1 /*
2 * Copyright 2012 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. You may obtain a copy of the License at:
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package io.netty.handler.codec.bytes;
17
18 import io.netty.buffer.ByteBuf;
19 import io.netty.channel.ChannelHandlerContext;
20 import io.netty.channel.ChannelPipeline;
21 import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
22 import io.netty.handler.codec.LengthFieldPrepender;
23 import io.netty.handler.codec.MessageToMessageDecoder;
24
25 import java.util.List;
26
27 /**
28 * Decodes a received {@link ByteBuf} into an array of bytes.
29 * A typical setup for TCP/IP would be:
30 * <pre>
31 * {@link ChannelPipeline} pipeline = ...;
32 *
33 * // Decoders
34 * pipeline.addLast("frameDecoder",
35 * new {@link LengthFieldBasedFrameDecoder}(1048576, 0, 4, 0, 4));
36 * pipeline.addLast("bytesDecoder",
37 * new {@link ByteArrayDecoder}());
38 *
39 * // Encoder
40 * pipeline.addLast("frameEncoder", new {@link LengthFieldPrepender}(4));
41 * pipeline.addLast("bytesEncoder", new {@link ByteArrayEncoder}());
42 * </pre>
43 * and then you can use an array of bytes instead of a {@link ByteBuf}
44 * as a message:
45 * <pre>
46 * void channelRead({@link ChannelHandlerContext} ctx, byte[] bytes) {
47 * ...
48 * }
49 * </pre>
50 */
51 public class ByteArrayDecoder extends MessageToMessageDecoder<ByteBuf> {
52 @Override
53 protected void decode(ChannelHandlerContext ctx, ByteBuf msg, List<Object> out) throws Exception {
54 // copy the ByteBuf content to a byte array
55 byte[] array = new byte[msg.readableBytes()];
56 msg.getBytes(0, array);
57
58 out.add(array);
59 }
60 }