1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2025 the original author or authors.
4 //
5 // This library is free software; you can redistribute it and/or
6 // modify it under the terms of the GNU Lesser General Public
7 // License as published by the Free Software Foundation; either
8 // version 2.1 of the License, or (at your option) any later version.
9 //
10 // This library is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 // Lesser General Public License for more details.
14 //
15 // You should have received a copy of the GNU Lesser General Public
16 // License along with this library; if not, write to the Free Software
17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 ///////////////////////////////////////////////////////////////////////////////////////////////
19
20 package com.puppycrawl.tools.checkstyle.checks;
21
22 import java.io.File;
23 import java.io.IOException;
24 import java.io.InputStream;
25 import java.io.Serial;
26 import java.nio.file.Files;
27 import java.util.ArrayList;
28 import java.util.Collections;
29 import java.util.Enumeration;
30 import java.util.Iterator;
31 import java.util.List;
32 import java.util.Properties;
33 import java.util.regex.Matcher;
34 import java.util.regex.Pattern;
35
36 import com.puppycrawl.tools.checkstyle.StatelessCheck;
37 import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
38 import com.puppycrawl.tools.checkstyle.api.FileText;
39
40 /**
41 * <div>
42 * Detects if keys in properties files are in correct order.
43 * </div>
44 *
45 * <p>
46 * Rationale: Sorted properties make it easy for people to find required properties by name
47 * in file. This makes it easier to merge. While there are no problems at runtime.
48 * This check is valuable only on files with string resources where order of lines
49 * does not matter at all, but this can be improved.
50 * E.g.: checkstyle/src/main/resources/com/puppycrawl/tools/checkstyle/messages.properties
51 * You may suppress warnings of this check for files that have a logical structure like
52 * build files or log4j configuration files. See SuppressionFilter.
53 * {@code
54 * <suppress checks="OrderedProperties"
55 * files="log4j.properties|ResourceBundle/Bug.*.properties|logging.properties"/>
56 * }
57 * </p>
58 *
59 * <p>Known limitation: The key should not contain a newline.
60 * The string compare will work, but not the line number reporting.</p>
61 * <ul><li>
62 * Property {@code fileExtensions} - Specify the file extensions of the files to process.
63 * Type is {@code java.lang.String[]}.
64 * Default value is {@code .properties}.
65 * </li></ul>
66 *
67 * <p>
68 * Parent is {@code com.puppycrawl.tools.checkstyle.Checker}
69 * </p>
70 *
71 * <p>
72 * Violation Message Keys:
73 * </p>
74 * <ul>
75 * <li>
76 * {@code properties.notSorted.property}
77 * </li>
78 * <li>
79 * {@code unable.open.cause}
80 * </li>
81 * </ul>
82 *
83 * @since 8.22
84 */
85 @StatelessCheck
86 public class OrderedPropertiesCheck extends AbstractFileSetCheck {
87
88 /**
89 * Localization key for check violation.
90 */
91 public static final String MSG_KEY = "properties.notSorted.property";
92 /**
93 * Localization key for IO exception occurred on file open.
94 */
95 public static final String MSG_IO_EXCEPTION_KEY = "unable.open.cause";
96 /**
97 * Pattern matching single space.
98 */
99 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 }