001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 * 019 */ 020package org.apache.mina.handler.demux; 021 022import org.apache.mina.core.session.IoSession; 023 024/** 025 * A handler interface that {@link DemuxingIoHandler} forwards 026 * <code>exceptionCaught</code> events to. You have to register your 027 * handler with the type of exception you want to get notified using 028 * {@link DemuxingIoHandler#addExceptionHandler(Class, ExceptionHandler)}. 029 * 030 * @author <a href="http://mina.apache.org">Apache MINA Project</a> 031 */ 032public interface ExceptionHandler<E extends Throwable> { 033 /** 034 * A {@link ExceptionHandler} that does nothing. This is useful when 035 * you want to ignore an exception of a specific type silently. 036 */ 037 ExceptionHandler<Throwable> NOOP = new ExceptionHandler<Throwable>() { 038 public void exceptionCaught(IoSession session, Throwable cause) { 039 // Do nothing 040 } 041 }; 042 043 /** 044 * A {@link ExceptionHandler} that closes the session immediately. 045 * This is useful when you want to close the session when an exception of 046 * a specific type is raised. 047 */ 048 ExceptionHandler<Throwable> CLOSE = new ExceptionHandler<Throwable>() { 049 public void exceptionCaught(IoSession session, Throwable cause) { 050 session.close(true); 051 } 052 }; 053 054 /** 055 * Invoked when the specific type of exception is caught from the 056 * specified <code>session</code>. 057 * 058 * @param session The current session 059 * @param cause the exception's cause 060 * @throws Exception If we can't process the event 061 */ 062 void exceptionCaught(IoSession session, E cause) throws Exception; 063}