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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.geronimo.mail.util;
21  
22  import java.io.ByteArrayOutputStream;
23  import java.io.IOException;
24  import java.io.OutputStream;
25  
26  /**
27   * Encoder for RFC1891 xtext.
28   *
29   * xtext strings are defined as
30   *
31   *    xtext = *( xchar / hexchar )
32   *
33   * where
34   *
35   *    xchar is any ASCII character in the range 33-126, EXCEPT
36   *    the characters "+" and "=".
37   *
38   *    hexchar is an ASCII "+" followed by two upper case
39   *    hexadecimal digits.
40   */
41  public class XText
42  {
43      private static final Encoder encoder = new XTextEncoder();
44  
45      /**
46       * encode the input data producing an xtext  encoded byte array.
47       *
48       * @return a byte array containing the xtext encoded data.
49       */
50      public static byte[] encode(
51          byte[]    data)
52      {
53          return encode(data, 0, data.length);
54      }
55  
56      /**
57       * encode the input data producing an xtext encoded byte array.
58       *
59       * @return a byte array containing the xtext encoded data.
60       */
61      public static byte[] encode(
62          byte[]    data,
63          int       off,
64          int       length)
65      {
66          ByteArrayOutputStream    bOut = new ByteArrayOutputStream();
67  
68          try
69          {
70              encoder.encode(data, off, length, bOut);
71          }
72          catch (IOException e)
73          {
74              throw new RuntimeException("exception encoding xtext string: " + e);
75          }
76  
77          return bOut.toByteArray();
78      }
79  
80      /**
81       * xtext encode the byte data writing it to the given output stream.
82       *
83       * @return the number of bytes produced.
84       */
85      public static int encode(
86          byte[]         data,
87          OutputStream   out)
88          throws IOException
89      {
90          return encoder.encode(data, 0, data.length, out);
91      }
92  
93      /**
94       * extext encode the byte data writing it to the given output stream.
95       *
96       * @return the number of bytes produced.
97       */
98      public static int encode(
99          byte[]         data,
100         int            off,
101         int            length,
102         OutputStream   out)
103         throws IOException
104     {
105         return encoder.encode(data, 0, data.length, out);
106     }
107 
108     /**
109      * decode the xtext encoded input data. It is assumed the input data is valid.
110      *
111      * @return a byte array representing the decoded data.
112      */
113     public static byte[] decode(
114         byte[]    data)
115     {
116         ByteArrayOutputStream    bOut = new ByteArrayOutputStream();
117 
118         try
119         {
120             encoder.decode(data, 0, data.length, bOut);
121         }
122         catch (IOException e)
123         {
124             throw new RuntimeException("exception decoding xtext string: " + e);
125         }
126 
127         return bOut.toByteArray();
128     }
129 
130     /**
131      * decode the xtext encoded String data - whitespace will be ignored.
132      *
133      * @return a byte array representing the decoded data.
134      */
135     public static byte[] decode(
136         String    data)
137     {
138         ByteArrayOutputStream    bOut = new ByteArrayOutputStream();
139 
140         try
141         {
142             encoder.decode(data, bOut);
143         }
144         catch (IOException e)
145         {
146             throw new RuntimeException("exception decoding xtext string: " + e);
147         }
148 
149         return bOut.toByteArray();
150     }
151 
152     /**
153      * decode the xtext encoded String data writing it to the given output stream,
154      * whitespace characters will be ignored.
155      *
156      * @return the number of bytes produced.
157      */
158     public static int decode(
159         String          data,
160         OutputStream    out)
161         throws IOException
162     {
163         return encoder.decode(data, out);
164     }
165 }
166