Reads a sequence of bytes from this channel into a subsequence of the
given buffers.
An invocation of this method attempts to read up to r bytes
from this channel, where r is the total number of bytes remaining
the specified subsequence of the given buffer array, that is,
dsts[offset].remaining()
+ dsts[offset+1].remaining()
+ ... + dsts[offset+length-1].remaining()
at the moment that this method is invoked.
Suppose that a byte sequence of length n is read, where
0 <= n <= r.
Up to the first dsts[offset].remaining() bytes of this sequence
are transferred into buffer dsts[offset], up to the next
dsts[offset+1].remaining() bytes are transferred into buffer
dsts[offset+1], and so forth, until the entire byte sequence
is transferred into the given buffers. As many bytes as possible are
transferred into each buffer, hence the final position of each updated
buffer, except the last updated buffer, is guaranteed to be equal to
that buffer's limit.
This method may be invoked at any time. If another thread has
already initiated a read operation upon this channel, however, then an
invocation of this method will block until the first operation is
complete.
Returns:
The number of bytes read, possibly zero,
or
-1 if the channel has reached end-of-stream
Parameters:
-
dsts - The buffers into which bytes are to be transferred
-
offset - The offset within the buffer array of the first buffer into
which bytes are to be transferred; must be non-negative and no
larger than
dsts.length
-
length - The maximum number of buffers to be accessed; must be
non-negative and no larger than
dsts.length -
offset
Throws:
-
IndexOutOfBoundsException - If the preconditions on the
offset and
length
parameters do not hold
-
NonReadableChannelException - If this channel was not opened for reading
-
ClosedChannelException - If this channel is closed
-
AsynchronousCloseException - If another thread closes this channel
while the read operation is in progress
-
ClosedByInterruptException - If another thread interrupts the current thread
while the read operation is in progress, thereby
closing the channel and setting the current thread's
interrupt status
-
IOException - If some other I/O error occurs