Что говорит Javadoc ?
чтение ()
Reads the next byte of data from the input stream.
The value byte is returned as an int in the range
0 to 255. <b>If no byte is available because the end
of the stream has been reached, the value -1 is
returned. This method blocks until input data
is available, the end of the stream is detected,
or an exception is thrown</b>.
A subclass must provide an implementation of this method.
чтения (байт [])
Reads some number of bytes from the input stream
and stores them into the buffer array b. The
number of bytes actually read is returned as
an integer. <b>This method blocks until input
data is available, end of file is detected,
or an exception is thrown. </b>
If b is null, a NullPointerException is thrown.
If the length of b is zero, then no bytes
are read and 0 is returned; otherwise, there is
an attempt to read at least one byte. <b>If no
byte is available because the stream is at end
of file, the value -1 is returned</b>; otherwise,
at least one byte is read and stored into b.
The first byte read is stored into element b[0],
the next one into b[1], and so on. The number
of bytes read is, at most, equal to the length
of b. Let k be the number of bytes actually read;
these bytes will be stored in elements b[0]
through b[k-1], leaving elements b[k] through
b[b.length-1] unaffected.
<b>If the first byte cannot be read for any reason
other than end of file, then an IOException
is thrown. In particular, an IOException is
thrown if the input stream has been closed.</b>
The read(b) method for class InputStream
has the same effect as:
read(b, 0, b.length)
read (byte [], int, int)
Reads up to len bytes of data from the input
stream into an array of bytes. An attempt
is made to read as many as len bytes, but
a smaller number may be read. The number of bytes
actually read is returned as an integer.
<b>This method blocks until input data is
available, end of file is detected, or an exception
is thrown.</b>
If b is null, a NullPointerException is thrown.
If off is negative, or len is negative, or off+len
is greater than the length of the array
b, then an IndexOutOfBoundsException is thrown.
If len is zero, then no bytes are read and 0 is
returned; otherwise, there is an attempt to
read at least one byte. <b>If no byte is available
because the stream is at end of file, the
value -1 is returned</b>; otherwise, at least one
byte is read and stored into b.
The first byte read is stored into element b[off],
the next one into b[off+1], and so on. The number
of bytes read is, at most, equal to len. Let k be
the number of bytes actually read; these bytes will
be stored in elements b[off] through b[off+k-1],
leaving elements b[off+k] through b[off+len-1] unaffected.
In every case, elements b[0] through b[off] and
elements b[off+len] through b[b.length-1]
are unaffected.
<b>If the first byte cannot be read for any reason other
than end of file, then an IOException is thrown. In
particular, an IOException is thrown if the input
stream has been closed.</b>
The read(b, off, len) method for class InputStream
simply calls the method read() repeatedly. If the
first such call results in an IOException, that
exception is returned from the call to the read(b, off, len)
method. If any subsequent call to read() results in a
IOException, the exception is caught and treated as
if it were end of file; the bytes read up to that
point are stored into b and the number of bytes
read before the exception occurred is returned.
Subclasses are encouraged to provide a more efficient
implementation of this method.
Собственно, InputStream не имеет тайм-аутов, поэтому он зависит от того, как драйвер сообщает о результатах. Если водитель сообщает EOF, вы просто получите -1. Если драйвер сообщает об ошибке, вы должны получить IOException.