Re: What replaces StringBufferInputStream

From:

"Mike Schilling" <mscottschilling@hotmail.com>

Newsgroups:

comp.lang.java.programmer

Date:

Fri, 01 Sep 2006 06:03:38 GMT

Message-ID:

<_2QJg.7226$q63.3263@newssvr13.news.prodigy.com>

"Dale King" <DaleWKing@gmail.com> wrote in message
news:fuydnQLtL-VEJWrZnZ2dnUVZ_oOdnZ2d@insightbb.com...

This assumption also simplifies the whole character encoder/decoder
system. Consider the fact that one character can map to multiple bytes,
but the reverse is not true. One byte doesn't map to multiple characters
in any known encoding. If I am reading a byte from a "ReaderInputStream"
and one character from the String can map to multiple bytes you end up
having to have some form of buffer in between because the byte you read
may only be one of several for that first character. You would also end up
buffering in the reverse direction for a "WriterOutputStream" class
because the byte you write may not be enough to write the character. But
in the directionality supported by Java there is no need for such a
buffer. The idea of converting from characters to bytes is not as
straightforward as it seems on the surface.

In UTF-8, a group of 4 bytes can map to two characters (when the code point
is > FFFF, and is represented in Java by a pair of 16-bit characters.) At
any rate, decoders don't decode a character at a time, as you'll note if you
check the Javadoc for CharacterDecoder; they decode an array or stream of
bytes into the appropriate characters, and there's always (at least
potentially) a buffer involved.