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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.validator;
18  
19  import java.util.ArrayList;
20  import java.util.Collection;
21  import java.util.Iterator;
22  
23  import org.apache.commons.validator.util.Flags;
24  
25  /***
26   * <p>Perform credit card validations.</p>
27   * <p>
28   * By default, all supported card types are allowed.  You can specify which 
29   * cards should pass validation by configuring the validation options.  For 
30   * example,<br/><code>CreditCardValidator ccv = new CreditCardValidator(CreditCardValidator.AMEX + CreditCardValidator.VISA);</code>
31   * configures the validator to only pass American Express and Visa cards.
32   * If a card type is not directly supported by this class, you can implement
33   * the CreditCardType interface and pass an instance into the 
34   * <code>addAllowedCardType</code> method.
35   * </p>
36   * For a similar implementation in Perl, reference Sean M. Burke's
37   * <a href="http://www.speech.cs.cmu.edu/~sburke/pub/luhn_lib.html">script</a>.
38   * More information is also available
39   * <a href="http://www.merriampark.com/anatomycc.htm">here</a>.
40   *
41   * @version $Revision: 478334 $ $Date: 2006-11-22 21:31:54 +0000 (Wed, 22 Nov 2006) $
42   * @since Validator 1.1
43   */
44  public class CreditCardValidator {
45  
46      /***
47       * Option specifying that no cards are allowed.  This is useful if
48       * you want only custom card types to validate so you turn off the
49       * default cards with this option.
50       * <br/>
51       * <pre>
52       * CreditCardValidator v = new CreditCardValidator(CreditCardValidator.NONE);
53       * v.addAllowedCardType(customType);
54       * v.isValid(aCardNumber);
55       * </pre>
56       * @since Validator 1.1.2
57       */
58      public static final int NONE = 0;
59  
60      /***
61       * Option specifying that American Express cards are allowed.
62       */
63      public static final int AMEX = 1 << 0;
64  
65      /***
66       * Option specifying that Visa cards are allowed.
67       */
68      public static final int VISA = 1 << 1;
69  
70      /***
71       * Option specifying that Mastercard cards are allowed.
72       */
73      public static final int MASTERCARD = 1 << 2;
74  
75      /***
76       * Option specifying that Discover cards are allowed.
77       */
78      public static final int DISCOVER = 1 << 3;
79      
80      /***
81       * The CreditCardTypes that are allowed to pass validation.
82       */
83      private Collection cardTypes = new ArrayList();
84  
85      /***
86       * Create a new CreditCardValidator with default options.
87       */
88      public CreditCardValidator() {
89          this(AMEX + VISA + MASTERCARD + DISCOVER);
90      }
91  
92      /***
93       * Create a new CreditCardValidator with the specified options.
94       * @param options Pass in
95       * CreditCardValidator.VISA + CreditCardValidator.AMEX to specify that 
96       * those are the only valid card types.
97       */
98      public CreditCardValidator(int options) {
99          super();
100 
101         Flags f = new Flags(options);
102         if (f.isOn(VISA)) {
103             this.cardTypes.add(new Visa());
104         }
105 
106         if (f.isOn(AMEX)) {
107             this.cardTypes.add(new Amex());
108         }
109 
110         if (f.isOn(MASTERCARD)) {
111             this.cardTypes.add(new Mastercard());
112         }
113 
114         if (f.isOn(DISCOVER)) {
115             this.cardTypes.add(new Discover());
116         }
117     }
118 
119     /***
120      * Checks if the field is a valid credit card number.
121      * @param card The card number to validate.
122      * @return Whether the card number is valid.
123      */
124     public boolean isValid(String card) {
125         if ((card == null) || (card.length() < 13) || (card.length() > 19)) {
126             return false;
127         }
128 
129         if (!this.luhnCheck(card)) {
130             return false;
131         }
132         
133         Iterator types = this.cardTypes.iterator();
134         while (types.hasNext()) {
135             CreditCardType type = (CreditCardType) types.next();
136             if (type.matches(card)) {
137                 return true;
138             }
139         }
140 
141         return false;
142     }
143     
144     /***
145      * Add an allowed CreditCardType that participates in the card 
146      * validation algorithm.
147      * @param type The type that is now allowed to pass validation.
148      * @since Validator 1.1.2
149      */
150     public void addAllowedCardType(CreditCardType type){
151         this.cardTypes.add(type);
152     }
153 
154     /***
155      * Checks for a valid credit card number.
156      * @param cardNumber Credit Card Number.
157      * @return Whether the card number passes the luhnCheck.
158      */
159     protected boolean luhnCheck(String cardNumber) {
160         // number must be validated as 0..9 numeric first!!
161         int digits = cardNumber.length();
162         int oddOrEven = digits & 1;
163         long sum = 0;
164         for (int count = 0; count < digits; count++) {
165             int digit = 0;
166             try {
167                 digit = Integer.parseInt(cardNumber.charAt(count) + "");
168             } catch(NumberFormatException e) {
169                 return false;
170             }
171 
172             if (((count & 1) ^ oddOrEven) == 0) { // not
173                 digit *= 2;
174                 if (digit > 9) {
175                     digit -= 9;
176                 }
177             }
178             sum += digit;
179         }
180 
181         return (sum == 0) ? false : (sum % 10 == 0);
182     }
183     
184     /***
185      * CreditCardType implementations define how validation is performed
186      * for one type/brand of credit card.
187      * @since Validator 1.1.2
188      */
189     public interface CreditCardType {
190         
191         /***
192          * Returns true if the card number matches this type of credit
193          * card.  Note that this method is <strong>not</strong> responsible
194          * for analyzing the general form of the card number because 
195          * <code>CreditCardValidator</code> performs those checks before 
196          * calling this method.  It is generally only required to valid the
197          * length and prefix of the number to determine if it's the correct 
198          * type. 
199          * @param card The card number, never null.
200          * @return true if the number matches.
201          */
202         boolean matches(String card);
203         
204     }
205     
206     /***
207      *  Change to support Visa Carte Blue used in France
208      *  has been removed - see Bug 35926
209      */
210     private class Visa implements CreditCardType {
211         private static final String PREFIX = "4";
212         public boolean matches(String card) {
213             return (
214                 card.substring(0, 1).equals(PREFIX)
215                     && (card.length() == 13 || card.length() == 16));
216         }
217     }
218             
219     private class Amex implements CreditCardType {
220         private static final String PREFIX = "34,37,";
221         public boolean matches(String card) {
222             String prefix2 = card.substring(0, 2) + ",";
223             return ((PREFIX.indexOf(prefix2) != -1) && (card.length() == 15));
224         }
225     }
226     
227     private class Discover implements CreditCardType {
228         private static final String PREFIX = "6011";
229         public boolean matches(String card) {
230             return (card.substring(0, 4).equals(PREFIX) && (card.length() == 16));
231         }
232     }
233     
234     private class Mastercard implements CreditCardType {
235         private static final String PREFIX = "51,52,53,54,55,";
236         public boolean matches(String card) {
237             String prefix2 = card.substring(0, 2) + ",";
238             return ((PREFIX.indexOf(prefix2) != -1) && (card.length() == 16));
239         }
240     }
241 
242 }