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.example.reverser;
21
22 import org.apache.mina.core.service.IoHandler;
23 import org.apache.mina.core.service.IoHandlerAdapter;
24 import org.apache.mina.core.session.IoSession;
25
26 /**
27 * {@link IoHandler} implementation of reverser server protocol.
28 *
29 * @author The Apache MINA Project (dev@mina.apache.org)
30 */
31 public class ReverseProtocolHandler extends IoHandlerAdapter {
32 @Override
33 public void exceptionCaught(IoSession session, Throwable cause) {
34 // Close connection when unexpected exception is caught.
35 session.close(true);
36 }
37
38 @Override
39 public void messageReceived(IoSession session, Object message) {
40 // Reverse reveiced string
41 String str = message.toString();
42 StringBuilder buf = new StringBuilder(str.length());
43 for (int i = str.length() - 1; i >= 0; i--) {
44 buf.append(str.charAt(i));
45 }
46
47 // and write it back.
48 session.write(buf.toString());
49 }
50 }