public abstract long read (ByteBuffer[] dsts, int offset, int length) throws IOException

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+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.

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

Returns:  The number of bytes read, possibly zero, or -1 if the channel has reached end-of-stream

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