/*
* 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: 555855 $, $Date: 2007-07-13 12:19:00 +0900 (Fri, 13 Jul 2007) $
*/
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);
}