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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 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.ChannelHandler.Sharable;
    21  import org.jboss.netty.channel.ChannelHandlerContext;
    22  import org.jboss.netty.channel.ChannelPipeline;
    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   * @apiviz.landmark
    41   * @apiviz.uses org.jboss.netty.handler.codec.base64.Base64
    42   */
    43  @Sharable
    44  public class Base64Encoder extends OneToOneEncoder {
    45
    46      private final boolean breakLines;
    47      private final Base64Dialect dialect;
    48
    49      public Base64Encoder() {
    50          this(true);
    51      }
    52
    53      public Base64Encoder(boolean breakLines) {
    54          this(breakLines, Base64Dialect.STANDARD);
    55      }
    56
    57      public Base64Encoder(boolean breakLines, Base64Dialect dialect) {
    58          if (dialect == null) {
    59              throw new NullPointerException("dialect");
    60          }
    61
    62          this.breakLines = breakLines;
    63          this.dialect = dialect;
    64      }
    65
    66      @Override
    67      protected Object encode(ChannelHandlerContext ctx, Channel channel,
    68              Object msg) throws Exception {
    69          if (!(msg instanceof ChannelBuffer)) {
    70              return msg;
    71          }
    72
    73          ChannelBuffer src = (ChannelBuffer) msg;
    74          return Base64.encode(
    75                  src, src.readerIndex(), src.readableBytes(),
    76                  breakLines, dialect);
    77      }
    78  }