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Artifact providing functionality for connection related issues such as receiving or transmitting data in a unified way.
There is a newer version: 1.0.0
// /////////////////////////////////////////////////////////////////////////////
// REFCODES.ORG
// =============================================================================
// This code is copyright (c) by Siegfried Steiner, Munich, Germany and licensed
// under the following (see "http://en.wikipedia.org/wiki/Multi-licensing")
// licenses:
// =============================================================================
// GNU General Public License, v3.0 ("http://www.gnu.org/licenses/gpl-3.0.html")
// together with the GPL linking exception applied; as being applied by the GNU
// Classpath ("http://www.gnu.org/software/classpath/license.html")
// =============================================================================
// Apache License, v2.0 ("http://www.apache.org/licenses/LICENSE-2.0")
// =============================================================================
// Please contact the copyright holding author(s) of the software artifacts in
// question for licensing issues not being covered by the above listed licenses,
// also regarding commercial licensing models or regarding the compatibility
// with other open source licenses.
// /////////////////////////////////////////////////////////////////////////////

package org.refcodes.connection;

import java.io.Serializable;

import org.refcodes.component.ConnectableComponent.ConnectableAutomaton;
import org.refcodes.component.traps.OpenException;
import org.refcodes.mixin.mixins.Releaseable;

/**
 * The {@link Receiver} is used to receive datagrams in a unified way. The
 * {@link #readDatagram()} method provides the next available datagram from the
 * counterpart {@link Sender}; in case there is none available, then this method
 * halts until one is available or the {@link Receiver} is being shut down or
 * the underlying connection is closed. The {@link #hasDatagram()} method
 * returns true in case a next datagram can be fetched via the
 * {@link #readDatagram()} method from the {@link Receiver} counterpart.
 *
 * @param  The type of the datagram to be operated with.
 */
public interface Receiver extends ConnectableAutomaton, Releaseable {

	/**
	 * Reads (receives) the next datagram passed from a {@link Sender}
	 * counterpart. In case none datagram is available, then this method blocks
	 * until one is available. To prevent blocking, use the
	 * {@link #hasDatagram()} method to test beforehand whether a datagram is
	 * available (in a multi threaded usage scenario, {@link #hasDatagram()} is
	 * not a reliable indicator whether this method will block or not).
	 * 
	 * When a {@link Thread} is waiting for a datagram to be read and
	 * {@link Thread#interrupt()} is being called, then the operation is aborted
	 * and an {@link InterruptedException} is thrown.
	 * 
	 * @return The next datagram sent from the {@link Receiver} counterpart.
	 * 
	 * @throws OpenException Thrown in case opening or accessing an open line
	 *         (connection, junction, link) caused problems.
	 * 
	 * @throws InterruptedException Thrown when a {@link Thread} is waiting,
	 *         sleeping, or otherwise occupied, and the {@link Thread} is
	 *         interrupted, either before or during the activity.
	 */
	DATA readDatagram() throws OpenException, InterruptedException;

	/**
	 * Determines whether a datagram is available from a {@link Sender} and can
	 * be retrieved via the {@link #readDatagram()} method.
	 * 
	 * @return True in case there is a datagram ready to be retrieved via the
	 *         {@link #readDatagram()} method.
	 * 
	 * @throws OpenException Thrown in case opening or accessing an open line
	 *         (connection, junction, link) caused problems.
	 */
	boolean hasDatagram() throws OpenException;
}