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 21 package org.apache.directory.server.dns.protocol; 22 23 24 import org.apache.directory.server.dns.io.encoder.DnsMessageEncoder; 25 import org.apache.directory.server.dns.messages.DnsMessage; 26 import org.apache.mina.core.buffer.IoBuffer; 27 import org.apache.mina.core.session.IoSession; 28 import org.apache.mina.filter.codec.ProtocolEncoderAdapter; 29 import org.apache.mina.filter.codec.ProtocolEncoderOutput; 30 31 32 /** 33 * A ProtocolEncoder for use in the MINA framework that uses the 34 * DnsMessageEncoder to encode DnsMessages. 35 * 36 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 37 */ 38 public class DnsTcpEncoder extends ProtocolEncoderAdapter 39 { 40 private DnsMessageEncoder/encoder/DnsMessageEncoder.html#DnsMessageEncoder">DnsMessageEncoder encoder = new DnsMessageEncoder(); 41 42 43 public void encode( IoSession session, Object message, ProtocolEncoderOutput out ) 44 { 45 IoBuffer buf = IoBuffer.allocate( 1024 ); 46 47 // make space for short length 48 buf.putShort( ( short ) 0 ); 49 50 encoder.encode( buf, ( DnsMessage ) message ); 51 52 // mark position 53 int end = buf.position(); 54 55 // length is the data minus 2 bytes for the pre-pended length 56 short recordLength = ( short ) ( end - 2 ); 57 58 // write the length 59 buf.rewind(); 60 buf.putShort( recordLength ); 61 62 // set the position back before flipping the buffer 63 buf.position( end ); 64 buf.flip(); 65 66 out.write( buf ); 67 } 68 }