View Javadoc
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 }