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.core.filterchain; 021 022import org.apache.mina.core.session.IoSession; 023 024/** 025 * An interface that builds {@link IoFilterChain} in predefined way 026 * when {@link IoSession} is created. You can extract common filter chain 027 * modification logic to this interface. For example, to add a filter 028 * to the chain, 029 * <pre> 030 * public class MyFilterChainBuilder implements IoFilterChainBuilder { 031 * public void buildFilterChain( IoFilterChain chain ) throws Exception { 032 * chain.addLast( "myFilter", new MyFilter() ); 033 * } 034 * } 035 * </pre> 036 * 037 * @author <a href="http://mina.apache.org">Apache MINA Project</a> 038 */ 039public interface IoFilterChainBuilder { 040 /** 041 * An implementation which does nothing. 042 */ 043 IoFilterChainBuilder NOOP = new IoFilterChainBuilder() { 044 public void buildFilterChain(IoFilterChain chain) throws Exception { 045 } 046 047 @Override 048 public String toString() { 049 return "NOOP"; 050 } 051 }; 052 053 /** 054 * Modifies the specified <tt>chain</tt>. 055 * 056 * @param chain The chain to modify 057 * @throws Exception If the chain modification failed 058 */ 059 void buildFilterChain(IoFilterChain chain) throws Exception; 060}