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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    *   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.buffer.Unpooled;
20  import io.netty.channel.ChannelHandler.Sharable;
21  import io.netty.channel.ChannelHandlerContext;
22  import io.netty.channel.ChannelPipeline;
23  import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
24  import io.netty.handler.codec.LengthFieldPrepender;
25  import io.netty.handler.codec.MessageToMessageEncoder;
26  
27  import java.util.List;
28  
29  /**
30   * Encodes the requested array of bytes into a {@link ByteBuf}.
31   * A typical setup for TCP/IP would be:
32   * <pre>
33   * {@link ChannelPipeline} pipeline = ...;
34   *
35   * // Decoders
36   * pipeline.addLast("frameDecoder",
37   *                  new {@link LengthFieldBasedFrameDecoder}(1048576, 0, 4, 0, 4));
38   * pipeline.addLast("bytesDecoder",
39   *                  new {@link ByteArrayDecoder}());
40   *
41   * // Encoder
42   * pipeline.addLast("frameEncoder", new {@link LengthFieldPrepender}(4));
43   * pipeline.addLast("bytesEncoder", new {@link ByteArrayEncoder}());
44   * </pre>
45   * and then you can use an array of bytes instead of a {@link ByteBuf}
46   * as a message:
47   * <pre>
48   * void channelRead({@link ChannelHandlerContext} ctx, byte[] bytes) {
49   *     ...
50   * }
51   * </pre>
52   */
53  @Sharable
54  public class ByteArrayEncoder extends MessageToMessageEncoder<byte[]> {
55      @Override
56      protected void encode(ChannelHandlerContext ctx, byte[] msg, List<Object> out) throws Exception {
57          out.add(Unpooled.wrappedBuffer(msg));
58      }
59  }