/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *  
 *    http://www.apache.org/licenses/LICENSE-2.0
 *  
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License. 
 *  
 */
package org.apache.mina.common;

import java.io.IOException;
import java.net.SocketAddress;

/**
 * Accepts incoming connection, communicates with clients, and fires events to
 * {@link IoHandler}s.
 * <p>
 * Please refer to
 * <a href="../../../../../xref-examples/org/apache/mina/examples/echoserver/Main.html">EchoServer</a>
 * example. 
 * <p>
 * You should bind to the desired socket address to accept incoming
 * connections, and then events for incoming connections will be sent to
 * the specified default {@link IoHandler}.
 * <p>
 * Threads accept incoming connections start automatically when
 * {@link #bind(SocketAddress, IoHandler)} is invoked, and stop when all
 * addresses are unbound.
 * 
 * @author The Apache Directory Project (mina-dev@directory.apache.org)
 * @version $Rev: 555855 $, $Date: 2007-07-13 12:19:00 +0900 (Fri, 13 Jul 2007) $
 */
public interface IoAcceptor extends IoService {
    /**
     * Binds to the specified <code>address</code> and handles incoming
     * connections with the specified <code>handler</code>.
     * 
     * @throws IOException if failed to bind
     */
    void bind(SocketAddress address, IoHandler handler) throws IOException;

    /**
     * Binds to the specified <code>address</code> and handles incoming
     * connections with the specified <code>handler</code>.
     *
     * @param config the configuration
     * @throws IOException if failed to bind
     */
    void bind(SocketAddress address, IoHandler handler, IoServiceConfig config)
            throws IOException;

    /**
     * Unbinds from the specified <code>address</code> and disconnects all clients
     * connected there.
     */
    void unbind(SocketAddress address);

    /**
     * Unbinds all addresses which were bound by this acceptor.
     */
    void unbindAll();

    /**
     * (Optional) Returns an {@link IoSession} that is bound to the specified
     * <tt>localAddress</tt> and <tt>remoteAddress</tt> which reuses
     * the <tt>localAddress</tt> that is already bound by {@link IoAcceptor}
     * via {@link #bind(SocketAddress, IoHandler)}.
     * <p>
     * This operation is optional.  Please throw {@link UnsupportedOperationException}
     * if the transport type doesn't support this operation.  This operation is
     * usually implemented for connectionless transport types.
     * 
     * @throws UnsupportedOperationException if this operation is not supported
     * @throws IllegalArgumentException if the specified <tt>localAddress</tt> is
     *                                  not bound yet. (see {@link #bind(SocketAddress, IoHandler)})
     */
    IoSession newSession(SocketAddress remoteAddress, SocketAddress localAddress);
}