > > This is a moderately common thing to need, and since it's not in the > standard library, there are dozens of other implementations of it > around, mostly with the same name! > > It's also not hard to write if you don't want to drag in another > library. You just write a FilterInputStream with a count of bytes > remaining, and implement read() and read(byte[], int, int) to check the > count and behave accordingly. And override the mark/reset methods to > respect the count, or do nothing. But I also want an offset, which makes things harder. I know how to code it - back in my career I've coded it in both C and C++. But (like any Good Boy) I was trying to avoid re-inventing the wheel. BugBear
From: Lew on 28 Jul 2010 09:02
bugbear wrote: > But I also want an offset, which makes things harder. > > I know how to code it - back in my career I've coded it in both > C and C++. > > But (like any Good Boy) I was trying to avoid re-inventing the wheel. Good thing there's <http://java.sun.com/javase/6/docs/api/java/io/RandomAccessFile.html> thrn. -- Lew |