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.routines.checkdigit;
18
19 /**
20 * Modulus 10 <b>SEDOL</b> (UK Securities) Check Digit calculation/validation.
21 *
22 * <p>
23 * SEDOL Numbers are 7 character alphanumeric codes used
24 * to identify UK Securities (SEDOL stands for Stock Exchange Daily Official List).
25 * </p>
26 * <p>
27 * Check digit calculation is based on <i>modulus 10</i> with digits being weighted
28 * based on their position, from left to right, as follows:
29 * </p>
30 * <pre><code>
31 * position: 1 2 3 4 5 6 7
32 * weighting: 1 3 1 7 3 9 1
33 * </code></pre>
34 * <p>
35 * See <a href="https://en.wikipedia.org/wiki/SEDOL">Wikipedia - SEDOL</a>
36 * for more details.
37 * </p>
38 *
39 * @since 1.4
40 */
41 public final class SedolCheckDigit extends ModulusCheckDigit {
42
43 private static final long serialVersionUID = -8976881621148878443L;
44
45 private static final int MAX_ALPHANUMERIC_VALUE = 35; // Character.getNumericValue('Z')
46
47 /** Singleton SEDOL check digit instance */
48 public static final CheckDigit SEDOL_CHECK_DIGIT = new SedolCheckDigit();
49
50 /** Weighting given to digits depending on their right position */
51 private static final int[] POSITION_WEIGHT = {1, 3, 1, 7, 3, 9, 1};
52
53 /**
54 * Constructs a modulus 10 Check Digit routine for ISBN-10.
55 */
56 public SedolCheckDigit() {
57 }
58
59 /**
60 * Calculate the modulus for an SEDOL code.
61 *
62 * @param code The code to calculate the modulus for.
63 * @param includesCheckDigit Whether the code includes the Check Digit or not.
64 * @return The modulus value
65 * @throws CheckDigitException if an error occurs calculating the modulus
66 * for the specified code
67 */
68 @Override
69 protected int calculateModulus(final String code, final boolean includesCheckDigit) throws CheckDigitException {
70 if (code.length() > POSITION_WEIGHT.length) {
71 throw new CheckDigitException("Invalid Code Length = " + code.length());
72 }
73 return super.calculateModulus(code, includesCheckDigit);
74 }
75
76 /**
77 * Convert a character at a specified position to an integer value.
78 *
79 * @param character The character to convert
80 * @param leftPos The position of the character in the code, counting from left to right
81 * @param rightPos The positionof the character in the code, counting from right to left
82 * @return The integer value of the character
83 * @throws CheckDigitException if character is not alphanumeric
84 */
85 @Override
86 protected int toInt(final char character, final int leftPos, final int rightPos) throws CheckDigitException {
87 final int charValue = Character.getNumericValue(character);
88 // the check digit is only allowed to reach 9
89 final int charMax = rightPos == 1 ? 9 : MAX_ALPHANUMERIC_VALUE; // CHECKSTYLE IGNORE MagicNumber
90 if (charValue < 0 || charValue > charMax) {
91 throw new CheckDigitException("Invalid Character[" + leftPos + "," + rightPos + "] = '" + charValue + "' out of range 0 to " + charMax);
92 }
93 return charValue;
94 }
95
96 /**
97 * Calculates the <i>weighted</i> value of a character in the
98 * code at a specified position.
99 *
100 * @param charValue The numeric value of the character.
101 * @param leftPos The position of the character in the code, counting from left to right
102 * @param rightPos The positionof the character in the code, counting from right to left
103 * @return The weighted value of the character.
104 */
105 @Override
106 protected int weightedValue(final int charValue, final int leftPos, final int rightPos) {
107 return charValue * POSITION_WEIGHT[leftPos - 1];
108 }
109
110 }