In C the unsigned char data type is the only data type that has all the following three properties simultaneously it has no padding bits, that it where all storage bits contribute to the value of the data no bitwise operation starting from a value of that type, when converted back into that type, can … Read more
There seem to be some bugs with the implementation referred to by Thilo, and also copy and pasted on other sites verbatim: ByteBufferBackedInputStream.read() returns a sign extended int representation of the byte it reads, which is wrong (value should be in range [-1..255]) ByteBufferBackedInputStream.read(byte[], int, int) does not return -1 when there are no bytes … Read more
Check out the CharsetEncoder and CharsetDecoder API descriptions – You should follow a specific sequence of method calls to avoid this problem. For example, for CharsetEncoder: Reset the encoder via the reset method, unless it has not been used before; Invoke the encode method zero or more times, as long as additional input may be … Read more
One fairly common use case for the ByteBuffer is to construct some data structure piece-by-piece and then write that whole structure to disk. flip is used to flip the ByteBuffer from “reading from I/O” (putting) to “writing to I/O” (getting): after a sequence of puts is used to fill the ByteBuffer, flip will set the … Read more
Depends what you want to do. If what you want is to retrieve the bytes that are remaining (between position and limit), then what you have will work. You could also just do: ByteBuffer bb =.. byte[] b = new byte[bb.remaining()]; bb.get(b); which is equivalent as per the ByteBuffer javadocs.
You are writing to your memory stream twice, also you are not disposing the stream after use. You are also asking the image decoder to apply embedded color correction. Try this instead: using (var ms = new MemoryStream(byteArrayIn)) { return Image.FromStream(ms); }
Ron Hitches in his excellent book Java NIO seems to offer what I thought could be a good answer to your question: Operating systems perform I/O operations on memory areas. These memory areas, as far as the operating system is concerned, are contiguous sequences of bytes. It’s no surprise then that only byte buffers are … Read more
This is a good description of its uses and shortcomings. You essentially use it whenever you need to do fast low-level I/O. If you were going to implement a TCP/IP protocol or if you were writing a database (DBMS) this class would come in handy.
Try something like this: Bitmap bmp = intent.getExtras().get(“data”); ByteArrayOutputStream stream = new ByteArrayOutputStream(); bmp.compress(Bitmap.CompressFormat.PNG, 100, stream); byte[] byteArray = stream.toByteArray(); bmp.recycle();