POSTNETLogicImpl


1   /*
2    * $Id: POSTNETLogicImpl.java,v 1.1 2003/08/18 19:31:37 jmaerki Exp $
3    * ============================================================================
4    * The Krysalis Patchy Software License, Version 1.1_01
5    * Copyright (c) 2003 Nicola Ken Barozzi.  All rights reserved.
6    *
7    * This Licence is compatible with the BSD licence as described and
8    * approved by http://www.opensource.org/, and is based on the
9    * Apache Software Licence Version 1.1.
10   *
11   * Redistribution and use in source and binary forms, with or without
12   * modification, are permitted provided that the following conditions
13   * are met:
14   *
15   * 1. Redistributions of source code must retain the above copyright
16   *    notice, this list of conditions and the following disclaimer.
17   *
18   * 2. Redistributions in binary form must reproduce the above copyright
19   *    notice, this list of conditions and the following disclaimer in
20   *    the documentation and/or other materials provided with the
21   *    distribution.
22   *
23   * 3. The end-user documentation included with the redistribution,
24   *    if any, must include the following acknowledgment:
25   *       "This product includes software developed for project
26   *        Krysalis (http://www.krysalis.org/)."
27   *    Alternately, this acknowledgment may appear in the software itself,
28   *    if and wherever such third-party acknowledgments normally appear.
29   *
30   * 4. The names "Krysalis" and "Nicola Ken Barozzi" and
31   *    "Krysalis Barcode" must not be used to endorse or promote products
32   *    derived from this software without prior written permission. For
33   *    written permission, please contact nicolaken@krysalis.org.
34   *
35   * 5. Products derived from this software may not be called "Krysalis",
36   *    "Krysalis Barcode", nor may "Krysalis" appear in their name,
37   *    without prior written permission of Nicola Ken Barozzi.
38   *
39   * 6. This software may contain voluntary contributions made by many
40   *    individuals, who decided to donate the code to this project in
41   *    respect of this licence, and was originally created by
42   *    Jeremias Maerki <jeremias@maerki.org>.
43   *
44   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
45   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
46   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
47   * DISCLAIMED.  IN NO EVENT SHALL THE KRYSALIS PROJECT OR
48   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
49   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
50   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
51   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
52   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
53   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
54   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55   * SUCH DAMAGE.
56   * ====================================================================
57   */
58  package org.krysalis.barcode.impl;
59  
60  import org.krysalis.barcode.BarGroup;
61  import org.krysalis.barcode.ChecksumMode;
62  import org.krysalis.barcode.ClassicBarcodeLogicHandler;
63  
64  /**
65   * Implements the United States Postal Service Postnet barcode.
66   * 
67   * @author Chris Dolphy
68   */
69  public class POSTNETLogicImpl {
70  
71      private static final byte[][] CHARSET = 
72                          {{2, 2, 1, 1, 1},  //0
73                           {1, 1, 1, 2, 2},  //1
74                           {1, 1, 2, 1, 2},  //2
75                           {1, 1, 2, 2, 1},  //3
76                           {1, 2, 1, 1, 2},  //4
77                           {1, 2, 1, 2, 1},  //5
78                           {1, 2, 2, 1, 1},  //6
79                           {2, 1, 1, 1, 2},  //7
80                           {2, 1, 1, 2, 1},  //8
81                           {2, 1, 2, 1, 1}}; //9
82  
83      private ChecksumMode checksumMode = ChecksumMode.CP_AUTO;
84      private static final char DASH = '-';
85  
86      /**
87       * Main constructor
88       * @param mode checksum mode
89       */
90      public POSTNETLogicImpl(ChecksumMode mode) {
91          this.checksumMode = mode;
92      }
93  
94      /**
95       * Returns the currently active checksum mode.
96       * @return the checksum mode
97       */
98      public ChecksumMode getChecksumMode() {
99          return this.checksumMode;
100     }
101 
102     /**
103      * Calculates the checksum for a message to be encoded as an 
104      * Code39 barcode.
105      * @param msg message to calculate the check digit for
106      * @return char the check digit
107      */
108     public static char calcChecksum(String   msg) {
109         int tmp = 0;
110         for (int i = 0; i < msg.length(); i++) {
111             if (isIgnoredChar(msg.charAt(i))) {
112                 continue;
113             }
114             tmp += Character.digit(msg.charAt(i), 10);
115             if (tmp > 9) {
116                 tmp -= 10;
117             }
118         }
119         return Character.forDigit((10 - tmp) % 10, 10);
120     }
121 
122 
123     /**
124      * Verifies the checksum for a message.
125      * @param msg message (check digit included)
126      * @return boolean True, if the checksum is correct
127      */
128     public static boolean validateChecksum(String   msg) {
129         char actual = msg.charAt(msg.length() - 1);
130         char expected = calcChecksum(msg.substring(0, msg.length() - 1));
131         return (actual == expected);
132     }
133 
134     private static boolean isValidChar(char ch) {
135         return Character.isDigit(ch) || isIgnoredChar(ch);
136     }
137     
138     /**
139      * Checks if a character is an ignored character (such as a '-' (dash)).
140      * @param c character to check
141      * @return True if the character is ignored
142      */
143     public static boolean isIgnoredChar(char c) {
144         return c == DASH;
145     }
146     
147     /**
148      * Removes ignored character from a valid POSTNET message.
149      * @param msg valid POSTNET message
150      * @return the message but without ignored characters
151      */
152     public static String   removeIgnoredCharacters(final String   msg) {
153         StringBuffer   sb = new StringBuffer  (msg.length());
154         for (int i = 0; i < msg.length(); i++) {
155             final char ch = msg.charAt(i);
156             if (!isValidChar(ch)) {
157                 throw new IllegalArgumentException  ("Invalid character: " + ch);
158             }
159             if (!isIgnoredChar(ch)) {
160                 sb.append(ch);
161             }
162         }
163         return sb.toString();
164     }
165 
166     private int heightAt(char ch, int index) {
167         int chidx = Character.digit(ch, 10);
168         if (chidx >= 0) {
169             int height = CHARSET[chidx][index];
170             return height;
171         } else {
172             throw new IllegalArgumentException  ("Invalid character: " + ch);
173         }
174     }
175 
176     /**
177      * Encodes a single character.
178      * @param logic the logic handler to receive generated events
179      * @param c the character to encode
180      */
181     protected void encodeChar(ClassicBarcodeLogicHandler logic, char c) {
182         if (isIgnoredChar(c)) {
183             return;  // allow dash, but don't encode
184         }
185         logic.startBarGroup(BarGroup.MSG_CHARACTER, new Character  (c).toString());
186         for (byte i = 0; i < 5; i++) {
187             int height = heightAt(c, i);
188             logic.addBar(true, height);
189             addIntercharacterGap(logic);
190         }
191         logic.endBarGroup();
192     }
193 
194     private void addIntercharacterGap(ClassicBarcodeLogicHandler logic) {
195         logic.addBar(false, -1); //-1 is special
196     }
197         
198     private void handleChecksum(StringBuffer   sb) {
199         if (getChecksumMode() == ChecksumMode.CP_ADD) {
200             sb.append(calcChecksum(sb.toString()));
201         } else if (getChecksumMode() == ChecksumMode.CP_CHECK) {
202             if (!validateChecksum(sb.toString())) {
203                 throw new IllegalArgumentException  ("Message '" 
204                     + sb.toString()
205                     + "' has a bad checksum. Expected: " 
206                     + calcChecksum(sb.toString()));
207             }
208         } else if (getChecksumMode() == ChecksumMode.CP_IGNORE) {
209             return;
210         } else if (getChecksumMode() == ChecksumMode.CP_AUTO) {
211             return; //equals ignore
212         }
213     }
214 
215     /**
216      * Generates the barcode logic
217      * @param logic the logic handler to receive generated events
218      * @param msg the message to encode
219      */
220     public void generateBarcodeLogic(ClassicBarcodeLogicHandler logic, String   msg) {
221         logic.startBarcode(msg);
222 
223         StringBuffer   sb = new StringBuffer  (msg);
224 
225         handleChecksum(sb);
226 
227         // start frame bar
228         logic.addBar(true, 2);
229         addIntercharacterGap(logic);
230 
231         // encode message
232         for (int i = 0; i < sb.length(); i++) {
233             final char ch = sb.charAt(i);
234             if (!isValidChar(ch)) {
235                 throw new IllegalArgumentException  ("Invalid character: " + ch);
236             } 
237             encodeChar(logic, ch);
238         }
239 
240         // end frame bar
241         logic.addBar(true, 2);
242 
243         logic.endBarcode();
244     }
245 
246 
247 }
248
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