1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 *
19 */
20 package org.apache.mina.core.service;
21
22 import java.io.IOException;
23
24 import org.apache.mina.core.session.IdleStatus;
25 import org.apache.mina.core.session.IoSession;
26
27 /**
28 * Handles all I/O events fired by MINA.
29 *
30 * @author The Apache MINA Project (dev@mina.apache.org)
31 *
32 * @see IoHandlerAdapter
33 */
34 public interface IoHandler {
35 /**
36 * Invoked from an I/O processor thread when a new connection has been created.
37 * Because this method is supposed to be called from the same thread that
38 * handles I/O of multiple sessions, please implement this method to perform
39 * tasks that consumes minimal amount of time such as socket parameter
40 * and user-defined session attribute initialization.
41 */
42 void sessionCreated(IoSession session) throws Exception;
43
44 /**
45 * Invoked when a connection has been opened. This method is invoked after
46 * {@link #sessionCreated(IoSession)}. The biggest difference from
47 * {@link #sessionCreated(IoSession)} is that it's invoked from other thread
48 * than an I/O processor thread once thread model is configured properly.
49 */
50 void sessionOpened(IoSession session) throws Exception;
51
52 /**
53 * Invoked when a connection is closed.
54 */
55 void sessionClosed(IoSession session) throws Exception;
56
57 /**
58 * Invoked with the related {@link IdleStatus} when a connection becomes idle.
59 * This method is not invoked if the transport type is UDP; it's a known bug,
60 * and will be fixed in 2.0.
61 */
62 void sessionIdle(IoSession session, IdleStatus status) throws Exception;
63
64 /**
65 * Invoked when any exception is thrown by user {@link IoHandler}
66 * implementation or by MINA. If <code>cause</code> is an instance of
67 * {@link IOException}, MINA will close the connection automatically.
68 */
69 void exceptionCaught(IoSession session, Throwable cause) throws Exception;
70
71 /**
72 * Invoked when a message is received.
73 */
74 void messageReceived(IoSession session, Object message) throws Exception;
75
76 /**
77 * Invoked when a message written by {@link IoSession#write(Object)} is
78 * sent out.
79 */
80 void messageSent(IoSession session, Object message) throws Exception;
81 }