From what I can tell, asCharBuffer behaves exactly like the other
as*Buffer methods, meaning every char in the CharBuffer is represented
by two bytes in the original ByteBuffer (big- or little-endian depending
on ByteOrder of the ByteBuffer). This means bb.asCharBuffer().get()
behaves like bb.getChar(). asCharBuffer does *not* decode using any
Charset (not the platform charset either), it just interprets the bytes
as 16-bit unsigned integers which happen to be the char type in java. I
guess this technically counts as UTF-16? It doesn't do validity checks
either, though.
If you wish to decode a ByteBuffer, you can use the CharsetDecoder API
directly. I do not believe an asCharBuffer-like method which decodes on
the fly is possible generally for all charsets, because decoding is not
necessarily possible in a random-access buffer due to dynamic-width
encoding.
- Jonas Konrad
On 02/06/2017 11:57 AM, Jay wrote:
java.nio.ByteBuffer provides a method asCharBuffer() which returns a
"view" of the ByteBuffer as a character buffer. It however does not
take any arguments. And there is no mention in the Javadocs as to how
it converts from bytes to chars.
1. There should be a method ByteBuffer.asCharBuffer(CharSet) and/or
ByteBuffer.asCharBuffer(String charSet) which allows the user to
explicitly specify the character set to be used for conversion.
2. The method ByteBuffer.asCharBuffer() should mention that this
method uses the platform default charset for bytes-to-chars
conversion.
I can provide a patch with these two changes. What do you guys think?
