JavadocVariableCheck.java
///////////////////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
// Copyright (C) 2001-2025 the original author or authors.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
///////////////////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle.checks.javadoc;
import java.util.Arrays;
import java.util.regex.Pattern;
import com.puppycrawl.tools.checkstyle.StatelessCheck;
import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.FileContents;
import com.puppycrawl.tools.checkstyle.api.TextBlock;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import com.puppycrawl.tools.checkstyle.checks.naming.AccessModifierOption;
import com.puppycrawl.tools.checkstyle.utils.CheckUtil;
import com.puppycrawl.tools.checkstyle.utils.ScopeUtil;
import com.puppycrawl.tools.checkstyle.utils.UnmodifiableCollectionUtil;
/**
* <div>
* Checks that a variable has a Javadoc comment. Ignores {@code serialVersionUID} fields.
* </div>
* <ul>
* <li>
* Property {@code accessModifiers} - Specify the set of access modifiers used to determine which
* fields should be checked. This includes both explicitly declared modifiers and implicit ones,
* such as package-private for fields without an explicit modifier.
* It also accounts for special cases where fields have implicit modifiers,
* such as {@code public static final} for interface fields and {@code public static}
* for enum constants, or where the nesting types accessibility is more restrictive and hides the
* nested field. Only fields matching the specified modifiers will be analyzed.
* Type is {@code com.puppycrawl.tools.checkstyle.checks.naming.AccessModifierOption[]}.
* Default value is {@code public, protected, package, private}.
* </li>
* <li>
* Property {@code ignoreNamePattern} - Specify the regexp to define variable names to ignore.
* Type is {@code java.util.regex.Pattern}.
* Default value is {@code null}.
* </li>
* <li>
* Property {@code tokens} - tokens to check
* Type is {@code java.lang.String[]}.
* Validation type is {@code tokenSet}.
* Default value is:
* <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#ENUM_CONSTANT_DEF">
* ENUM_CONSTANT_DEF</a>.
* </li>
* </ul>
*
* <p>
* Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
* </p>
*
* <p>
* Violation Message Keys:
* </p>
* <ul>
* <li>
* {@code javadoc.missing}
* </li>
* </ul>
*
* @since 3.0
*/
@StatelessCheck
public class JavadocVariableCheck
extends AbstractCheck {
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_JAVADOC_MISSING = "javadoc.missing";
/**
* Specify the set of access modifiers used to determine which fields should be checked.
* This includes both explicitly declared modifiers and implicit ones, such as package-private
* for fields without an explicit modifier. It also accounts for special cases where fields
* have implicit modifiers, such as {@code public static final} for interface fields and
* {@code public static} for enum constants, or where the nesting types accessibility is more
* restrictive and hides the nested field.
* Only fields matching the specified modifiers will be analyzed.
*/
private AccessModifierOption[] accessModifiers = {
AccessModifierOption.PUBLIC,
AccessModifierOption.PROTECTED,
AccessModifierOption.PACKAGE,
AccessModifierOption.PRIVATE,
};
/** Specify the regexp to define variable names to ignore. */
private Pattern ignoreNamePattern;
/**
* Setter to specify the set of access modifiers used to determine which fields should be
* checked. This includes both explicitly declared modifiers and implicit ones, such as
* package-private for fields without an explicit modifier. It also accounts for special
* cases where fields have implicit modifiers, such as {@code public static final}
* for interface fields and {@code public static} for enum constants, or where the nesting
* types accessibility is more restrictive and hides the nested field.
* Only fields matching the specified modifiers will be analyzed.
*
* @param accessModifiers access modifiers of fields to check.
* @since 10.22.0
*/
public void setAccessModifiers(AccessModifierOption... accessModifiers) {
this.accessModifiers =
UnmodifiableCollectionUtil.copyOfArray(accessModifiers, accessModifiers.length);
}
/**
* Setter to specify the regexp to define variable names to ignore.
*
* @param pattern a pattern.
* @since 5.8
*/
public void setIgnoreNamePattern(Pattern pattern) {
ignoreNamePattern = pattern;
}
@Override
public int[] getDefaultTokens() {
return getAcceptableTokens();
}
@Override
public int[] getAcceptableTokens() {
return new int[] {
TokenTypes.VARIABLE_DEF,
TokenTypes.ENUM_CONSTANT_DEF,
};
}
/*
* Skipping enum values is requested.
* Checkstyle's issue #1669: https://github.com/checkstyle/checkstyle/issues/1669
*/
@Override
public int[] getRequiredTokens() {
return new int[] {
TokenTypes.VARIABLE_DEF,
};
}
// suppress deprecation until https://github.com/checkstyle/checkstyle/issues/11166
@SuppressWarnings("deprecation")
@Override
public void visitToken(DetailAST ast) {
if (shouldCheck(ast)) {
final FileContents contents = getFileContents();
final TextBlock textBlock =
contents.getJavadocBefore(ast.getLineNo());
if (textBlock == null) {
log(ast, MSG_JAVADOC_MISSING);
}
}
}
/**
* Decides whether the variable name of an AST is in the ignore list.
*
* @param ast the AST to check
* @return true if the variable name of ast is in the ignore list.
*/
private boolean isIgnored(DetailAST ast) {
final String name = ast.findFirstToken(TokenTypes.IDENT).getText();
return ignoreNamePattern != null && ignoreNamePattern.matcher(name).matches()
|| "serialVersionUID".equals(name);
}
/**
* Checks whether a method has the correct access modifier to be checked.
*
* @param accessModifier the access modifier of the method.
* @return whether the method matches the expected access modifier.
*/
private boolean matchAccessModifiers(AccessModifierOption accessModifier) {
return Arrays.stream(accessModifiers)
.anyMatch(modifier -> modifier == accessModifier);
}
/**
* Whether we should check this node.
*
* @param ast a given node.
* @return whether we should check a given node.
*/
private boolean shouldCheck(final DetailAST ast) {
boolean result = false;
if (!ScopeUtil.isInCodeBlock(ast) && !isIgnored(ast)) {
final AccessModifierOption accessModifier =
getAccessModifierFromModifiersTokenWithPrivateEnumSupport(ast);
result = matchAccessModifiers(accessModifier);
}
return result;
}
/**
* A derivative of {@link CheckUtil#getAccessModifierFromModifiersToken(DetailAST)} that
* considers enum definitions' visibility when evaluating the accessibility of an enum
* constant.
* <br>
* <a href="https://github.com/checkstyle/checkstyle/pull/16787/files#r2073671898">Implemented
* separately</a> to reduce scope of fix for
* <a href="https://github.com/checkstyle/checkstyle/issues/16786">issue #16786</a> until a
* wider solution can be developed.
*
* @param ast the token of the method/constructor.
* @return the access modifier of the method/constructor.
*/
public static AccessModifierOption getAccessModifierFromModifiersTokenWithPrivateEnumSupport(
DetailAST ast) {
// In some scenarios we want to investigate a parent AST instead
DetailAST selectedAst = ast;
if (selectedAst.getType() == TokenTypes.ENUM_CONSTANT_DEF) {
// Enum constants don't have modifiers
// implicitly public but validate against parent(s)
while (selectedAst.getType() != TokenTypes.ENUM_DEF) {
selectedAst = selectedAst.getParent();
}
}
return CheckUtil.getAccessModifierFromModifiersToken(selectedAst);
}
}