001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      https://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.validator.routines;
018
019import java.io.Serializable;
020
021import org.apache.commons.validator.GenericValidator;
022import org.apache.commons.validator.routines.checkdigit.CheckDigit;
023
024/**
025 * Generic <strong>Code Validation</strong> providing format, minimum/maximum
026 * length and {@link CheckDigit} validations.
027 * <p>
028 * Performs the following validations on a code:
029 * <ul>
030 *   <li>if the code is null, return null/false as appropriate</li>
031 *   <li>trim the input. If the resulting code is empty, return null/false as appropriate</li>
032 *   <li>Check the <em>format</em> of the code using a <em>regular expression.</em> (if specified)</li>
033 *   <li>Check the <em>minimum</em> and <em>maximum</em> length  (if specified) of the <em>parsed</em> code
034 *      (that is, parsed by the <em>regular expression</em>).</li>
035 *   <li>Performs {@link CheckDigit} validation on the parsed code (if specified).</li>
036 *   <li>The {@link #validate(String)} method returns the trimmed, parsed input (or null if validation failed)</li>
037 * </ul>
038 * <p>
039 * <strong>Note</strong>
040 * The {@link #isValid(String)} method will return true if the input passes validation.
041 * Since this includes trimming as well as potentially dropping parts of the input,
042 * it is possible for a String to pass validation
043 * but fail the checkdigit test if passed directly to it (the check digit routines generally don't trim input
044 * nor do they generally check the format/length).
045 * To be sure that you are passing valid input to a method use {@link #validate(String)} as follows:
046 * <pre>
047 * Object valid = validator.validate(input);
048 * if (valid != null) {
049 *    some_method(valid.toString());
050 * }
051 * </pre>
052 * <p>
053 * Configure the validator with the appropriate regular expression, minimum/maximum length
054 * and {@link CheckDigit} validator and then call one of the two validation
055 * methods provided:</p>
056 *    <ul>
057 *       <li>{@code boolean isValid(code)}</li>
058 *       <li>{@code String validate(code)}</li>
059 *    </ul>
060 * <p>
061 * Codes often include <em>format</em> characters - such as hyphens - to make them
062 * more easily human-readable. These can be removed prior to length and check digit
063 * validation by specifying them as a <em>non-capturing</em> group in the regular
064 * expression (that is, use the {@code (?:   )} notation).
065 * <br>
066 * Or just avoid using parentheses except for the parts you want to capture
067 *
068 * @since 1.4
069 */
070public final class CodeValidator implements Serializable {
071
072    private static final long serialVersionUID = 446960910870938233L;
073
074    /** The format regular expression validator. */
075    private final RegexValidator regexValidator;
076
077    /** The minimum length of the code. */
078    private final int minLength;
079
080    /** The maximum length of the code. */
081    private final int maxLength;
082
083    /** The check digit validation routine. */
084    private final CheckDigit checkdigit;
085
086    /**
087     * Constructs a code validator with a specified regular expression,
088     * validator and {@link CheckDigit} validation.
089     *
090     * @param regexValidator The format regular expression validator
091     * @param checkdigit The check digit validation routine.
092     */
093    public CodeValidator(final RegexValidator regexValidator, final CheckDigit checkdigit) {
094        this(regexValidator, -1, -1, checkdigit);
095    }
096
097    /**
098     * Constructs a code validator with a specified regular expression,
099     * validator, length and {@link CheckDigit} validation.
100     *
101     * @param regexValidator The format regular expression validator
102     * @param length The length of the code
103     *  (sets the minimum/maximum to the same value)
104     * @param checkdigit The check digit validation routine
105     */
106    public CodeValidator(final RegexValidator regexValidator, final int length, final CheckDigit checkdigit) {
107        this(regexValidator, length, length, checkdigit);
108    }
109
110    /**
111     * Constructs a code validator with a specified regular expression
112     * validator, minimum/maximum length and {@link CheckDigit} validation.
113     *
114     * @param regexValidator The format regular expression validator
115     * @param minLength The minimum length of the code
116     * @param maxLength The maximum length of the code
117     * @param checkdigit The check digit validation routine
118     */
119    public CodeValidator(final RegexValidator regexValidator, final int minLength, final int maxLength,
120            final CheckDigit checkdigit) {
121        this.regexValidator = regexValidator;
122        this.minLength = minLength;
123        this.maxLength = maxLength;
124        this.checkdigit = checkdigit;
125    }
126
127    /**
128     * Constructs a code validator with a specified regular
129     * expression and {@link CheckDigit}.
130     * The RegexValidator validator is created to be case-sensitive
131     *
132     * @param regex The format regular expression
133     * @param checkdigit The check digit validation routine
134     */
135    public CodeValidator(final String regex, final CheckDigit checkdigit) {
136        this(regex, -1, -1, checkdigit);
137    }
138
139    /**
140     * Constructs a code validator with a specified regular
141     * expression, length and {@link CheckDigit}.
142     * The RegexValidator validator is created to be case-sensitive
143     *
144     * @param regex The format regular expression.
145     * @param length The length of the code
146     *  (sets the minimum/maximum to the same)
147     * @param checkdigit The check digit validation routine
148     */
149    public CodeValidator(final String regex, final int length, final CheckDigit checkdigit) {
150        this(regex, length, length, checkdigit);
151    }
152
153    /**
154     * Constructs a code validator with a specified regular
155     * expression, minimum/maximum length and {@link CheckDigit} validation.
156     * The RegexValidator validator is created to be case-sensitive
157     *
158     * @param regex The regular expression
159     * @param minLength The minimum length of the code
160     * @param maxLength The maximum length of the code
161     * @param checkdigit The check digit validation routine
162     */
163    public CodeValidator(final String regex, final int minLength, final int maxLength,
164            final CheckDigit checkdigit) {
165        this.regexValidator = GenericValidator.isBlankOrNull(regex) ? null : new RegexValidator(regex);
166        this.minLength = minLength;
167        this.maxLength = maxLength;
168        this.checkdigit = checkdigit;
169    }
170
171    /**
172     * Gets the check digit validation routine.
173     * <p>
174     * <strong>N.B.</strong> Optional, if not set no Check Digit
175     * validation will be performed on the code.
176     *
177     * @return The check digit validation routine
178     */
179    public CheckDigit getCheckDigit() {
180        return checkdigit;
181    }
182
183    /**
184     * Gets the maximum length of the code.
185     * <p>
186     * <strong>N.B.</strong> Optional, if less than zero the
187     * maximum length will not be checked.
188     *
189     * @return The maximum length of the code or
190     * {@code -1} if the code has no maximum length
191     */
192    public int getMaxLength() {
193        return maxLength;
194    }
195
196    /**
197     * Gets the minimum length of the code.
198     * <p>
199     * <strong>N.B.</strong> Optional, if less than zero the
200     * minimum length will not be checked.
201     *
202     * @return The minimum length of the code or
203     * {@code -1} if the code has no minimum length
204     */
205    public int getMinLength() {
206        return minLength;
207    }
208
209    /**
210     * Gets the <em>regular expression</em> validator.
211     * <p>
212     * <strong>N.B.</strong> Optional, if not set no regular
213     * expression validation will be performed on the code.
214     *
215     * @return The regular expression validator
216     */
217    public RegexValidator getRegexValidator() {
218        return regexValidator;
219    }
220
221    /**
222     * Validate the code returning either {@code true}
223     * or {@code false}.
224     * <p>
225     * This calls {@link #validate(String)} and returns false
226     * if the return value is null, true otherwise.
227     * <p>
228     * Note that {@link #validate(String)} trims the input
229     * and if there is a {@link RegexValidator} it may also
230     * change the input as part of the validation.
231     *
232     * @param input The code to validate
233     * @return {@code true} if valid, otherwise
234     * {@code false}
235     */
236    public boolean isValid(final String input) {
237        return validate(input) != null;
238    }
239
240    /**
241     * Validate the code returning either the valid code or
242     * {@code null} if invalid.
243     * <p>
244     * Note that this method trims the input
245     * and if there is a {@link RegexValidator} it may also
246     * change the input as part of the validation.
247     *
248     * @param input The code to validate
249     * @return The code if valid, otherwise {@code null}
250     * if invalid
251     */
252    public Object validate(final String input) {
253        if (input == null) {
254            return null;
255        }
256        String code = input.trim();
257        if (code.isEmpty()) {
258            return null;
259        }
260        // validate/reformat using regular expression
261        if (regexValidator != null) {
262            code = regexValidator.validate(code);
263            if (code == null) {
264                return null;
265            }
266        }
267        // check the length (must be done after validate as that can change the code)
268        if (minLength >= 0 && code.length() < minLength ||
269            maxLength >= 0 && code.length() > maxLength) {
270            return null;
271        }
272        // validate the check digit
273        if (checkdigit != null && !checkdigit.isValid(code)) {
274            return null;
275        }
276        return code;
277    }
278
279}