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    1   /*
    2    *  Licensed to the Apache Software Foundation (ASF) under one
    3    *  or more contributor license agreements.  See the NOTICE file
    4    *  distributed with this work for additional information
    5    *  regarding copyright ownership.  The ASF licenses this file
    6    *  to you under the Apache License, Version 2.0 (the
    7    *  "License"); you may not use this file except in compliance
    8    *  with the License.  You may obtain a copy of the License at
    9    *
    10   *    http://www.apache.org/licenses/LICENSE-2.0
    11   *
    12   *  Unless required by applicable law or agreed to in writing,
    13   *  software distributed under the License is distributed on an
    14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    15   *  KIND, either express or implied.  See the License for the
    16   *  specific language governing permissions and limitations
    17   *  under the License.
    18   *
    19   */
    20  package org.apache.mina.filter.codec.textline;
    21
    22  import java.nio.charset.Charset;
    23  import java.nio.charset.CharsetEncoder;
    24
    25  import org.apache.mina.common.ByteBuffer;
    26  import org.apache.mina.common.IoSession;
    27  import org.apache.mina.filter.codec.ProtocolEncoder;
    28  import org.apache.mina.filter.codec.ProtocolEncoderAdapter;
    29  import org.apache.mina.filter.codec.ProtocolEncoderOutput;
    30
    31  /**
    32   * A {@link ProtocolEncoder} which encodes a string into a text line
    33   * which ends with the delimiter.
    34   *
    35   * @author The Apache Directory Project (mina-dev@directory.apache.org)
    36   * @version $Rev: 555855 $, $Date: 2007-07-13 05:19:00 +0200 (Fri, 13 Jul 2007) $,
    37   */
    38  public class TextLineEncoder extends ProtocolEncoderAdapter {
    39      private static final String ENCODER = TextLineEncoder.class.getName()
    40              + ".encoder";
    41
    42      private final Charset charset;
    43
    44      private final LineDelimiter delimiter;
    45
    46      private int maxLineLength = Integer.MAX_VALUE;
    47
    48      public TextLineEncoder() {
    49          this(Charset.defaultCharset(), LineDelimiter.UNIX);
    50      }
    51
    52      public TextLineEncoder(LineDelimiter delimiter) {
    53          this(Charset.defaultCharset(), delimiter);
    54      }
    55
    56      public TextLineEncoder(Charset charset) {
    57          this(charset, LineDelimiter.UNIX);
    58      }
    59
    60      public TextLineEncoder(Charset charset, LineDelimiter delimiter) {
    61          if (charset == null) {
    62              throw new NullPointerException("charset");
    63          }
    64          if (delimiter == null) {
    65              throw new NullPointerException("delimiter");
    66          }
    67          if (LineDelimiter.AUTO.equals(delimiter)) {
    68              throw new IllegalArgumentException(
    69                      "AUTO delimiter is not allowed for encoder.");
    70          }
    71
    72          this.charset = charset;
    73          this.delimiter = delimiter;
    74      }
    75
    76      /**
    77       * Returns the allowed maximum size of the encoded line.
    78       * If the size of the encoded line exceeds this value, the encoder
    79       * will throw a {@link IllegalArgumentException}.  The default value
    80       * is {@link Integer#MAX_VALUE}.
    81       */
    82      public int getMaxLineLength() {
    83          return maxLineLength;
    84      }
    85
    86      /**
    87       * Sets the allowed maximum size of the encoded line.
    88       * If the size of the encoded line exceeds this value, the encoder
    89       * will throw a {@link IllegalArgumentException}.  The default value
    90       * is {@link Integer#MAX_VALUE}.
    91       */
    92      public void setMaxLineLength(int maxLineLength) {
    93          if (maxLineLength <= 0) {
    94              throw new IllegalArgumentException("maxLineLength: "
    95                      + maxLineLength);
    96          }
    97
    98          this.maxLineLength = maxLineLength;
    99      }
    100
    101     public void encode(IoSession session, Object message,
    102             ProtocolEncoderOutput out) throws Exception {
    103         CharsetEncoder encoder = (CharsetEncoder) session.getAttribute(ENCODER);
    104         if (encoder == null) {
    105             encoder = charset.newEncoder();
    106             session.setAttribute(ENCODER, encoder);
    107         }
    108
    109         String value = message.toString();
    110         ByteBuffer buf = ByteBuffer.allocate(value.length())
    111                 .setAutoExpand(true);
    112         buf.putString(value, encoder);
    113         if (buf.position() > maxLineLength) {
    114             throw new IllegalArgumentException("Line length: " + buf.position());
    115         }
    116         buf.putString(delimiter.getValue(), encoder);
    117         buf.flip();
    118         out.write(buf);
    119     }
    120
    121     public void dispose() throws Exception {
    122     }
    123 }