/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 *
 */
package org.apache.mina.example.reverser;

import org.apache.mina.core.service.IoHandler;
import org.apache.mina.core.service.IoHandlerAdapter;
import org.apache.mina.core.session.IoSession;

/**
 * {@link IoHandler} implementation of reverser server protocol.
 *
 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
 */
public class ReverseProtocolHandler extends IoHandlerAdapter {
    @Override
    public void exceptionCaught(IoSession session, Throwable cause) {
        // Close connection when unexpected exception is caught.
        session.closeNow();
    }

    @Override
    public void messageReceived(IoSession session, Object message) {
        // Reverse reveiced string
        String str = message.toString();
        StringBuilder buf = new StringBuilder(str.length());
        for (int i = str.length() - 1; i >= 0; i--) {
            buf.append(str.charAt(i));
        }

        // and write it back.
        session.write(buf.toString());
    }
}