Source code

001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2025 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;
021
022import java.io.File;
023import java.io.IOException;
024import java.io.InputStream;
025import java.io.Serial;
026import java.nio.file.Files;
027import java.util.ArrayList;
028import java.util.Collections;
029import java.util.Enumeration;
030import java.util.Iterator;
031import java.util.List;
032import java.util.Properties;
033import java.util.regex.Matcher;
034import java.util.regex.Pattern;
035
036import com.puppycrawl.tools.checkstyle.StatelessCheck;
037import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
038import com.puppycrawl.tools.checkstyle.api.FileText;
039
040/**
041 * <div>
042 * Detects if keys in properties files are in correct order.
043 * </div>
044 *
045 * <p>
046 *   Rationale: Sorted properties make it easy for people to find required properties by name
047 *   in file. This makes it easier to merge. While there are no problems at runtime.
048 *   This check is valuable only on files with string resources where order of lines
049 *   does not matter at all, but this can be improved.
050 *   E.g.: checkstyle/src/main/resources/com/puppycrawl/tools/checkstyle/messages.properties
051 *   You may suppress warnings of this check for files that have a logical structure like
052 *   build files or log4j configuration files. See SuppressionFilter.
053 *   {@code
054 *   &lt;suppress checks="OrderedProperties"
055 *     files="log4j.properties|ResourceBundle/Bug.*.properties|logging.properties"/&gt;
056 *   }
057 * </p>
058 *
059 * <p>Known limitation: The key should not contain a newline.
060 * The string compare will work, but not the line number reporting.</p>
061 * <ul><li>
062 * Property {@code fileExtensions} - Specify the file extensions of the files to process.
063 * Type is {@code java.lang.String[]}.
064 * Default value is {@code .properties}.
065 * </li></ul>
066 *
067 * <p>
068 * Parent is {@code com.puppycrawl.tools.checkstyle.Checker}
069 * </p>
070 *
071 * <p>
072 * Violation Message Keys:
073 * </p>
074 * <ul>
075 * <li>
076 * {@code properties.notSorted.property}
077 * </li>
078 * <li>
079 * {@code unable.open.cause}
080 * </li>
081 * </ul>
082 *
083 * @since 8.22
084 */
085@StatelessCheck
086public class OrderedPropertiesCheck extends AbstractFileSetCheck {
087
088    /**
089     * Localization key for check violation.
090     */
091    public static final String MSG_KEY = "properties.notSorted.property";
092    /**
093     * Localization key for IO exception occurred on file open.
094     */
095    public static final String MSG_IO_EXCEPTION_KEY = "unable.open.cause";
096    /**
097     * Pattern matching single space.
098     */
099    private static final Pattern SPACE_PATTERN = Pattern.compile(" ");
100
101    /**
102     * Construct the check with default values.
103     */
104    public OrderedPropertiesCheck() {
105        setFileExtensions("properties");
106    }
107
108    /**
109     * Setter to specify the file extensions of the files to process.
110     *
111     * @param extensions the set of file extensions. A missing
112     *         initial '.' character of an extension is automatically added.
113     * @throws IllegalArgumentException is argument is null
114     */
115    @Override
116    public final void setFileExtensions(String... extensions) {
117        super.setFileExtensions(extensions);
118    }
119
120    /**
121     * Processes the file and check order.
122     *
123     * @param file the file to be processed
124     * @param fileText the contents of the file.
125     */
126    @Override
127    protected void processFiltered(File file, FileText fileText) {
128        final SequencedProperties properties = new SequencedProperties();
129        try (InputStream inputStream = Files.newInputStream(file.toPath())) {
130            properties.load(inputStream);
131        }
132        catch (IOException | IllegalArgumentException exc) {
133            log(1, MSG_IO_EXCEPTION_KEY, file.getPath(), exc.getLocalizedMessage());
134        }
135
136        String previousProp = "";
137        int startLineNo = 0;
138
139        final Iterator<Object> propertyIterator = properties.keys().asIterator();
140
141        while (propertyIterator.hasNext()) {
142
143            final String propKey = (String) propertyIterator.next();
144
145            if (String.CASE_INSENSITIVE_ORDER.compare(previousProp, propKey) > 0) {
146
147                final int lineNo = getLineNumber(startLineNo, fileText, previousProp, propKey);
148                log(lineNo + 1, MSG_KEY, propKey, previousProp);
149                // start searching at position of the last reported validation
150                startLineNo = lineNo;
151            }
152
153            previousProp = propKey;
154        }
155    }
156
157    /**
158     * Method returns the index number where the key is detected (starting at 0).
159     * To assure that we get the correct line it starts at the point
160     * of the last occurrence.
161     * Also, the previousProp should be in file before propKey.
162     *
163     * @param startLineNo start searching at line
164     * @param fileText {@link FileText} object contains the lines to process
165     * @param previousProp key name found last iteration, works only if valid
166     * @param propKey key name to look for
167     * @return index number of first occurrence. If no key found in properties file, 0 is returned
168     */
169    private static int getLineNumber(int startLineNo, FileText fileText,
170                                     String previousProp, String propKey) {
171        final int indexOfPreviousProp = getIndex(startLineNo, fileText, previousProp);
172        return getIndex(indexOfPreviousProp, fileText, propKey);
173    }
174
175    /**
176     * Inner method to get the index number of the position of keyName.
177     *
178     * @param startLineNo start searching at line
179     * @param fileText {@link FileText} object contains the lines to process
180     * @param keyName key name to look for
181     * @return index number of first occurrence. If no key found in properties file, 0 is returned
182     */
183    private static int getIndex(int startLineNo, FileText fileText, String keyName) {
184        final Pattern keyPattern = getKeyPattern(keyName);
185        int indexNumber = 0;
186        final Matcher matcher = keyPattern.matcher("");
187        for (int index = startLineNo; index < fileText.size(); index++) {
188            final String line = fileText.get(index);
189            matcher.reset(line);
190            if (matcher.matches()) {
191                indexNumber = index;
192                break;
193            }
194        }
195        return indexNumber;
196    }
197
198    /**
199     * Method returns regular expression pattern given key name.
200     *
201     * @param keyName
202     *            key name to look for
203     * @return regular expression pattern given key name
204     */
205    private static Pattern getKeyPattern(String keyName) {
206        final String keyPatternString = "^" + SPACE_PATTERN.matcher(keyName)
207                .replaceAll(Matcher.quoteReplacement("\\\\ ")) + "[\\s:=].*";
208        return Pattern.compile(keyPatternString);
209    }
210
211    /**
212     * Private property implementation that keeps order of properties like in file.
213     *
214     * @noinspection ClassExtendsConcreteCollection
215     * @noinspectionreason ClassExtendsConcreteCollection - we require order from
216     *      file to be maintained by {@code put} method
217     */
218    private static final class SequencedProperties extends Properties {
219
220        /** A unique serial version identifier. */
221        @Serial
222        private static final long serialVersionUID = 1L;
223
224        /**
225         * Holding the keys in the same order as in the file.
226         */
227        private final List<Object> keyList = new ArrayList<>();
228
229        /**
230         * Returns a copy of the keys.
231         */
232        @Override
233        public Enumeration<Object> keys() {
234            return Collections.enumeration(keyList);
235        }
236
237        /**
238         * Puts the value into list by its key.
239         *
240         * @param key the hashtable key
241         * @param value the value
242         * @return the previous value of the specified key in this hashtable,
243         *      or null if it did not have one
244         * @throws NullPointerException - if the key or value is null
245         */
246        @Override
247        public synchronized Object put(Object key, Object value) {
248            keyList.add(key);
249
250            return null;
251        }
252    }
253}