| /* |
| * 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.camel.example.netty; |
| |
| import java.nio.charset.Charset; |
| |
| import io.netty.buffer.ByteBuf; |
| import io.netty.buffer.Unpooled; |
| import io.netty.channel.ChannelHandlerContext; |
| import io.netty.handler.codec.DecoderException; |
| import io.netty.handler.codec.DelimiterBasedFrameDecoder; |
| |
| /** |
| * Netty decoder that assembles a complete messages from the frames received by Netty. |
| * The decoder uses delimter based on start and end byte markers, to know when all |
| * data for a complete message has been received. |
| */ |
| public class MyCodecDecoder extends DelimiterBasedFrameDecoder { |
| |
| private static final int MAX_FRAME_LENGTH = 4096; |
| |
| private static char startByte = 0x0b; // 11 decimal |
| private static char endByte1 = 0x1c; // 28 decimal |
| private static char endByte2 = 0x0d; // 13 decimal |
| |
| public MyCodecDecoder() { |
| super(MAX_FRAME_LENGTH, true, Unpooled.copiedBuffer( |
| new char[]{endByte1, endByte2}, Charset.defaultCharset())); |
| } |
| |
| @Override |
| protected Object decode(ChannelHandlerContext ctx, ByteBuf buffer) throws Exception { |
| ByteBuf buf = (ByteBuf) super.decode(ctx, buffer); |
| if (buf != null) { |
| try { |
| int pos = buf.bytesBefore((byte) startByte); |
| if (pos >= 0) { |
| ByteBuf msg = buf.readerIndex(pos + 1).slice(); |
| return asString(msg); |
| } else { |
| throw new DecoderException("Did not find start byte " + (int) startByte); |
| } |
| } finally { |
| // We need to release the buf here to avoid the memory leak |
| buf.release(); |
| } |
| } |
| // Message not complete yet - return null to be called again |
| return null; |
| } |
| |
| private String asString(ByteBuf msg) { |
| // convert the message to a String which Camel will then use |
| String text = msg.toString(Charset.defaultCharset()); |
| return text; |
| } |
| |
| } |