1 | /* |
2 | * @(#) $Id: AbstractMessageEncoder.java 264677 2005-08-30 02:44:35Z trustin $ |
3 | * |
4 | * Copyright 2004 The Apache Software Foundation |
5 | * |
6 | * Licensed under the Apache License, Version 2.0 (the "License"); |
7 | * you may not use this file except in compliance with the License. |
8 | * 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, software |
13 | * distributed under the License is distributed on an "AS IS" BASIS, |
14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
15 | * See the License for the specific language governing permissions and |
16 | * limitations under the License. |
17 | * |
18 | */ |
19 | package org.apache.mina.examples.sumup.codec; |
20 | |
21 | import org.apache.mina.common.ByteBuffer; |
22 | import org.apache.mina.examples.sumup.message.AbstractMessage; |
23 | import org.apache.mina.protocol.ProtocolEncoderOutput; |
24 | import org.apache.mina.protocol.ProtocolSession; |
25 | import org.apache.mina.protocol.ProtocolViolationException; |
26 | import org.apache.mina.protocol.codec.MessageEncoder; |
27 | |
28 | /** |
29 | * A {@link MessageEncoder} that encodes message header and forwards |
30 | * the encoding of body to a subclass. |
31 | * |
32 | * @author The Apache Directory Project |
33 | * @version $Rev: 264677 $, $Date: 2005-08-30 11:44:35 +0900 $ |
34 | */ |
35 | public abstract class AbstractMessageEncoder implements MessageEncoder |
36 | { |
37 | private final int type; |
38 | |
39 | protected AbstractMessageEncoder( int type ) |
40 | { |
41 | this.type = type; |
42 | } |
43 | |
44 | public void encode( ProtocolSession session, Object message, ProtocolEncoderOutput out ) throws ProtocolViolationException |
45 | { |
46 | AbstractMessage m = ( AbstractMessage ) message ; |
47 | ByteBuffer buf = ByteBuffer.allocate( 16 ); |
48 | buf.setAutoExpand( true ); // Enable auto-expand for easier encoding |
49 | |
50 | // Encode a header |
51 | buf.putShort( ( short ) type ); |
52 | buf.putInt( m.getSequence() ); |
53 | |
54 | // Encode a body |
55 | encodeBody( session, m, buf ); |
56 | buf.flip(); |
57 | out.write( buf ); |
58 | } |
59 | |
60 | protected abstract void encodeBody( ProtocolSession session, AbstractMessage message, ByteBuffer out ); |
61 | } |