singlesessioniohandler.java

mina是以Java实现的一个开源的网络程序框架

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 *  Licensed to the Apache Software Foundation (ASF) under one
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 *  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
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 *
 *    http://www.apache.org/licenses/LICENSE-2.0
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 *  Unless required by applicable law or agreed to in writing,
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package org.apache.mina.handler.multiton;

import java.io.IOException;

import org.apache.mina.core.service.IoHandler;
import org.apache.mina.core.session.IdleStatus;
import org.apache.mina.core.session.IoSession;

/**
 * A session handler without an {@link IoSession} parameter for simplicity.
 * <p>
 * A {@link SingleSessionIoHandler} is similar to an {@link IoHandler} with
 * the notable difference that a {@link SingleSessionIoHandler} is used only
 * by one session at a time. Thus, there is no {@link IoSession} parameter in
 * the methods of this interface.
 * </p>
 * <p>
 * Because events are passed to the session in order, it is possible to store
 * conversational state as instance variables in this object.
 * </p>
 *
 * @author The Apache MINA Project ([e-mail])
 * @version $Rev: 671827 $, $Date: 2008-06-26 10:49:48 +0200 (Thu, 26 Jun 2008) $
 */
public interface SingleSessionIoHandler {

    /**
     * Invoked when the session is created. Initialize default socket parameters
     * and user-defined attributes here.
     *
     * @throws Exception
     * @see IoHandler#sessionCreated(IoSession)
     */
    void sessionCreated() throws Exception;

    /**
     * Invoked when the connection is opened. This method is not invoked if the
     * transport type is UDP.
     *
     * @see IoHandler#sessionOpened(IoSession)
     */
    void sessionOpened() throws Exception;

    /**
     * Invoked when the connection is closed. This method is not invoked if the
     * transport type is UDP.
     *
     * @see IoHandler#sessionClosed(IoSession)
     */
    void sessionClosed() throws Exception;

    /**
     * Invoked when the connection is idle. Refer to {@link IdleStatus}. This
     * method is not invoked if the transport type is UDP.
     *
     * @param status the type of idleness
     * @see IoHandler#sessionIdle(IoSession, IdleStatus)
     */
    void sessionIdle(IdleStatus status) throws Exception;

    /**
     * Invoked when any exception is thrown by user {@link IoHandler}
     * implementation or by MINA. If <code>cause</code> is instanceof
     * {@link IOException}, MINA will close the connection automatically.
     *
     * @param cause the caught exception
     * @see IoHandler#exceptionCaught(IoSession, Throwable)
     */
    void exceptionCaught(Throwable cause) throws Exception;

    /**
     * Invoked when protocol message is received. Implement your protocol flow
     * here.
     *
     * @param message the received message
     * @see IoHandler#messageReceived(IoSession, Object)
     */
    void messageReceived(Object message) throws Exception;

    /**
     * Invoked when protocol message that user requested by
     * {@link IoSession#write(Object)} is sent out actually.
     *
     * @param message the sent message
     * @see IoHandler#messageSent(IoSession, Object)
     */
    void messageSent(Object message) throws Exception;

}