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.filterchain;
21
22 import org.apache.mina.core.session.IoSession;
23
24 /**
25 * An interface that builds {@link IoFilterChain} in predefined way
26 * when {@link IoSession} is created. You can extract common filter chain
27 * modification logic to this interface. For example, to add a filter
28 * to the chain,
29 * <pre>
30 * public class MyFilterChainBuilder implements IoFilterChainBuilder {
31 * public void buildFilterChain( IoFilterChain chain ) throws Exception {
32 * chain.addLast( "myFilter", new MyFilter() );
33 * }
34 * }
35 * </pre>
36 *
37 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
38 */
39 public interface IoFilterChainBuilder {
40 /**
41 * An implementation which does nothing.
42 */
43 IoFilterChainBuilderlterChainBuilder.html#IoFilterChainBuilder">IoFilterChainBuilder NOOP = new IoFilterChainBuilder() {
44 /**
45 * {@inheritDoc}
46 */
47 @Override
48 public void buildFilterChain(IoFilterChain chain) throws Exception {
49 }
50
51 /**
52 * {@inheritDoc}
53 */
54 @Override
55 public String toString() {
56 return "NOOP";
57 }
58 };
59
60 /**
61 * Modifies the specified <tt>chain</tt>.
62 *
63 * @param chain The chain to modify
64 * @throws Exception If the chain modification failed
65 */
66 void buildFilterChain(IoFilterChain chain) throws Exception;
67 }