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1   /*
2    * db2sa: DB2 Syntax Assistant
3    * Copyright (C) Andres Gomez Casanova
4    *
5    * This file is part of db2sa.
6    *
7    * db2sa is free software: you can redistribute it and/or modify
8    * it under the terms of the GNU Lesser General Public License as published by
9    * the Free Software Foundation; either version 3 of the License, or
10   * (at your option) any later version.
11   *
12   * db2sa is distributed in the hope that it will be useful,
13   * but WITHOUT ANY WARRANTY; without even the implied warranty of
14   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   * GNU Lesser General Public License for more details.
16   *
17   * You should have received a copy of the GNU Lesser General Public License
18   * along with this library; if not, see <http://www.gnu.org/licenses/>.
19   *
20   * Contact:
21   * a n g o c a  at  y a h o o  dot  c o m
22   * Cra. 45 No 61 - 31, Bogota, Colombia.
23   *
24   * Author:   $LastChangedBy: angoca $:
25   * Date:     $LastChangedDate: 2009-06-29 23:12:30 +0200 (Mon, 29 Jun 2009) $:
26   * Revision: $LastChangedRevision: 258 $:
27   * URL:      $HeadURL: https://db2sa.svn.sourceforge.net/svnroot/db2sa/branches/db2sa_beta/source-code/src/main/java/name/angoca/db2sa/cli/system/SystemInputReader.java $:
28   */
29  package name.angoca.db2sa.cli.system;
30  
31  import java.io.IOException;
32  
33  import name.angoca.db2sa.cli.InputReader;
34  import name.angoca.db2sa.cli.OutputWriter;
35  import name.angoca.db2sa.cli.exceptions.InputReaderException;
36  import name.angoca.db2sa.cli.exceptions.OutputWriterException;
37  
38  /**
39   * Implementation of the input reader using the System.In option. This class
40   * flushes the stream before start to read.<br/>
41   * <b>Control Version</b><br />
42   * <ul>
43   * <li>0.0.1 Class creation.</li>
44   * <li>0.0.2 No override.</li>
45   * <li>0.0.3 finals.</li>
46   * <li>1.0.0 Moved to version 1.</li>
47   * </ul>
48   * 
49   * @author Andres Gomez Casanova <a
50   *         href="mailto:a n g o c a at y a h o o dot c o m">(AngocA)</a>
51   * @version 1.0.0 2009-07-19
52   */
53  public final class SystemInputReader implements InputReader {
54  
55      /**
56       * Prompt to show in the console.
57       */
58      private final transient String m_prompt;
59      /**
60       * OutputWriter to write the prompt.
61       */
62      private final transient OutputWriter m_output;
63  
64      /**
65       * Constructor that flushes the stream.
66       * 
67       * @param outputWriter
68       *            OutputWriter to write the prompt.
69       * @param prompt
70       *            Prompt to show in each line of the console.
71       * @throws InputReaderException
72       *             If there is a problem flushing the stream.
73       */
74      public SystemInputReader(final OutputWriter/* ! */outputWriter,
75              final String /* ! */prompt) throws InputReaderException {
76          try {
77              this.flush();
78          } catch (final IOException exception) {
79              throw new InputReaderException(exception);
80          }
81          this.m_output = outputWriter;
82          this.m_prompt = prompt;
83      }
84  
85      /**
86       * Method that flushes the stream. It is a good idea to call it before to
87       * start to read.
88       * 
89       * @throws IOException
90       *             If there is a problem when reading.
91       */
92      private void flush() throws IOException {
93          while ((System.in.available()) != 0) {
94              System.in.read();
95          }
96      }
97  
98      /*
99       * (non-Javadoc)
100      * 
101      * @see name.angoca.db2sa.cli.InputReader#readString()
102      */
103     public String/* ! */readString() throws InputReaderException {
104         try {
105             this.m_output.writeString(this.m_prompt);
106         } catch (OutputWriterException exception) {
107             throw new InputReaderException(exception);
108         }
109 
110         int character;
111         final StringBuffer string = new StringBuffer();
112         boolean finished = false;
113         try {
114             while (!finished) {
115                 character = System.in.read();
116 
117                 if (character < 0 || (char) character == '\n') {
118                     finished = true;
119                 } else if ((char) character != '\r') {
120                     string.append((char) character);
121                 }
122             }
123         } catch (final IOException exception) {
124             throw new InputReaderException(exception);
125         }
126         return string.toString();
127     }
128 }