Only one write operation upon a writable channel may be in progress at * any given time. If one thread initiates a write operation upon a channel * then any other thread that attempts to initiate another write operation will * block until the first operation is complete. Whether or not other kinds of * I/O operations may proceed concurrently with a write operation depends upon * the type of the channel.
* * * @author Mark Reinhold * @author JSR-51 Expert Group * @version 1.15, 03/12/19 * @since 1.4 */ public interface WritableByteChannel extends Channel { /** * Writes a sequence of bytes to this channel from the given buffer. * *An attempt is made to write up to r bytes to 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 written, where * 0 <= n <= r. * This byte sequence will be transferred from the buffer starting at index * p, where p is the buffer's position at the moment this * method is invoked; the index of the last byte written will be * p + n - 1. * Upon return the buffer's position will be equal to * p + n; its limit will not have changed. * *
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.
* * @param src * The buffer from which bytes are to be retrieved * * @return The number of bytes written, possibly zero * * @throws NonWritableChannelException * If this channel was not opened for writing * * @throws ClosedChannelException * If this channel is closed * * @throws AsynchronousCloseException * If another thread closes this channel * while the write operation is in progress * * @throws 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 * * @throws IOException * If some other I/O error occurs */ public int write(ByteBuffer src) throws IOException; }