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

Method Detail

• write

  long write(ByteBuffer[] srcs,
             int offset,
             int length)
      throws IOException

  Writes a sequence of bytes to this channel from a subsequence of the given buffers.

  An attempt is made to write up to r bytes to this channel, where r is the total number of bytes remaining in the specified subsequence of the given buffer array, that is,

   srcs[offset].remaining()
       + srcs[offset+1].remaining()
       + ... + srcs[offset+length-1].remaining()

  at the moment that this method is invoked.

  Suppose that a byte sequence of length n is written, where 0 <= n <= r. Up to the first srcs[offset].remaining() bytes of this sequence are written from buffer srcs[offset], up to the next srcs[offset+1].remaining() bytes are written from buffer srcs[offset+1], and so forth, until the entire byte sequence is written. As many bytes as possible are written from 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.

  Unless otherwise specified, a write operation will return only after writing all of the r requested bytes. Some types of channels, depending upon their state, may write only some of the bytes or possibly none at all. A socket channel in non-blocking mode, for example, cannot write any more bytes than are free in the socket's output buffer.

  This method may be invoked at any time. If another thread has already initiated a write operation upon this channel, however, then an invocation of this method will block until the first operation is complete.

  Parameters:

  srcs - The buffers from which bytes are to be retrieved

  offset - The offset within the buffer array of the first buffer from which bytes are to be retrieved; must be non-negative and no larger than srcs.length

  length - The maximum number of buffers to be accessed; must be non-negative and no larger than srcs.length - offset

  Returns:

  The number of bytes written, possibly zero

  Throws:

  IndexOutOfBoundsException - If the preconditions on the offset and length parameters do not hold

  NonWritableChannelException - If this channel was not opened for writing

  ClosedChannelException - If this channel is closed

  AsynchronousCloseException - If another thread closes this channel while the write operation is in progress

  ClosedByInterruptException - If another thread interrupts the current thread while the write operation is in progress, thereby closing the channel and setting the current thread's interrupt status

  IOException - If some other I/O error occurs

• write

  long write(ByteBuffer[] srcs)
      throws IOException

  Writes a sequence of bytes to this channel from the given buffers.

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

   c.write(srcs, 0, srcs.length);

  Parameters:

  srcs - The buffers from which bytes are to be retrieved

  Returns:

  The number of bytes written, possibly zero

  Throws:

  NonWritableChannelException - If this channel was not opened for writing

  ClosedChannelException - If this channel is closed

  AsynchronousCloseException - If another thread closes this channel while the write operation is in progress

  ClosedByInterruptException - If another thread interrupts the current thread while the write operation is in progress, thereby closing the channel and setting the current thread's interrupt status

  IOException - If some other I/O error occurs