/* * Copyright (c) 2000, 2003, Oracle and/or its affiliates. All rights reserved. * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. * * * * * * * * * * * * * * * * * * * * */ package java.nio.channels; import java.io.IOException; import java.io.Closeable; /** * A nexus for I/O operations. * * <p> A channel represents an open connection to an entity such as a hardware * device, a file, a network socket, or a program component that is capable of * performing one or more distinct I/O operations, for example reading or * writing. * * <p> A channel is either open or closed. A channel is open upon creation, * and once closed it remains closed. Once a channel is closed, any attempt to * invoke an I/O operation upon it will cause a {@link ClosedChannelException} * to be thrown. Whether or not a channel is open may be tested by invoking * its {@link #isOpen isOpen} method. * * <p> Channels are, in general, intended to be safe for multithreaded access * as described in the specifications of the interfaces and classes that extend * and implement this interface. * * * @author Mark Reinhold * @author JSR-51 Expert Group * @since 1.4 */ public interface Channel extends Closeable { /** * Tells whether or not this channel is open. </p> * * @return <tt>true</tt> if, and only if, this channel is open */ public boolean isOpen(); /** * Closes this channel. * * <p> After a channel is closed, any further attempt to invoke I/O * operations upon it will cause a {@link ClosedChannelException} to be * thrown. * * <p> If this channel is already closed then invoking this method has no * effect. * * <p> 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. </p> * * @throws IOException If an I/O error occurs */ public void close() throws IOException; }