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     * Processes the file and check order.
110     *
111     * @param file the file to be processed
112     * @param fileText the contents of the file.
113     */
114    @Override
115    protected void processFiltered(File file, FileText fileText) {
116        final SequencedProperties properties = new SequencedProperties();
117        try (InputStream inputStream = Files.newInputStream(file.toPath())) {
118            properties.load(inputStream);
119        }
120        catch (IOException | IllegalArgumentException exc) {
121            log(1, MSG_IO_EXCEPTION_KEY, file.getPath(), exc.getLocalizedMessage());
122        }
123
124        String previousProp = "";
125        int startLineNo = 0;
126
127        final Iterator<Object> propertyIterator = properties.keys().asIterator();
128
129        while (propertyIterator.hasNext()) {
130
131            final String propKey = (String) propertyIterator.next();
132
133            if (String.CASE_INSENSITIVE_ORDER.compare(previousProp, propKey) > 0) {
134
135                final int lineNo = getLineNumber(startLineNo, fileText, previousProp, propKey);
136                log(lineNo + 1, MSG_KEY, propKey, previousProp);
137                // start searching at position of the last reported validation
138                startLineNo = lineNo;
139            }
140
141            previousProp = propKey;
142        }
143    }
144
145    /**
146     * Method returns the index number where the key is detected (starting at 0).
147     * To assure that we get the correct line it starts at the point
148     * of the last occurrence.
149     * Also, the previousProp should be in file before propKey.
150     *
151     * @param startLineNo start searching at line
152     * @param fileText {@link FileText} object contains the lines to process
153     * @param previousProp key name found last iteration, works only if valid
154     * @param propKey key name to look for
155     * @return index number of first occurrence. If no key found in properties file, 0 is returned
156     */
157    private static int getLineNumber(int startLineNo, FileText fileText,
158                                     String previousProp, String propKey) {
159        final int indexOfPreviousProp = getIndex(startLineNo, fileText, previousProp);
160        return getIndex(indexOfPreviousProp, fileText, propKey);
161    }
162
163    /**
164     * Inner method to get the index number of the position of keyName.
165     *
166     * @param startLineNo start searching at line
167     * @param fileText {@link FileText} object contains the lines to process
168     * @param keyName key name to look for
169     * @return index number of first occurrence. If no key found in properties file, 0 is returned
170     */
171    private static int getIndex(int startLineNo, FileText fileText, String keyName) {
172        final Pattern keyPattern = getKeyPattern(keyName);
173        int indexNumber = 0;
174        final Matcher matcher = keyPattern.matcher("");
175        for (int index = startLineNo; index < fileText.size(); index++) {
176            final String line = fileText.get(index);
177            matcher.reset(line);
178            if (matcher.matches()) {
179                indexNumber = index;
180                break;
181            }
182        }
183        return indexNumber;
184    }
185
186    /**
187     * Method returns regular expression pattern given key name.
188     *
189     * @param keyName
190     *            key name to look for
191     * @return regular expression pattern given key name
192     */
193    private static Pattern getKeyPattern(String keyName) {
194        final String keyPatternString = "^" + SPACE_PATTERN.matcher(keyName)
195                .replaceAll(Matcher.quoteReplacement("\\\\ ")) + "[\\s:=].*";
196        return Pattern.compile(keyPatternString);
197    }
198
199    /**
200     * Private property implementation that keeps order of properties like in file.
201     *
202     * @noinspection ClassExtendsConcreteCollection
203     * @noinspectionreason ClassExtendsConcreteCollection - we require order from
204     *      file to be maintained by {@code put} method
205     */
206    private static final class SequencedProperties extends Properties {
207
208        /** A unique serial version identifier. */
209        @Serial
210        private static final long serialVersionUID = 1L;
211
212        /**
213         * Holding the keys in the same order as in the file.
214         */
215        private final List<Object> keyList = new ArrayList<>();
216
217        /**
218         * Returns a copy of the keys.
219         */
220        @Override
221        public Enumeration<Object> keys() {
222            return Collections.enumeration(keyList);
223        }
224
225        /**
226         * Puts the value into list by its key.
227         *
228         * @param key the hashtable key
229         * @param value the value
230         * @return the previous value of the specified key in this hashtable,
231         *      or null if it did not have one
232         * @throws NullPointerException - if the key or value is null
233         */
234        @Override
235        public synchronized Object put(Object key, Object value) {
236            keyList.add(key);
237
238            return null;
239        }
240    }
241}