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22 package org.apache.commons.validator;
23
24 import java.util.ArrayList;
25 import java.util.Collection;
26 import java.util.Iterator;
27
28 import org.apache.commons.validator.util.Flags;
29
30 /***
31 * <p>Perform credit card validations.</p>
32 * <p>
33 * By default, all supported card types are allowed. You can specify which
34 * cards should pass validation by configuring the validation options. For
35 * example,<br/><code>CreditCardValidator ccv = new CreditCardValidator(CreditCardValidator.AMEX + CreditCardValidator.VISA);</code>
36 * configures the validator to only pass American Express and Visa cards.
37 * If a card type is not directly supported by this class, you can implement
38 * the CreditCardType interface and pass an instance into the
39 * <code>addAllowedCardType</code> method.
40 * </p>
41 * For a similar implementation in Perl, reference Sean M. Burke's
42 * <a href="http://www.speech.cs.cmu.edu/~sburke/pub/luhn_lib.html">script</a>.
43 * More information is also available
44 * <a href="http://www.merriampark.com/anatomycc.htm">here</a>.
45 *
46 * @since Validator 1.1
47 */
48 public class CreditCardValidator {
49
50 /***
51 * Option specifying that no cards are allowed. This is useful if
52 * you want only custom card types to validate so you turn off the
53 * default cards with this option.
54 * <br/>
55 * <pre>
56 * CreditCardValidator v = new CreditCardValidator(CreditCardValidator.NONE);
57 * v.addAllowedCardType(customType);
58 * v.isValid(aCardNumber);
59 * </pre>
60 * @since Validator 1.1.2
61 */
62 public static final int NONE = 0;
63
64 /***
65 * Option specifying that American Express cards are allowed.
66 */
67 public static final int AMEX = 1 << 0;
68
69 /***
70 * Option specifying that Visa cards are allowed.
71 */
72 public static final int VISA = 1 << 1;
73
74 /***
75 * Option specifying that Mastercard cards are allowed.
76 */
77 public static final int MASTERCARD = 1 << 2;
78
79 /***
80 * Option specifying that Discover cards are allowed.
81 */
82 public static final int DISCOVER = 1 << 3;
83
84 /***
85 * The CreditCardTypes that are allowed to pass validation.
86 */
87 private Collection cardTypes = new ArrayList();
88
89 /***
90 * Create a new CreditCardValidator with default options.
91 */
92 public CreditCardValidator() {
93 this(AMEX + VISA + MASTERCARD + DISCOVER);
94 }
95
96 /***
97 * Create a new CreditCardValidator with the specified options.
98 * @param options Pass in
99 * CreditCardValidator.VISA + CreditCardValidator.AMEX to specify that
100 * those are the only valid card types.
101 */
102 public CreditCardValidator(int options) {
103 super();
104
105 Flags f = new Flags(options);
106 if (f.isOn(VISA)) {
107 this.cardTypes.add(new Visa());
108 }
109
110 if (f.isOn(AMEX)) {
111 this.cardTypes.add(new Amex());
112 }
113
114 if (f.isOn(MASTERCARD)) {
115 this.cardTypes.add(new Mastercard());
116 }
117
118 if (f.isOn(DISCOVER)) {
119 this.cardTypes.add(new Discover());
120 }
121 }
122
123 /***
124 * Checks if the field is a valid credit card number.
125 * @param card The card number to validate.
126 * @return Whether the card number is valid.
127 */
128 public boolean isValid(String card) {
129 if ((card == null) || (card.length() < 13) || (card.length() > 19)) {
130 return false;
131 }
132
133 if (!this.luhnCheck(card)) {
134 return false;
135 }
136
137 Iterator types = this.cardTypes.iterator();
138 while (types.hasNext()) {
139 CreditCardType type = (CreditCardType) types.next();
140 if (type.matches(card)) {
141 return true;
142 }
143 }
144
145 return false;
146 }
147
148 /***
149 * Add an allowed CreditCardType that participates in the card
150 * validation algorithm.
151 * @param type The type that is now allowed to pass validation.
152 * @since Validator 1.1.2
153 */
154 public void addAllowedCardType(CreditCardType type){
155 this.cardTypes.add(type);
156 }
157
158 /***
159 * Checks for a valid credit card number.
160 * @param cardNumber Credit Card Number.
161 * @return Whether the card number passes the luhnCheck.
162 */
163 protected boolean luhnCheck(String cardNumber) {
164
165 int digits = cardNumber.length();
166 int oddOrEven = digits & 1;
167 long sum = 0;
168 for (int count = 0; count < digits; count++) {
169 int digit = 0;
170 try {
171 digit = Integer.parseInt(cardNumber.charAt(count) + "");
172 } catch(NumberFormatException e) {
173 return false;
174 }
175
176 if (((count & 1) ^ oddOrEven) == 0) {
177 digit *= 2;
178 if (digit > 9) {
179 digit -= 9;
180 }
181 }
182 sum += digit;
183 }
184
185 return (sum == 0) ? false : (sum % 10 == 0);
186 }
187
188 /***
189 * CreditCardType implementations define how validation is performed
190 * for one type/brand of credit card.
191 * @since Validator 1.1.2
192 */
193 public interface CreditCardType {
194
195 /***
196 * Returns true if the card number matches this type of credit
197 * card. Note that this method is <strong>not</strong> responsible
198 * for analyzing the general form of the card number because
199 * <code>CreditCardValidator</code> performs those checks before
200 * calling this method. It is generally only required to valid the
201 * length and prefix of the number to determine if it's the correct
202 * type.
203 * @param card The card number, never null.
204 * @return true if the number matches.
205 */
206 boolean matches(String card);
207
208 }
209
210 /***
211 * Change to support Visa Carte Blue used in France
212 * has been removed - see Bug 35926
213 */
214 private class Visa implements CreditCardType {
215 private static final String PREFIX = "4";
216 public boolean matches(String card) {
217 return (
218 card.substring(0, 1).equals(PREFIX)
219 && (card.length() == 13 || card.length() == 16));
220 }
221 }
222
223 private class Amex implements CreditCardType {
224 private static final String PREFIX = "34,37,";
225 public boolean matches(String card) {
226 String prefix2 = card.substring(0, 2) + ",";
227 return ((PREFIX.indexOf(prefix2) != -1) && (card.length() == 15));
228 }
229 }
230
231 private class Discover implements CreditCardType {
232 private static final String PREFIX = "6011";
233 public boolean matches(String card) {
234 return (card.substring(0, 4).equals(PREFIX) && (card.length() == 16));
235 }
236 }
237
238 private class Mastercard implements CreditCardType {
239 private static final String PREFIX = "51,52,53,54,55,";
240 public boolean matches(String card) {
241 String prefix2 = card.substring(0, 2) + ",";
242 return ((PREFIX.indexOf(prefix2) != -1) && (card.length() == 16));
243 }
244 }
245
246 }