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.javadoc;
21
22 import java.util.ArrayList;
23 import java.util.Collection;
24 import java.util.List;
25 import java.util.Set;
26 import java.util.regex.Matcher;
27 import java.util.regex.Pattern;
28
29 import com.puppycrawl.tools.checkstyle.StatelessCheck;
30 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
31 import com.puppycrawl.tools.checkstyle.api.DetailAST;
32 import com.puppycrawl.tools.checkstyle.api.FileContents;
33 import com.puppycrawl.tools.checkstyle.api.Scope;
34 import com.puppycrawl.tools.checkstyle.api.TextBlock;
35 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
36 import com.puppycrawl.tools.checkstyle.utils.AnnotationUtil;
37 import com.puppycrawl.tools.checkstyle.utils.CheckUtil;
38 import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
39 import com.puppycrawl.tools.checkstyle.utils.JavadocUtil;
40 import com.puppycrawl.tools.checkstyle.utils.ScopeUtil;
41 import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
42
43 /**
44 * <div>
45 * Checks the Javadoc comments for type definitions. By default, does
46 * not check for author or version tags. The scope to verify is specified using the {@code Scope}
47 * class and defaults to {@code Scope.PRIVATE}. To verify another scope, set property
48 * scope to one of the {@code Scope} constants. To define the format for an author
49 * tag or a version tag, set property authorFormat or versionFormat respectively to a
50 * <a href="https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html">
51 * pattern</a>.
52 * </div>
53 *
54 * <p>
55 * Does not perform checks for author and version tags for inner classes,
56 * as they should be redundant because of outer class.
57 * </p>
58 *
59 * <p>
60 * Does not perform checks for type definitions that do not have any Javadoc comments.
61 * </p>
62 *
63 * <p>
64 * Error messages about type parameters and record components for which no param tags are present
65 * can be suppressed by defining property {@code allowMissingParamTags}.
66 * </p>
67 *
68 * @since 3.0
69 */
70 @StatelessCheck
71 public class JavadocTypeCheck
72 extends AbstractCheck {
73
74 /**
75 * A key is pointing to the warning message text in "messages.properties"
76 * file.
77 */
78 public static final String MSG_UNKNOWN_TAG = "javadoc.unknownTag";
79
80 /**
81 * A key is pointing to the warning message text in "messages.properties"
82 * file.
83 */
84 public static final String MSG_TAG_FORMAT = "type.tagFormat";
85
86 /**
87 * A key is pointing to the warning message text in "messages.properties"
88 * file.
89 */
90 public static final String MSG_MISSING_TAG = "type.missingTag";
91
92 /**
93 * A key is pointing to the warning message text in "messages.properties"
94 * file.
95 */
96 public static final String MSG_UNUSED_TAG = "javadoc.unusedTag";
97
98 /**
99 * A key is pointing to the warning message text in "messages.properties"
100 * file.
101 */
102 public static final String MSG_UNUSED_TAG_GENERAL = "javadoc.unusedTagGeneral";
103
104 /** Open angle bracket literal. */
105 private static final String OPEN_ANGLE_BRACKET = "<";
106
107 /** Close angle bracket literal. */
108 private static final String CLOSE_ANGLE_BRACKET = ">";
109
110 /** Space literal. */
111 private static final String SPACE = " ";
112
113 /** Pattern to match type name within angle brackets in javadoc param tag. */
114 private static final Pattern TYPE_NAME_IN_JAVADOC_TAG =
115 Pattern.compile("^<([^>]+)");
116
117 /** Pattern to split type name field in javadoc param tag. */
118 private static final Pattern TYPE_NAME_IN_JAVADOC_TAG_SPLITTER =
119 Pattern.compile("\\s+");
120
121 /** Specify the visibility scope where Javadoc comments are checked. */
122 private Scope scope = Scope.PRIVATE;
123 /** Specify the visibility scope where Javadoc comments are not checked. */
124 private Scope excludeScope;
125 /** Specify the pattern for {@code @author} tag. */
126 private Pattern authorFormat;
127 /** Specify the pattern for {@code @version} tag. */
128 private Pattern versionFormat;
129 /**
130 * Control whether to ignore violations when a class has type parameters but
131 * does not have matching param tags in the Javadoc.
132 */
133 private boolean allowMissingParamTags;
134 /** Control whether to ignore violations when a Javadoc tag is not recognised. */
135 private boolean allowUnknownTags;
136
137 /**
138 * Specify annotations that allow skipping validation at all.
139 * Only short names are allowed, e.g. {@code Generated}.
140 */
141 private Set<String> allowedAnnotations = Set.of("Generated");
142
143 /**
144 * Setter to specify the visibility scope where Javadoc comments are checked.
145 *
146 * @param scope a scope.
147 * @since 3.0
148 */
149 public void setScope(Scope scope) {
150 this.scope = scope;
151 }
152
153 /**
154 * Setter to specify the visibility scope where Javadoc comments are not checked.
155 *
156 * @param excludeScope a scope.
157 * @since 3.4
158 */
159 public void setExcludeScope(Scope excludeScope) {
160 this.excludeScope = excludeScope;
161 }
162
163 /**
164 * Setter to specify the pattern for {@code @author} tag.
165 *
166 * @param pattern a pattern.
167 * @since 3.0
168 */
169 public void setAuthorFormat(Pattern pattern) {
170 authorFormat = pattern;
171 }
172
173 /**
174 * Setter to specify the pattern for {@code @version} tag.
175 *
176 * @param pattern a pattern.
177 * @since 3.0
178 */
179 public void setVersionFormat(Pattern pattern) {
180 versionFormat = pattern;
181 }
182
183 /**
184 * Setter to control whether to ignore violations when a class has type parameters but
185 * does not have matching param tags in the Javadoc.
186 *
187 * @param flag a {@code Boolean} value
188 * @since 4.0
189 */
190 public void setAllowMissingParamTags(boolean flag) {
191 allowMissingParamTags = flag;
192 }
193
194 /**
195 * Setter to control whether to ignore violations when a Javadoc tag is not recognised.
196 *
197 * @param flag a {@code Boolean} value
198 * @since 5.1
199 */
200 public void setAllowUnknownTags(boolean flag) {
201 allowUnknownTags = flag;
202 }
203
204 /**
205 * Setter to specify annotations that allow skipping validation at all.
206 * Only short names are allowed, e.g. {@code Generated}.
207 *
208 * @param userAnnotations user's value.
209 * @since 8.15
210 */
211 public void setAllowedAnnotations(String... userAnnotations) {
212 allowedAnnotations = Set.of(userAnnotations);
213 }
214
215 @Override
216 public int[] getDefaultTokens() {
217 return getAcceptableTokens();
218 }
219
220 @Override
221 public int[] getAcceptableTokens() {
222 return new int[] {
223 TokenTypes.INTERFACE_DEF,
224 TokenTypes.CLASS_DEF,
225 TokenTypes.ENUM_DEF,
226 TokenTypes.ANNOTATION_DEF,
227 TokenTypes.RECORD_DEF,
228 };
229 }
230
231 @Override
232 public int[] getRequiredTokens() {
233 return CommonUtil.EMPTY_INT_ARRAY;
234 }
235
236 // suppress deprecation until https://github.com/checkstyle/checkstyle/issues/11166
237 @Override
238 @SuppressWarnings("deprecation")
239 public void visitToken(DetailAST ast) {
240 if (shouldCheck(ast)) {
241 final FileContents contents = getFileContents();
242 final int lineNo = ast.getLineNo();
243 final TextBlock textBlock = contents.getJavadocBefore(lineNo);
244 if (textBlock != null) {
245 final List<JavadocTag> tags = getJavadocTags(textBlock);
246 if (ScopeUtil.isOuterMostType(ast)) {
247 // don't check author/version for inner classes
248 checkTag(ast, tags, JavadocTagInfo.AUTHOR.getName(),
249 authorFormat);
250 checkTag(ast, tags, JavadocTagInfo.VERSION.getName(),
251 versionFormat);
252 }
253
254 final List<String> typeParamNames =
255 CheckUtil.getTypeParameterNames(ast);
256 final List<String> recordComponentNames =
257 getRecordComponentNames(ast);
258
259 if (!allowMissingParamTags) {
260
261 typeParamNames.forEach(typeParamName -> {
262 checkTypeParamTag(ast, tags, typeParamName);
263 });
264
265 recordComponentNames.forEach(componentName -> {
266 checkComponentParamTag(ast, tags, componentName);
267 });
268 }
269
270 checkUnusedParamTags(tags, typeParamNames, recordComponentNames);
271 }
272 }
273 }
274
275 /**
276 * Whether we should check this node.
277 *
278 * @param ast a given node.
279 * @return whether we should check a given node.
280 */
281 private boolean shouldCheck(DetailAST ast) {
282 final Scope surroundingScope = ScopeUtil.getSurroundingScope(ast);
283
284 return surroundingScope.isIn(scope)
285 && (excludeScope == null || !surroundingScope.isIn(excludeScope))
286 && !AnnotationUtil.containsAnnotation(ast, allowedAnnotations);
287 }
288
289 /**
290 * Gets all standalone tags from a given javadoc.
291 *
292 * @param textBlock the Javadoc comment to process.
293 * @return all standalone tags from the given javadoc.
294 */
295 private List<JavadocTag> getJavadocTags(TextBlock textBlock) {
296 final JavadocTags tags = JavadocUtil.getJavadocTags(textBlock,
297 JavadocUtil.JavadocTagType.BLOCK);
298 if (!allowUnknownTags) {
299 tags.getInvalidTags().forEach(tag -> {
300 log(tag.getLine(), tag.getCol(), MSG_UNKNOWN_TAG, tag.getName());
301 });
302 }
303 return tags.getValidTags();
304 }
305
306 /**
307 * Verifies that a type definition has a required tag.
308 *
309 * @param ast the AST node for the type definition.
310 * @param tags tags from the Javadoc comment for the type definition.
311 * @param tagName the required tag name.
312 * @param formatPattern regexp for the tag value.
313 */
314 private void checkTag(DetailAST ast, Iterable<JavadocTag> tags, String tagName,
315 Pattern formatPattern) {
316 if (formatPattern != null) {
317 boolean hasTag = false;
318 final String tagPrefix = "@";
319
320 for (final JavadocTag tag :tags) {
321 if (tag.getTagName().equals(tagName)) {
322 hasTag = true;
323 if (!formatPattern.matcher(tag.getFirstArg()).find()) {
324 log(ast, MSG_TAG_FORMAT, tagPrefix + tagName, formatPattern.pattern());
325 }
326 }
327 }
328 if (!hasTag) {
329 log(ast, MSG_MISSING_TAG, tagPrefix + tagName);
330 }
331 }
332 }
333
334 /**
335 * Verifies that a record definition has the specified param tag for
336 * the specified record component name.
337 *
338 * @param ast the AST node for the record definition.
339 * @param tags tags from the Javadoc comment for the record definition.
340 * @param recordComponentName the name of the type parameter
341 */
342 private void checkComponentParamTag(DetailAST ast,
343 Collection<JavadocTag> tags,
344 String recordComponentName) {
345
346 final boolean found = tags
347 .stream()
348 .filter(JavadocTag::isParamTag)
349 .anyMatch(tag -> tag.getFirstArg().indexOf(recordComponentName) == 0);
350
351 if (!found) {
352 log(ast, MSG_MISSING_TAG, JavadocTagInfo.PARAM.getText()
353 + SPACE + recordComponentName);
354 }
355 }
356
357 /**
358 * Verifies that a type definition has the specified param tag for
359 * the specified type parameter name.
360 *
361 * @param ast the AST node for the type definition.
362 * @param tags tags from the Javadoc comment for the type definition.
363 * @param typeParamName the name of the type parameter
364 */
365 private void checkTypeParamTag(DetailAST ast,
366 Collection<JavadocTag> tags, String typeParamName) {
367 final String typeParamNameWithBrackets =
368 OPEN_ANGLE_BRACKET + typeParamName + CLOSE_ANGLE_BRACKET;
369
370 final boolean found = tags
371 .stream()
372 .filter(JavadocTag::isParamTag)
373 .anyMatch(tag -> tag.getFirstArg().indexOf(typeParamNameWithBrackets) == 0);
374
375 if (!found) {
376 log(ast, MSG_MISSING_TAG, JavadocTagInfo.PARAM.getText()
377 + SPACE + typeParamNameWithBrackets);
378 }
379 }
380
381 /**
382 * Checks for unused param tags for type parameters and record components.
383 *
384 * @param tags tags from the Javadoc comment for the type definition
385 * @param typeParamNames names of type parameters
386 * @param recordComponentNames record component names in this definition
387 */
388 private void checkUnusedParamTags(
389 List<JavadocTag> tags,
390 List<String> typeParamNames,
391 List<String> recordComponentNames) {
392
393 for (final JavadocTag tag: tags) {
394 if (tag.isParamTag()) {
395 final String paramName = extractParamNameFromTag(tag);
396 final boolean found = typeParamNames.contains(paramName)
397 || recordComponentNames.contains(paramName);
398
399 if (!found) {
400 if (paramName.isEmpty()) {
401 log(tag.getLineNo(), tag.getColumnNo(), MSG_UNUSED_TAG_GENERAL);
402 }
403 else {
404 final String actualParamName =
405 TYPE_NAME_IN_JAVADOC_TAG_SPLITTER.split(tag.getFirstArg())[0];
406 log(tag.getLineNo(), tag.getColumnNo(),
407 MSG_UNUSED_TAG,
408 JavadocTagInfo.PARAM.getText(), actualParamName);
409 }
410 }
411 }
412 }
413
414 }
415
416 /**
417 * Extracts parameter name from tag.
418 *
419 * @param tag javadoc tag to extract parameter name
420 * @return extracts type parameter name from tag
421 */
422 private static String extractParamNameFromTag(JavadocTag tag) {
423 final String typeParamName;
424 final Matcher matchInAngleBrackets =
425 TYPE_NAME_IN_JAVADOC_TAG.matcher(tag.getFirstArg());
426 if (matchInAngleBrackets.find()) {
427 typeParamName = matchInAngleBrackets.group(1).trim();
428 }
429 else {
430 typeParamName = TYPE_NAME_IN_JAVADOC_TAG_SPLITTER.split(tag.getFirstArg())[0];
431 }
432 return typeParamName;
433 }
434
435 /**
436 * Collects the record components in a record definition.
437 *
438 * @param node the possible record definition ast.
439 * @return the record components in this record definition.
440 */
441 private static List<String> getRecordComponentNames(DetailAST node) {
442 final DetailAST components = node.findFirstToken(TokenTypes.RECORD_COMPONENTS);
443 final List<String> componentList = new ArrayList<>();
444
445 if (components != null) {
446 TokenUtil.forEachChild(components,
447 TokenTypes.RECORD_COMPONENT_DEF, component -> {
448 final DetailAST ident = component.findFirstToken(TokenTypes.IDENT);
449 componentList.add(ident.getText());
450 });
451 }
452
453 return componentList;
454 }
455 }