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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    *   https://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.netty5.handler.codec.bytes;
17  
18  import io.netty5.buffer.api.Buffer;
19  import io.netty5.channel.ChannelHandlerContext;
20  import io.netty5.channel.ChannelPipeline;
21  import io.netty5.handler.codec.LengthFieldPrepender;
22  import io.netty5.handler.codec.MessageToMessageDecoder;
23  
24  /**
25   * Decodes a received {@link Buffer} into an array of bytes.
26   * A typical setup for TCP/IP would be:
27   * <pre>
28   * {@link ChannelPipeline} pipeline = ...;
29   *
30   * // Decoders
31   * pipeline.addLast("frameDecoder",
32   *                  new {@link LengthFieldBasedFrameDecoder}(1048576, 0, 4, 0, 4));
33   * pipeline.addLast("bytesDecoder",
34   *                  new {@link ByteArrayDecoder}());
35   *
36   * // Encoder
37   * pipeline.addLast("frameEncoder", new {@link LengthFieldPrepender}(4));
38   * pipeline.addLast("bytesEncoder", new {@link ByteArrayEncoder}());
39   * </pre>
40   * and then you can use an array of bytes instead of a {@link Buffer}
41   * as a message:
42   * <pre>
43   * void channelRead({@link ChannelHandlerContext} ctx, byte[] bytes) {
44   *     ...
45   * }
46   * </pre>
47   */
48  public class ByteArrayDecoder extends MessageToMessageDecoder<Buffer> {
49      @Override
50      protected void decode(ChannelHandlerContext ctx, Buffer msg) throws Exception {
51           // copy the ByteBuf content to a byte array
52          byte[] array = new byte[msg.readableBytes()];
53          msg.readBytes(array, 0, array.length);
54          ctx.fireChannelRead(array);
55      }
56  }