Java compact1, compact2, compact3 java.nio.channels Interface ScatteringByteChannel（JDK8）

Method Detail

• read

  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].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.

  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

  Returns:

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

  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

• read

  long read(ByteBuffer[] dsts)
     throws IOException

  Reads a sequence of bytes from this channel into the given buffers.

  An invocation of this method of the form c.read(dsts) behaves in exactly the same manner as the invocation

   c.read(dsts, 0, dsts.length);

  Parameters:

  dsts - The buffers into which bytes are to be transferred

  Returns:

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

  Throws:

  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