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1   /*
2    * ------------------------------------------------------------------------------
3    * Hermes FTP Server
4    * Copyright (c) 2005-2007 Lars Behnke
5    * ------------------------------------------------------------------------------
6    * 
7    * This file is part of Hermes FTP Server.
8    * 
9    * Hermes FTP Server is free software; you can redistribute it and/or modify
10   * it under the terms of the GNU General Public License as published by
11   * the Free Software Foundation; either version 2 of the License, or
12   * (at your option) any later version.
13   * 
14   * Hermes FTP Server is distributed in the hope that it will be useful,
15   * but WITHOUT ANY WARRANTY; without even the implied warranty of
16   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17   * GNU General Public License for more details.
18   * 
19   * You should have received a copy of the GNU General Public License
20   * along with Hermes FTP Server; if not, write to the Free Software
21   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
22   * ------------------------------------------------------------------------------
23   */
24  
25  package net.sf.hermesftp.streams;
26  
27  import java.io.BufferedReader;
28  import java.io.ByteArrayInputStream;
29  import java.io.IOException;
30  import java.io.InputStream;
31  import java.io.InputStreamReader;
32  import java.io.UnsupportedEncodingException;
33  
34  /***
35   * Reads text data and makes the lines accessible as records. The records are returned as byte
36   * arrays. Internally, the a Reader is used to perform the translation from characters to bytes.
37   * 
38   * @author Lars Behnke
39   */
40  public class TextInputStream extends InputStream implements RecordReadSupport {
41  
42      private static final int     BUFFER_SIZE = 2048;
43  
44      private BufferedReader       reader;
45  
46      private String               outputEncoding;
47  
48      private ByteArrayInputStream byteBuffer;
49  
50      /***
51       * Constructor.
52       * 
53       * @param is The input stream.
54       * @param inputEncoding The encoding.
55       * @throws UnsupportedEncodingException Thrown if encoding is unknown.
56       */
57      public TextInputStream(InputStream is, String inputEncoding) throws UnsupportedEncodingException {
58          this(is, inputEncoding, null);
59      }
60  
61      /***
62       * Constructor.
63       * 
64       * @param is The input stream.
65       * @param inputEncoding The encoding of the inbound text data.
66       * @param outputEncoding The encoding of the outbound text data.
67       * @throws UnsupportedEncodingException Thrown if encoding is unknown.
68       */
69      public TextInputStream(InputStream is, String inputEncoding, String outputEncoding)
70              throws UnsupportedEncodingException {
71          super();
72          this.reader = new BufferedReader(new InputStreamReader(is, inputEncoding));
73          this.outputEncoding = outputEncoding;
74      }
75  
76      /***
77       * {@inheritDoc}
78       */
79      public int read() throws IOException {
80          int result;
81          if (byteBuffer == null) {
82              result = -1;
83          } else {
84              result = byteBuffer.read();
85          }
86          if (result == -1) {
87              char[] chars = new char[BUFFER_SIZE];
88              int charCount = reader.read(chars);
89              if (charCount == -1) {
90                  return -1;
91              }
92              String s = new String(chars, 0, charCount);
93              if (outputEncoding == null) {
94                  byteBuffer = new ByteArrayInputStream(s.getBytes());
95              } else {
96                  byteBuffer = new ByteArrayInputStream(s.getBytes(outputEncoding));
97              }
98              result = read();
99          }
100         return result;
101     }
102 
103     /***
104      * {@inheritDoc}
105      */
106     public byte[] readRecord() throws IOException {
107         byte[] result;
108         String line = reader.readLine();
109         if (line == null) {
110             result = null;
111         } else {
112             if (outputEncoding == null) {
113                 result = line.getBytes();
114             } else {
115                 result = line.getBytes(outputEncoding);
116             }
117         }
118         return result;
119     }
120 
121     /***
122      * {@inheritDoc}
123      */
124     public void close() throws IOException {
125         super.close();
126         reader.close();
127     }
128 }