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.sumup.codec; 21 22 import org.apache.mina.common.ByteBuffer; 23 import org.apache.mina.common.IoSession; 24 import org.apache.mina.example.sumup.message.AbstractMessage; 25 import org.apache.mina.filter.codec.ProtocolEncoderOutput; 26 import org.apache.mina.filter.codec.demux.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 (mina-dev@directory.apache.org) 33 * @version $Rev: 555855 $, $Date: 2007-07-13 12:19:00 +0900 (금, 13 7월 2007) $ 34 */ 35 public abstract class AbstractMessageEncoder implements MessageEncoder { 36 private final int type; 37 38 protected AbstractMessageEncoder(int type) { 39 this.type = type; 40 } 41 42 public void encode(IoSession session, Object message, 43 ProtocolEncoderOutput out) throws Exception { 44 AbstractMessage m = (AbstractMessage) message; 45 ByteBuffer buf = ByteBuffer.allocate(16); 46 buf.setAutoExpand(true); // Enable auto-expand for easier encoding 47 48 // Encode a header 49 buf.putShort((short) type); 50 buf.putInt(m.getSequence()); 51 52 // Encode a body 53 encodeBody(session, m, buf); 54 buf.flip(); 55 out.write(buf); 56 } 57 58 protected abstract void encodeBody(IoSession session, 59 AbstractMessage message, ByteBuffer out); 60 }