View Javadoc

1   /*
2    * Copyright 2009 Red Hat, Inc.
3    *
4    * Red Hat licenses this file to you under the Apache License, version 2.0
5    * (the "License"); you may not use this file except in compliance with the
6    * 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 org.jboss.netty.handler.codec.base64;
17  
18  import org.jboss.netty.buffer.ChannelBuffer;
19  import org.jboss.netty.channel.Channel;
20  import org.jboss.netty.channel.ChannelHandlerContext;
21  import org.jboss.netty.channel.ChannelPipeline;
22  import org.jboss.netty.channel.ChannelHandler.Sharable;
23  import org.jboss.netty.handler.codec.frame.DelimiterBasedFrameDecoder;
24  import org.jboss.netty.handler.codec.frame.Delimiters;
25  import org.jboss.netty.handler.codec.oneone.OneToOneEncoder;
26  
27  /**
28   * Encodes a {@link ChannelBuffer} into a Base64-encoded {@link ChannelBuffer}.
29   * A typical setup for TCP/IP would be:
30   * <pre>
31   * {@link ChannelPipeline} pipeline = ...;
32   *
33   * // Decoders
34   * pipeline.addLast("frameDecoder", new {@link DelimiterBasedFrameDecoder}(80, {@link Delimiters#nulDelimiter()}));
35   * pipeline.addLast("base64Decoder", new {@link Base64Decoder}());
36   *
37   * // Encoder
38   * pipeline.addLast("base64Encoder", new {@link Base64Encoder}());
39   * </pre>
40   *
41   * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
42   * @author <a href="http://gleamynode.net/">Trustin Lee</a>
43   * @version $Rev: 2241 $, $Date: 2010-04-16 13:12:43 +0900 (Fri, 16 Apr 2010) $
44   *
45   * @apiviz.landmark
46   * @apiviz.uses org.jboss.netty.handler.codec.base64.Base64
47   */
48  @Sharable
49  public class Base64Encoder extends OneToOneEncoder {
50  
51      private final boolean breakLines;
52      private final Base64Dialect dialect;
53  
54      public Base64Encoder() {
55          this(true);
56      }
57  
58      public Base64Encoder(boolean breakLines) {
59          this(breakLines, Base64Dialect.STANDARD);
60      }
61  
62      public Base64Encoder(boolean breakLines, Base64Dialect dialect) {
63          if (dialect == null) {
64              throw new NullPointerException("dialect");
65          }
66  
67          this.breakLines = breakLines;
68          this.dialect = dialect;
69      }
70  
71      @Override
72      protected Object encode(ChannelHandlerContext ctx, Channel channel,
73              Object msg) throws Exception {
74          if (!(msg instanceof ChannelBuffer)) {
75              return msg;
76          }
77  
78          ChannelBuffer src = (ChannelBuffer) msg;
79          return Base64.encode(
80                  src, src.readerIndex(), src.readableBytes(),
81                  breakLines, dialect);
82      }
83  }