Added in API level 1

ScatteringByteChannel

interface ScatteringByteChannel : ReadableByteChannel

java.nio.channels.ScatteringByteChannel

Known Direct Subclasses DatagramChannel, FileChannel, Pipe.SourceChannel, SocketChannel DatagramChannel A selectable channel for datagram-oriented sockets. FileChannel A channel for reading, writing, mapping, and manipulating a file. Pipe.SourceChannel A channel representing the readable end of a Pipe. SocketChannel A selectable channel for stream-oriented connecting sockets.

A channel that can read bytes into a sequence of buffers.

A scattering read operation reads, in a single invocation, a sequence of bytes into one or more of a given sequence of buffers. Scattering reads are often useful when implementing network protocols or file formats that, for example, group data into segments consisting of one or more fixed-length headers followed by a variable-length body. Similar gathering write operations are defined in the GatheringByteChannel interface.

Summary

Public methods
abstract Long	read(dsts: Array<ByteBuffer!>!) Reads a sequence of bytes from this channel into the given buffers.
abstract Long	read(dsts: Array<ByteBuffer!>!, offset: Int, length: Int) Reads a sequence of bytes from this channel into a subsequence of the given buffers.

Inherited functions
From class Channel Unit close() Closes this channel. After a channel is closed, any further attempt to invoke I/O operations upon it will cause a ClosedChannelException to be thrown. If this channel is already closed then invoking this method has no effect. This method may be invoked at any time. If some other thread has already invoked it, however, then another invocation will block until the first invocation is complete, after which it will return without effect. Boolean isOpen() Tells whether or not this channel is open.
From class ReadableByteChannel Int read(dst: ByteBuffer!) Reads a sequence of bytes from this channel into the given buffer. An attempt is made to read up to r bytes from the channel, where r is the number of bytes remaining in the buffer, that is, dst.remaining(), at the moment this method is invoked. Suppose that a byte sequence of length n is read, where 0 <= n <= r. This byte sequence will be transferred into the buffer so that the first byte in the sequence is at index p and the last byte is at index p + n - 1, where p is the buffer's position at the moment this method is invoked. Upon return the buffer's position will be equal to p + n; its limit will not have changed. A read operation might not fill the buffer, and in fact it might not read any bytes at all. Whether or not it does so depends upon the nature and state of the channel. A socket channel in non-blocking mode, for example, cannot read any more bytes than are immediately available from the socket's input buffer; similarly, a file channel cannot read any more bytes than remain in the file. It is guaranteed, however, that if a channel is in blocking mode and there is at least one byte remaining in the buffer then this method will block until at least one byte is read. 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.

Public methods

read

Added in API level 1

abstract fun read(dsts: Array<ByteBuffer!>!): Long

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	Array<ByteBuffer!>!: The buffers into which bytes are to be transferred

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

Exceptions
java.nio.channels.NonReadableChannelException	If this channel was not opened for reading
java.nio.channels.ClosedChannelException	If this channel is closed
java.nio.channels.AsynchronousCloseException	If another thread closes this channel while the read operation is in progress
java.nio.channels.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
java.io.IOException	If some other I/O error occurs

read

Added in API level 1

abstract fun read(
    dsts: Array<ByteBuffer!>!, 
    offset: Int, 
    length: Int
): Long

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	Array<ByteBuffer!>!: The buffers into which bytes are to be transferred
offset	Int: 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	Int: The maximum number of buffers to be accessed; must be non-negative and no larger than dsts.length - offset

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

Exceptions
java.lang.IndexOutOfBoundsException	If the preconditions on the offset and length parameters do not hold
java.nio.channels.NonReadableChannelException	If this channel was not opened for reading
java.nio.channels.ClosedChannelException	If this channel is closed
java.nio.channels.AsynchronousCloseException	If another thread closes this channel while the read operation is in progress
java.nio.channels.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
java.io.IOException	If some other I/O error occurs