001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2021 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.checks.regexp;
021
022import java.io.File;
023
024import com.puppycrawl.tools.checkstyle.StatelessCheck;
025import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
026import com.puppycrawl.tools.checkstyle.api.FileText;
027
028/**
029 * <p>
030 * Checks that a specified pattern matches a single line in any file type.
031 * </p>
032 * <p>
033 * Rationale: This check can be used to prototype checks and to find common bad
034 * practice such as calling {@code ex.printStacktrace()},
035 * {@code System.out.println()}, {@code System.exit()}, etc.
036 * </p>
037 * <ul>
038 * <li>
039 * Property {@code format} - Specify the format of the regular expression to match.
040 * Type is {@code java.lang.String}.
041 * Default value is {@code "$."}.
042 * </li>
043 * <li>
044 * Property {@code message} - Specify the message which is used to notify about
045 * violations, if empty then default (hard-coded) message is used.
046 * Type is {@code java.lang.String}.
047 * Default value is {@code null}.
048 * </li>
049 * <li>
050 * Property {@code ignoreCase} - Control whether to ignore case when searching.
051 * Type is {@code boolean}.
052 * Default value is {@code false}.
053 * </li>
054 * <li>
055 * Property {@code minimum} - Specify the minimum number of matches required in each file.
056 * Type is {@code int}.
057 * Default value is {@code 0}.
058 * </li>
059 * <li>
060 * Property {@code maximum} - Specify the maximum number of matches required in each file.
061 * Type is {@code int}.
062 * Default value is {@code 0}.
063 * </li>
064 * <li>
065 * Property {@code fileExtensions} - Specify the file type extension of files to process.
066 * Type is {@code java.lang.String[]}.
067 * Default value is {@code ""}.
068 * </li>
069 * </ul>
070 * <p>
071 *   To configure the default check:
072 * </p>
073 * <pre>
074 * &lt;module name="RegexpSingleline" /&gt;
075 * </pre>
076 * <p>
077 *   This configuration does not match to anything,
078 *   so we do not provide any code example for it
079 *   as no violation will ever be reported.
080 * </p>
081 * <p>
082 * To configure the check to find occurrences of 'System.exit('
083 * with some <i>slack</i> of allowing only one occurrence per file:
084 * </p>
085 * <pre>
086 * &lt;module name="RegexpSingleline"&gt;
087 *   &lt;property name="format" value="System.exit\("/&gt;
088 *   &lt;!-- next line not required as 0 is the default --&gt;
089 *   &lt;property name="minimum" value="0"/&gt;
090 *   &lt;property name="maximum" value="1"/&gt;
091 * &lt;/module&gt;
092 * </pre>
093 * <p>Example:</p>
094 * <pre>
095 * class MyClass {
096 *      void myFunction() {
097 *          try {
098 *             doSomething();
099 *          } catch (Exception e) {
100 *             System.exit(1); // OK, as only there is only one occurrence.
101 *          }
102 *      }
103 *      void doSomething(){};
104 * }
105 * </pre>
106 * <pre>
107 * class MyClass {
108 *     void myFunction() {
109 *         try {
110 *             doSomething();
111 *             System.exit(0);
112 *         } catch (Exception e) {
113 *             System.exit(1); // Violation, as there are more than one occurrence.
114 *         }
115 *     }
116 *     void doSomething(){};
117 * }
118 * </pre>
119 * <p>
120 * An example of how to configure the check to make sure a copyright statement
121 * is included in the file:
122 * </p>
123 * <pre>
124 * &lt;module name="RegexpSingleline"&gt;
125 *   &lt;property name="format" value="This file is copyrighted"/&gt;
126 *   &lt;property name="minimum" value="1"/&gt;
127 *   &lt;!--  Need to specify a maximum, so 10 times is more than enough. --&gt;
128 *   &lt;property name="maximum" value="10"/&gt;
129 * &lt;/module&gt;
130 * </pre>
131 * <p>Example:</p>
132 * <pre>
133 * &#47;**
134 * * This file is copyrighted under CC. // Ok, as the file contains a copyright statement.
135 * *&#47;
136 * class MyClass {
137 *
138 * }
139 * </pre>
140 * <pre>
141 * &#47;** // violation, as the file doesn't contain a copyright statement.
142 * * MyClass as a configuration example.
143 * *&#47;
144 * class MyClass {
145 *
146 * }
147 * </pre>
148 * <p>
149 *  An example of how to configure the check to make sure sql files contains the term 'license'.
150 * </p>
151 * <pre>
152 * &lt;module name="RegexpSingleline"&gt;
153 *     &lt;property name="format" value="license"/&gt;
154 *     &lt;property name="minimum" value="1"/&gt;
155 *     &lt;property name="maximum" value="9999"/&gt;
156 *     &lt;property name="ignoreCase" value="true"/&gt;
157 *     &lt;!--  Configure a message to be shown on violation of the Check. --&gt;
158 *     &lt;property name="message"
159 *           value="File must contain at least one occurrence of 'license' term"/&gt;
160*      &lt;!--  Perform the Check only on files with java extension. --&gt;
161 *     &lt;property name="fileExtensions" value="sql"/&gt;
162 * &lt;/module&gt;
163 * </pre>
164 * <p>Example:</p>
165 * <pre>
166 * &#47;*
167 * AP 2.0 License. // Ok, Check ignores the case of the term.
168 * *&#47;
169 * CREATE DATABASE MyDB;
170 * </pre>
171 * <pre>
172 * &#47;* // violation, file doesn't contain the term.
173 * Example sql file.
174 * *&#47;
175 * CREATE DATABASE MyDB;
176 * </pre>
177 * <p>
178 * Parent is {@code com.puppycrawl.tools.checkstyle.Checker}
179 * </p>
180 * <p>
181 * Violation Message Keys:
182 * </p>
183 * <ul>
184 * <li>
185 * {@code regexp.exceeded}
186 * </li>
187 * <li>
188 * {@code regexp.minimum}
189 * </li>
190 * </ul>
191 *
192 * @since 5.0
193 */
194@StatelessCheck
195public class RegexpSinglelineCheck extends AbstractFileSetCheck {
196
197    /** Specify the format of the regular expression to match. */
198    private String format = "$.";
199    /**
200     * Specify the message which is used to notify about violations,
201     * if empty then default (hard-coded) message is used.
202     */
203    private String message;
204    /** Specify the minimum number of matches required in each file. */
205    private int minimum;
206    /** Specify the maximum number of matches required in each file. */
207    private int maximum;
208    /** Control whether to ignore case when searching. */
209    private boolean ignoreCase;
210
211    /** The detector to use. */
212    private SinglelineDetector detector;
213
214    @Override
215    public void beginProcessing(String charset) {
216        final DetectorOptions options = DetectorOptions.newBuilder()
217            .reporter(this)
218            .compileFlags(0)
219            .format(format)
220            .message(message)
221            .minimum(minimum)
222            .maximum(maximum)
223            .ignoreCase(ignoreCase)
224            .build();
225        detector = new SinglelineDetector(options);
226    }
227
228    @Override
229    protected void processFiltered(File file, FileText fileText) {
230        detector.processLines(fileText);
231    }
232
233    /**
234     * Setter to specify the format of the regular expression to match.
235     *
236     * @param format the format of the regular expression to match.
237     */
238    public void setFormat(String format) {
239        this.format = format;
240    }
241
242    /**
243     * Setter to specify the message which is used to notify about violations,
244     * if empty then default (hard-coded) message is used.
245     *
246     * @param message the message to report for a match.
247     */
248    public void setMessage(String message) {
249        this.message = message;
250    }
251
252    /**
253     * Setter to specify the minimum number of matches required in each file.
254     *
255     * @param minimum the minimum number of matches required in each file.
256     */
257    public void setMinimum(int minimum) {
258        this.minimum = minimum;
259    }
260
261    /**
262     * Setter to specify the maximum number of matches required in each file.
263     *
264     * @param maximum the maximum number of matches required in each file.
265     */
266    public void setMaximum(int maximum) {
267        this.maximum = maximum;
268    }
269
270    /**
271     * Setter to control whether to ignore case when searching.
272     *
273     * @param ignoreCase whether to ignore case when searching.
274     */
275    public void setIgnoreCase(boolean ignoreCase) {
276        this.ignoreCase = ignoreCase;
277    }
278
279}