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.whitespace;
021
022import com.puppycrawl.tools.checkstyle.StatelessCheck;
023import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
024import com.puppycrawl.tools.checkstyle.api.DetailAST;
025import com.puppycrawl.tools.checkstyle.api.TokenTypes;
026import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
027
028/**
029 * <div>
030 * Checks that a token is followed by whitespace, with the exception that it
031 * does not check for whitespace after the semicolon of an empty for iterator.
032 * Use Check
033 * <a href="https://checkstyle.org/checks/whitespace/emptyforiteratorpad.html">
034 * EmptyForIteratorPad</a> to validate empty for iterators.
035 * </div>
036 *
037 * @since 3.0
038 */
039@StatelessCheck
040public class WhitespaceAfterCheck
041    extends AbstractCheck {
042
043    /**
044     * A key is pointing to the warning message text in "messages.properties"
045     * file.
046     */
047    public static final String MSG_WS_NOT_FOLLOWED = "ws.notFollowed";
048
049    /**
050     * A key is pointing to the warning message text in "messages.properties"
051     * file.
052     */
053    public static final String MSG_WS_TYPECAST = "ws.typeCast";
054
055    @Override
056    public int[] getDefaultTokens() {
057        return new int[] {
058            TokenTypes.COMMA,
059            TokenTypes.SEMI,
060            TokenTypes.TYPECAST,
061            TokenTypes.LITERAL_IF,
062            TokenTypes.LITERAL_ELSE,
063            TokenTypes.LITERAL_WHILE,
064            TokenTypes.LITERAL_DO,
065            TokenTypes.LITERAL_FOR,
066            TokenTypes.LITERAL_FINALLY,
067            TokenTypes.LITERAL_RETURN,
068            TokenTypes.LITERAL_YIELD,
069            TokenTypes.LITERAL_CATCH,
070            TokenTypes.DO_WHILE,
071            TokenTypes.ELLIPSIS,
072            TokenTypes.LITERAL_SWITCH,
073            TokenTypes.LITERAL_SYNCHRONIZED,
074            TokenTypes.LITERAL_TRY,
075            TokenTypes.LITERAL_CASE,
076            TokenTypes.LAMBDA,
077            TokenTypes.LITERAL_WHEN,
078        };
079    }
080
081    @Override
082    public int[] getAcceptableTokens() {
083        return new int[] {
084            TokenTypes.COMMA,
085            TokenTypes.SEMI,
086            TokenTypes.TYPECAST,
087            TokenTypes.LITERAL_IF,
088            TokenTypes.LITERAL_ELSE,
089            TokenTypes.LITERAL_WHILE,
090            TokenTypes.LITERAL_DO,
091            TokenTypes.LITERAL_FOR,
092            TokenTypes.LITERAL_FINALLY,
093            TokenTypes.LITERAL_RETURN,
094            TokenTypes.LITERAL_YIELD,
095            TokenTypes.LITERAL_CATCH,
096            TokenTypes.DO_WHILE,
097            TokenTypes.ELLIPSIS,
098            TokenTypes.LITERAL_SWITCH,
099            TokenTypes.LITERAL_SYNCHRONIZED,
100            TokenTypes.LITERAL_TRY,
101            TokenTypes.LITERAL_CASE,
102            TokenTypes.LAMBDA,
103            TokenTypes.LITERAL_WHEN,
104            TokenTypes.ANNOTATIONS,
105        };
106    }
107
108    @Override
109    public int[] getRequiredTokens() {
110        return CommonUtil.EMPTY_INT_ARRAY;
111    }
112
113    @Override
114    public void visitToken(DetailAST ast) {
115        if (ast.getType() == TokenTypes.TYPECAST) {
116            final DetailAST targetAST = ast.findFirstToken(TokenTypes.RPAREN);
117            final int[] line = getLineCodePoints(targetAST.getLineNo() - 1);
118            if (!isFollowedByWhitespace(targetAST, line)) {
119                log(targetAST, MSG_WS_TYPECAST);
120            }
121        }
122        else if (ast.getType() == TokenTypes.ANNOTATIONS) {
123            if (ast.getFirstChild() != null) {
124                DetailAST targetAST = ast.getFirstChild().getLastChild();
125                if (targetAST.getType() == TokenTypes.DOT) {
126                    targetAST = targetAST.getLastChild();
127                }
128                final int[] line = getLineCodePoints(targetAST.getLineNo() - 1);
129                if (!isFollowedByWhitespace(targetAST, line)) {
130                    final Object[] message = {targetAST.getText()};
131                    log(targetAST, MSG_WS_NOT_FOLLOWED, message);
132                }
133            }
134        }
135        else {
136            final int[] line = getLineCodePoints(ast.getLineNo() - 1);
137            if (!isFollowedByWhitespace(ast, line)) {
138                final Object[] message = {ast.getText()};
139                log(ast, MSG_WS_NOT_FOLLOWED, message);
140            }
141        }
142    }
143
144    /**
145     * Checks whether token is followed by a whitespace.
146     *
147     * @param targetAST Ast token.
148     * @param line Unicode code points array of line associated with the ast token.
149     * @return true if ast token is followed by a whitespace.
150     */
151    private static boolean isFollowedByWhitespace(DetailAST targetAST, int... line) {
152        final int after =
153            targetAST.getColumnNo() + targetAST.getText().length();
154        boolean followedByWhitespace = true;
155
156        if (after < line.length) {
157            final int codePoint = line[after];
158
159            followedByWhitespace = codePoint == ';'
160                || codePoint == ')'
161                || Character.isWhitespace(codePoint);
162        }
163        return followedByWhitespace;
164    }
165
166}