/*
* 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.sumup.codec;
import org.apache.mina.common.ByteBuffer;
import org.apache.mina.common.IoSession;
import org.apache.mina.example.sumup.message.AbstractMessage;
import org.apache.mina.filter.codec.ProtocolEncoderOutput;
import org.apache.mina.filter.codec.demux.MessageEncoder;
/**
* A {@link MessageEncoder} that encodes message header and forwards
* the encoding of body to a subclass.
*
* @author The Apache Directory Project (mina-dev@directory.apache.org)
* @version $Rev: 448075 $, $Date: 2006-09-20 14:26:53 +0900 (수, 20 9월 2006) $
*/
public abstract class AbstractMessageEncoder implements MessageEncoder
{
private final int type;
protected AbstractMessageEncoder( int type )
{
this.type = type;
}
public void encode( IoSession session, Object message, ProtocolEncoderOutput out ) throws Exception
{
AbstractMessage m = ( AbstractMessage ) message ;
ByteBuffer buf = ByteBuffer.allocate( 16 );
buf.setAutoExpand( true ); // Enable auto-expand for easier encoding
// Encode a header
buf.putShort( ( short ) type );
buf.putInt( m.getSequence() );
// Encode a body
encodeBody( session, m, buf );
buf.flip();
out.write( buf );
}
protected abstract void encodeBody( IoSession session, AbstractMessage message, ByteBuffer out );
}