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 import org.apache.mina.filter.FilterEvent;
27
28 /**
29 * Handles all I/O events fired by MINA.
30 *
31 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
32 *
33 * @see IoHandlerAdapter
34 */
35 public interface IoHandler {
36 /**
37 * Invoked from an I/O processor thread when a new connection has been created.
38 * Because this method is supposed to be called from the same thread that
39 * handles I/O of multiple sessions, please implement this method to perform
40 * tasks that consumes minimal amount of time such as socket parameter
41 * and user-defined session attribute initialization.
42 *
43 * @param session The session being created
44 * @throws Exception If we get an exception while processing the create event
45 */
46 void sessionCreated(IoSession session) throws Exception;
47
48 /**
49 * Invoked when a connection has been opened. This method is invoked after
50 * {@link #sessionCreated(IoSession)}. The biggest difference from
51 * {@link #sessionCreated(IoSession)} is that it's invoked from other thread
52 * than an I/O processor thread once thread model is configured properly.
53 *
54 * @param session The session being opened
55 * @throws Exception If we get an exception while processing the open event
56 */
57 void sessionOpened(IoSession session) throws Exception;
58
59 /**
60 * Invoked when a connection is closed.
61 *
62 * @param session The session being closed
63 * @throws Exception If we get an exception while processing the close event
64 */
65 void sessionClosed(IoSession session) throws Exception;
66
67 /**
68 * Invoked with the related {@link IdleStatus} when a connection becomes idle.
69 * This method is not invoked if the transport type is UDP; it's a known bug,
70 * and will be fixed in 2.0.
71 *
72 * @param session The idling session
73 * @param status The session's status
74 * @throws Exception If we get an exception while processing the idle event
75 */
76 void sessionIdle(IoSession session, IdleStatus status) throws Exception;
77
78 /**
79 * Invoked when any exception is thrown by user {@link IoHandler}
80 * implementation or by MINA. If <code>cause</code> is an instance of
81 * {@link IOException}, MINA will close the connection automatically.
82 *
83 * @param session The session for which we have got an exception
84 * @param cause The exception that has been caught
85 * @throws Exception If we get an exception while processing the caught exception
86 */
87 void exceptionCaught(IoSession session, Throwable cause) throws Exception;
88
89 /**
90 * Invoked when a message is received.
91 *
92 * @param session The session that is receiving a message
93 * @param message The received message
94 * @throws Exception If we get an exception while processing the received message
95 */
96 void messageReceived(IoSession session, Object message) throws Exception;
97
98 /**
99 * Invoked when a message written by {@link IoSession#write(Object)} is
100 * sent out.
101 *
102 * @param session The session that has sent a full message
103 * @param message The sent message
104 * @throws Exception If we get an exception while processing the sent message
105 */
106 void messageSent(IoSession session, Object message) throws Exception;
107
108 /**
109 * Handle the closure of an half-duplex TCP channel
110 *
111 * @param session The session which input is being closed
112 * @throws Exception If we get an exception while closing the input
113 */
114 void inputClosed(IoSession session) throws Exception;
115
116 /**
117 * Invoked when a filter event is fired. Each filter might sent a different event,
118 * this is very application specific.
119 *
120 * @param session The session for which we have an event to process
121 * @param event The event to process
122 * @throws Exception If we get an exception while processing the event
123 */
124 void event(IoSession session, FilterEvent event) throws Exception;
125 }