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.design;
021
022import java.util.ArrayList;
023import java.util.Collection;
024import java.util.HashSet;
025import java.util.List;
026import java.util.Set;
027import java.util.regex.Pattern;
028import java.util.stream.Collectors;
029
030import com.puppycrawl.tools.checkstyle.FileStatefulCheck;
031import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
032import com.puppycrawl.tools.checkstyle.api.DetailAST;
033import com.puppycrawl.tools.checkstyle.api.FullIdent;
034import com.puppycrawl.tools.checkstyle.api.TokenTypes;
035import com.puppycrawl.tools.checkstyle.utils.AnnotationUtil;
036import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
037import com.puppycrawl.tools.checkstyle.utils.ScopeUtil;
038
039/**
040 * <div>
041 * Checks visibility of class members. Only static final, immutable or annotated
042 * by specified annotation members may be public;
043 * other class members must be private unless the property {@code protectedAllowed}
044 * or {@code packageAllowed} is set.
045 * </div>
046 *
047 * <p>
048 * Public members are not flagged if the name matches the public
049 * member regular expression (contains {@code "^serialVersionUID$"} by
050 * default).
051 * </p>
052 *
053 * <p>
054 * Note that Checkstyle 2 used to include {@code "^f[A-Z][a-zA-Z0-9]*$"} in the default pattern
055 * to allow names used in container-managed persistence for Enterprise JavaBeans (EJB) 1.1 with
056 * the default settings. With EJB 2.0 it is no longer necessary to have public access for
057 * persistent fields, so the default has been changed.
058 * </p>
059 *
060 * <p>
061 * Rationale: Enforce encapsulation.
062 * </p>
063 *
064 * <p>
065 * Check also has options making it less strict:
066 * </p>
067 *
068 * <p>
069 * <b>ignoreAnnotationCanonicalNames</b> - the list of annotations which ignore
070 * variables in consideration. If user want to provide short annotation name that
071 * type will match to any named the same type without consideration of package.
072 * </p>
073 *
074 * <p>
075 * <b>allowPublicFinalFields</b> - which allows public final fields.
076 * </p>
077 *
078 * <p>
079 * <b>allowPublicImmutableFields</b> - which allows immutable fields to be
080 * declared as public if defined in final class.
081 * </p>
082 *
083 * <p>
084 * Field is known to be immutable if:
085 * </p>
086 * <ul>
087 * <li>It's declared as final</li>
088 * <li>Has either a primitive type or instance of class user defined to be immutable
089 * (such as String, ImmutableCollection from Guava, etc.)</li>
090 * </ul>
091 *
092 * <p>
093 * Classes known to be immutable are listed in <b>immutableClassCanonicalNames</b>
094 * by their canonical names.
095 * </p>
096 *
097 * <p>
098 * Property Rationale: Forcing all fields of class to have private modifier by default is
099 * good in most cases, but in some cases it drawbacks in too much boilerplate get/set code.
100 * One of such cases are immutable classes.
101 * </p>
102 *
103 * <p>
104 * Restriction: Check doesn't check if class is immutable, there's no checking
105 * if accessory methods are missing and all fields are immutable, we only check
106 * if current field is immutable or final.
107 * Under the flag <b>allowPublicImmutableFields</b>, the enclosing class must
108 * also be final, to encourage immutability.
109 * Under the flag <b>allowPublicFinalFields</b>, the final modifier
110 * on the enclosing class is optional.
111 * </p>
112 *
113 * <p>
114 * Star imports are out of scope of this Check. So if one of type imported via
115 * star import collides with user specified one by its short name - there
116 * won't be Check's violation.
117 * </p>
118 *
119 * @since 3.0
120 */
121@FileStatefulCheck
122public class VisibilityModifierCheck
123    extends AbstractCheck {
124
125    /**
126     * A key is pointing to the warning message text in "messages.properties"
127     * file.
128     */
129    public static final String MSG_KEY = "variable.notPrivate";
130
131    /** Default immutable types canonical names. */
132    private static final Set<String> DEFAULT_IMMUTABLE_TYPES = Set.of(
133        "java.lang.String",
134        "java.lang.Integer",
135        "java.lang.Byte",
136        "java.lang.Character",
137        "java.lang.Short",
138        "java.lang.Boolean",
139        "java.lang.Long",
140        "java.lang.Double",
141        "java.lang.Float",
142        "java.lang.StackTraceElement",
143        "java.math.BigInteger",
144        "java.math.BigDecimal",
145        "java.io.File",
146        "java.util.Locale",
147        "java.util.UUID",
148        "java.net.URL",
149        "java.net.URI",
150        "java.net.Inet4Address",
151        "java.net.Inet6Address",
152        "java.net.InetSocketAddress"
153    );
154
155    /** Default ignore annotations canonical names. */
156    private static final Set<String> DEFAULT_IGNORE_ANNOTATIONS = Set.of(
157        "org.junit.Rule",
158        "org.junit.ClassRule",
159        "com.google.common.annotations.VisibleForTesting"
160    );
161
162    /** Name for 'public' access modifier. */
163    private static final String PUBLIC_ACCESS_MODIFIER = "public";
164
165    /** Name for 'private' access modifier. */
166    private static final String PRIVATE_ACCESS_MODIFIER = "private";
167
168    /** Name for 'protected' access modifier. */
169    private static final String PROTECTED_ACCESS_MODIFIER = "protected";
170
171    /** Name for implicit 'package' access modifier. */
172    private static final String PACKAGE_ACCESS_MODIFIER = "package";
173
174    /** Name for 'static' keyword. */
175    private static final String STATIC_KEYWORD = "static";
176
177    /** Name for 'final' keyword. */
178    private static final String FINAL_KEYWORD = "final";
179
180    /** Contains explicit access modifiers. */
181    private static final String[] EXPLICIT_MODS = {
182        PUBLIC_ACCESS_MODIFIER,
183        PRIVATE_ACCESS_MODIFIER,
184        PROTECTED_ACCESS_MODIFIER,
185    };
186
187    /**
188     * Specify pattern for public members that should be ignored.
189     */
190    private Pattern publicMemberPattern = Pattern.compile("^serialVersionUID$");
191
192    /** Set of ignore annotations short names. */
193    private Set<String> ignoreAnnotationShortNames;
194
195    /** Set of immutable classes short names. */
196    private Set<String> immutableClassShortNames;
197
198    /**
199     * Specify annotations canonical names which ignore variables in
200     * consideration.
201     */
202    private Set<String> ignoreAnnotationCanonicalNames = DEFAULT_IGNORE_ANNOTATIONS;
203
204    /** Control whether protected members are allowed. */
205    private boolean protectedAllowed;
206
207    /** Control whether package visible members are allowed. */
208    private boolean packageAllowed;
209
210    /** Allow immutable fields to be declared as public if defined in final class. */
211    private boolean allowPublicImmutableFields;
212
213    /** Allow final fields to be declared as public. */
214    private boolean allowPublicFinalFields;
215
216    /** Specify immutable classes canonical names. */
217    private Set<String> immutableClassCanonicalNames = DEFAULT_IMMUTABLE_TYPES;
218
219    /**
220     * Setter to specify annotations canonical names which ignore variables
221     * in consideration.
222     *
223     * @param annotationNames array of ignore annotations canonical names.
224     * @since 6.5
225     */
226    public void setIgnoreAnnotationCanonicalNames(String... annotationNames) {
227        ignoreAnnotationCanonicalNames = Set.of(annotationNames);
228    }
229
230    /**
231     * Setter to control whether protected members are allowed.
232     *
233     * @param protectedAllowed whether protected members are allowed
234     * @since 3.0
235     */
236    public void setProtectedAllowed(boolean protectedAllowed) {
237        this.protectedAllowed = protectedAllowed;
238    }
239
240    /**
241     * Setter to control whether package visible members are allowed.
242     *
243     * @param packageAllowed whether package visible members are allowed
244     * @since 3.0
245     */
246    public void setPackageAllowed(boolean packageAllowed) {
247        this.packageAllowed = packageAllowed;
248    }
249
250    /**
251     * Setter to specify pattern for public members that should be ignored.
252     *
253     * @param pattern
254     *        pattern for public members to ignore.
255     * @since 3.0
256     */
257    public void setPublicMemberPattern(Pattern pattern) {
258        publicMemberPattern = pattern;
259    }
260
261    /**
262     * Setter to allow immutable fields to be declared as public if defined in final class.
263     *
264     * @param allow user's value.
265     * @since 6.4
266     */
267    public void setAllowPublicImmutableFields(boolean allow) {
268        allowPublicImmutableFields = allow;
269    }
270
271    /**
272     * Setter to allow final fields to be declared as public.
273     *
274     * @param allow user's value.
275     * @since 7.0
276     */
277    public void setAllowPublicFinalFields(boolean allow) {
278        allowPublicFinalFields = allow;
279    }
280
281    /**
282     * Setter to specify immutable classes canonical names.
283     *
284     * @param classNames array of immutable types canonical names.
285     * @since 6.4.1
286     */
287    public void setImmutableClassCanonicalNames(String... classNames) {
288        immutableClassCanonicalNames = Set.of(classNames);
289    }
290
291    @Override
292    public int[] getDefaultTokens() {
293        return getRequiredTokens();
294    }
295
296    @Override
297    public int[] getAcceptableTokens() {
298        return getRequiredTokens();
299    }
300
301    @Override
302    public int[] getRequiredTokens() {
303        return new int[] {
304            TokenTypes.VARIABLE_DEF,
305            TokenTypes.IMPORT,
306        };
307    }
308
309    @Override
310    public void beginTree(DetailAST rootAst) {
311        immutableClassShortNames = getClassShortNames(immutableClassCanonicalNames);
312        ignoreAnnotationShortNames = getClassShortNames(ignoreAnnotationCanonicalNames);
313    }
314
315    @Override
316    public void visitToken(DetailAST ast) {
317        switch (ast.getType()) {
318            case TokenTypes.VARIABLE_DEF -> {
319                if (!isAnonymousClassVariable(ast)) {
320                    visitVariableDef(ast);
321                }
322            }
323            case TokenTypes.IMPORT -> visitImport(ast);
324            default -> {
325                final String exceptionMsg = "Unexpected token type: " + ast.getText();
326                throw new IllegalArgumentException(exceptionMsg);
327            }
328        }
329    }
330
331    /**
332     * Checks if current variable definition is definition of an anonymous class.
333     *
334     * @param variableDef {@link TokenTypes#VARIABLE_DEF VARIABLE_DEF}
335     * @return true if current variable definition is definition of an anonymous class.
336     */
337    private static boolean isAnonymousClassVariable(DetailAST variableDef) {
338        return variableDef.getParent().getType() != TokenTypes.OBJBLOCK;
339    }
340
341    /**
342     * Checks access modifier of given variable.
343     * If it is not proper according to Check - puts violation on it.
344     *
345     * @param variableDef variable to check.
346     */
347    private void visitVariableDef(DetailAST variableDef) {
348        final boolean inInterfaceOrAnnotationBlock =
349                ScopeUtil.isInInterfaceOrAnnotationBlock(variableDef);
350
351        if (!inInterfaceOrAnnotationBlock && !hasIgnoreAnnotation(variableDef)) {
352            final DetailAST varNameAST = variableDef.findFirstToken(TokenTypes.TYPE)
353                .getNextSibling();
354            final String varName = varNameAST.getText();
355            if (!hasProperAccessModifier(variableDef, varName)) {
356                log(varNameAST, MSG_KEY, varName);
357            }
358        }
359    }
360
361    /**
362     * Checks if variable def has ignore annotation.
363     *
364     * @param variableDef {@link TokenTypes#VARIABLE_DEF VARIABLE_DEF}
365     * @return true if variable def has ignore annotation.
366     */
367    private boolean hasIgnoreAnnotation(DetailAST variableDef) {
368        final DetailAST firstIgnoreAnnotation =
369                 findMatchingAnnotation(variableDef);
370        return firstIgnoreAnnotation != null;
371    }
372
373    /**
374     * Checks imported type. If type's canonical name was not specified in
375     * <b>immutableClassCanonicalNames</b>, but its short name collides with one from
376     * <b>immutableClassShortNames</b> - removes it from the last one.
377     *
378     * @param importAst {@link TokenTypes#IMPORT Import}
379     */
380    private void visitImport(DetailAST importAst) {
381        if (!isStarImport(importAst)) {
382            final String canonicalName = getCanonicalName(importAst);
383            final String shortName = getClassShortName(canonicalName);
384
385            // If imported canonical class name is not specified as allowed immutable class,
386            // but its short name collides with one of specified class - removes the short name
387            // from list to avoid names collision
388            if (!immutableClassCanonicalNames.contains(canonicalName)) {
389                immutableClassShortNames.remove(shortName);
390            }
391            if (!ignoreAnnotationCanonicalNames.contains(canonicalName)) {
392                ignoreAnnotationShortNames.remove(shortName);
393            }
394        }
395    }
396
397    /**
398     * Checks if current import is star import. E.g.:
399     *
400     * <p>
401     * {@code
402     * import java.util.*;
403     * }
404     * </p>
405     *
406     * @param importAst {@link TokenTypes#IMPORT Import}
407     * @return true if it is star import
408     */
409    private static boolean isStarImport(DetailAST importAst) {
410        boolean result = false;
411        DetailAST toVisit = importAst;
412        while (toVisit != null) {
413            toVisit = getNextSubTreeNode(toVisit, importAst);
414            if (toVisit != null && toVisit.getType() == TokenTypes.STAR) {
415                result = true;
416                break;
417            }
418        }
419        return result;
420    }
421
422    /**
423     * Checks if current variable has proper access modifier according to Check's options.
424     *
425     * @param variableDef Variable definition node.
426     * @param variableName Variable's name.
427     * @return true if variable has proper access modifier.
428     */
429    private boolean hasProperAccessModifier(DetailAST variableDef, String variableName) {
430        boolean result = true;
431
432        final String variableScope = getVisibilityScope(variableDef);
433
434        if (!PRIVATE_ACCESS_MODIFIER.equals(variableScope)) {
435            result =
436                isStaticFinalVariable(variableDef)
437                || packageAllowed && PACKAGE_ACCESS_MODIFIER.equals(variableScope)
438                || protectedAllowed && PROTECTED_ACCESS_MODIFIER.equals(variableScope)
439                || isIgnoredPublicMember(variableName, variableScope)
440                || isAllowedPublicField(variableDef);
441        }
442
443        return result;
444    }
445
446    /**
447     * Checks whether variable has static final modifiers.
448     *
449     * @param variableDef Variable definition node.
450     * @return true of variable has static final modifiers.
451     */
452    private static boolean isStaticFinalVariable(DetailAST variableDef) {
453        final Set<String> modifiers = getModifiers(variableDef);
454        return modifiers.contains(STATIC_KEYWORD)
455                && modifiers.contains(FINAL_KEYWORD);
456    }
457
458    /**
459     * Checks whether variable belongs to public members that should be ignored.
460     *
461     * @param variableName Variable's name.
462     * @param variableScope Variable's scope.
463     * @return true if variable belongs to public members that should be ignored.
464     */
465    private boolean isIgnoredPublicMember(String variableName, String variableScope) {
466        return PUBLIC_ACCESS_MODIFIER.equals(variableScope)
467            && publicMemberPattern.matcher(variableName).find();
468    }
469
470    /**
471     * Checks whether the variable satisfies the public field check.
472     *
473     * @param variableDef Variable definition node.
474     * @return true if allowed.
475     */
476    private boolean isAllowedPublicField(DetailAST variableDef) {
477        return allowPublicFinalFields && isFinalField(variableDef)
478            || allowPublicImmutableFields && isImmutableFieldDefinedInFinalClass(variableDef);
479    }
480
481    /**
482     * Checks whether immutable field is defined in final class.
483     *
484     * @param variableDef Variable definition node.
485     * @return true if immutable field is defined in final class.
486     */
487    private boolean isImmutableFieldDefinedInFinalClass(DetailAST variableDef) {
488        final DetailAST classDef = variableDef.getParent().getParent();
489        final Set<String> classModifiers = getModifiers(classDef);
490        return (classModifiers.contains(FINAL_KEYWORD) || classDef.getType() == TokenTypes.ENUM_DEF)
491                && isImmutableField(variableDef);
492    }
493
494    /**
495     * Returns the set of modifier Strings for a VARIABLE_DEF or CLASS_DEF AST.
496     *
497     * @param defAST AST for a variable or class definition.
498     * @return the set of modifier Strings for defAST.
499     */
500    private static Set<String> getModifiers(DetailAST defAST) {
501        final DetailAST modifiersAST = defAST.findFirstToken(TokenTypes.MODIFIERS);
502        final Set<String> modifiersSet = new HashSet<>();
503        if (modifiersAST != null) {
504            DetailAST modifier = modifiersAST.getFirstChild();
505            while (modifier != null) {
506                modifiersSet.add(modifier.getText());
507                modifier = modifier.getNextSibling();
508            }
509        }
510        return modifiersSet;
511    }
512
513    /**
514     * Returns the visibility scope for the variable.
515     *
516     * @param variableDef Variable definition node.
517     * @return one of "public", "private", "protected", "package"
518     */
519    private static String getVisibilityScope(DetailAST variableDef) {
520        final Set<String> modifiers = getModifiers(variableDef);
521        String accessModifier = PACKAGE_ACCESS_MODIFIER;
522        for (final String modifier : EXPLICIT_MODS) {
523            if (modifiers.contains(modifier)) {
524                accessModifier = modifier;
525                break;
526            }
527        }
528        return accessModifier;
529    }
530
531    /**
532     * Checks if current field is immutable:
533     * has final modifier and either a primitive type or instance of class
534     * known to be immutable (such as String, ImmutableCollection from Guava, etc.).
535     * Classes known to be immutable are listed in
536     * {@link VisibilityModifierCheck#immutableClassCanonicalNames}
537     *
538     * @param variableDef Field in consideration.
539     * @return true if field is immutable.
540     */
541    private boolean isImmutableField(DetailAST variableDef) {
542        boolean result = false;
543        if (isFinalField(variableDef)) {
544            final DetailAST type = variableDef.findFirstToken(TokenTypes.TYPE);
545            final boolean isCanonicalName = isCanonicalName(type);
546            final String typeName = getCanonicalName(type);
547            if (immutableClassShortNames.contains(typeName)
548                    || isCanonicalName && immutableClassCanonicalNames.contains(typeName)) {
549                final DetailAST typeArgs = getGenericTypeArgs(type, isCanonicalName);
550
551                if (typeArgs == null) {
552                    result = true;
553                }
554                else {
555                    final List<String> argsClassNames = getTypeArgsClassNames(typeArgs);
556                    result = areImmutableTypeArguments(argsClassNames);
557                }
558            }
559            else {
560                result = !isCanonicalName && isPrimitive(type);
561            }
562        }
563        return result;
564    }
565
566    /**
567     * Checks whether type definition is in canonical form.
568     *
569     * @param type type definition token.
570     * @return true if type definition is in canonical form.
571     */
572    private static boolean isCanonicalName(DetailAST type) {
573        return type.getFirstChild().getType() == TokenTypes.DOT;
574    }
575
576    /**
577     * Returns generic type arguments token.
578     *
579     * @param type type token.
580     * @param isCanonicalName whether type name is in canonical form.
581     * @return generic type arguments token.
582     */
583    private static DetailAST getGenericTypeArgs(DetailAST type, boolean isCanonicalName) {
584        final DetailAST typeArgs;
585        if (isCanonicalName) {
586            // if type class name is in canonical form, abstract tree has specific structure
587            typeArgs = type.getFirstChild().findFirstToken(TokenTypes.TYPE_ARGUMENTS);
588        }
589        else {
590            typeArgs = type.findFirstToken(TokenTypes.TYPE_ARGUMENTS);
591        }
592        return typeArgs;
593    }
594
595    /**
596     * Returns a list of type parameters class names.
597     *
598     * @param typeArgs type arguments token.
599     * @return a list of type parameters class names.
600     */
601    private static List<String> getTypeArgsClassNames(DetailAST typeArgs) {
602        final List<String> typeClassNames = new ArrayList<>();
603        DetailAST type = typeArgs.findFirstToken(TokenTypes.TYPE_ARGUMENT);
604        DetailAST sibling;
605        do {
606            final String typeName = getCanonicalName(type);
607            typeClassNames.add(typeName);
608            sibling = type.getNextSibling();
609            type = sibling.getNextSibling();
610        } while (sibling.getType() == TokenTypes.COMMA);
611        return typeClassNames;
612    }
613
614    /**
615     * Checks whether all generic type arguments are immutable.
616     * If at least one argument is mutable, we assume that the whole list of type arguments
617     * is mutable.
618     *
619     * @param typeArgsClassNames type arguments class names.
620     * @return true if all generic type arguments are immutable.
621     */
622    private boolean areImmutableTypeArguments(Collection<String> typeArgsClassNames) {
623        return typeArgsClassNames.stream().noneMatch(
624            typeName -> {
625                return !immutableClassShortNames.contains(typeName)
626                    && !immutableClassCanonicalNames.contains(typeName);
627            });
628    }
629
630    /**
631     * Checks whether current field is final.
632     *
633     * @param variableDef field in consideration.
634     * @return true if current field is final.
635     */
636    private static boolean isFinalField(DetailAST variableDef) {
637        final DetailAST modifiers = variableDef.findFirstToken(TokenTypes.MODIFIERS);
638        return modifiers.findFirstToken(TokenTypes.FINAL) != null;
639    }
640
641    /**
642     * Checks if current type is primitive type (int, short, float, boolean, double, etc.).
643     * As primitive types have special tokens for each one, such as:
644     * LITERAL_INT, LITERAL_BOOLEAN, etc.
645     * So, if type's identifier differs from {@link TokenTypes#IDENT IDENT} token - it's a
646     * primitive type.
647     *
648     * @param type Ast {@link TokenTypes#TYPE TYPE} node.
649     * @return true if current type is primitive type.
650     */
651    private static boolean isPrimitive(DetailAST type) {
652        return type.getFirstChild().getType() != TokenTypes.IDENT;
653    }
654
655    /**
656     * Gets canonical type's name from given {@link TokenTypes#TYPE TYPE} node.
657     *
658     * @param type DetailAST {@link TokenTypes#TYPE TYPE} node.
659     * @return canonical type's name
660     */
661    private static String getCanonicalName(DetailAST type) {
662        final StringBuilder canonicalNameBuilder = new StringBuilder(256);
663        DetailAST toVisit = type;
664        while (toVisit != null) {
665            toVisit = getNextSubTreeNode(toVisit, type);
666            if (toVisit != null && toVisit.getType() == TokenTypes.IDENT) {
667                if (!canonicalNameBuilder.isEmpty()) {
668                    canonicalNameBuilder.append('.');
669                }
670                canonicalNameBuilder.append(toVisit.getText());
671                final DetailAST nextSubTreeNode = getNextSubTreeNode(toVisit, type);
672                if (nextSubTreeNode != null
673                        && nextSubTreeNode.getType() == TokenTypes.TYPE_ARGUMENTS) {
674                    break;
675                }
676            }
677        }
678        return canonicalNameBuilder.toString();
679    }
680
681    /**
682     * Gets the next node of a syntactical tree (child of a current node or
683     * sibling of a current node, or sibling of a parent of a current node).
684     *
685     * @param currentNodeAst Current node in considering
686     * @param subTreeRootAst SubTree root
687     * @return Current node after bypassing, if current node reached the root of a subtree
688     *        method returns null
689     */
690    private static DetailAST
691        getNextSubTreeNode(DetailAST currentNodeAst, DetailAST subTreeRootAst) {
692        DetailAST currentNode = currentNodeAst;
693        DetailAST toVisitAst = currentNode.getFirstChild();
694        while (toVisitAst == null) {
695            toVisitAst = currentNode.getNextSibling();
696            if (currentNode.getParent().getColumnNo() == subTreeRootAst.getColumnNo()) {
697                break;
698            }
699            currentNode = currentNode.getParent();
700        }
701        return toVisitAst;
702    }
703
704    /**
705     * Converts canonical class names to short names.
706     *
707     * @param canonicalClassNames the set of canonical class names.
708     * @return the set of short names of classes.
709     */
710    private static Set<String> getClassShortNames(Set<String> canonicalClassNames) {
711        return canonicalClassNames.stream()
712            .map(CommonUtil::baseClassName)
713            .collect(Collectors.toCollection(HashSet::new));
714    }
715
716    /**
717     * Gets the short class name from given canonical name.
718     *
719     * @param canonicalClassName canonical class name.
720     * @return short name of class.
721     */
722    private static String getClassShortName(String canonicalClassName) {
723        return canonicalClassName
724                .substring(canonicalClassName.lastIndexOf('.') + 1);
725    }
726
727    /**
728     * Checks whether the AST is annotated with
729     * an annotation containing the passed in regular
730     * expression and return the AST representing that
731     * annotation.
732     *
733     * <p>
734     * This method will not look for imports or package
735     * statements to detect the passed in annotation.
736     * </p>
737     *
738     * <p>
739     * To check if an AST contains a passed in annotation
740     * taking into account fully-qualified names
741     * (ex: java.lang.Override, Override)
742     * this method will need to be called twice. Once for each
743     * name given.
744     * </p>
745     *
746     * @param variableDef {@link TokenTypes#VARIABLE_DEF variable def node}.
747     * @return the AST representing the first such annotation or null if
748     *         no such annotation was found
749     */
750    private DetailAST findMatchingAnnotation(DetailAST variableDef) {
751        DetailAST matchingAnnotation = null;
752
753        final DetailAST holder = AnnotationUtil.getAnnotationHolder(variableDef);
754
755        for (DetailAST child = holder.getFirstChild();
756            child != null; child = child.getNextSibling()) {
757            if (child.getType() == TokenTypes.ANNOTATION) {
758                final DetailAST ast = child.getFirstChild();
759                final String name =
760                    FullIdent.createFullIdent(ast.getNextSibling()).getText();
761                if (ignoreAnnotationCanonicalNames.contains(name)
762                         || ignoreAnnotationShortNames.contains(name)) {
763                    matchingAnnotation = child;
764                    break;
765                }
766            }
767        }
768
769        return matchingAnnotation;
770    }
771
772}