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1   ///////////////////////////////////////////////////////////////////////////////////////////////
2   // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3   // Copyright (C) 2001-2026 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.whitespace;
21  
22  import com.puppycrawl.tools.checkstyle.StatelessCheck;
23  import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
24  import com.puppycrawl.tools.checkstyle.api.DetailAST;
25  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
26  import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
27  
28  /**
29   * <div>
30   * Checks that a token is followed by whitespace, with the exception that it
31   * does not check for whitespace after the semicolon of an empty for iterator.
32   * Use Check
33   * <a href="https://checkstyle.org/checks/whitespace/emptyforiteratorpad.html">
34   * EmptyForIteratorPad</a> to validate empty for iterators.
35   * </div>
36   *
37   * @since 3.0
38   */
39  @StatelessCheck
40  public class WhitespaceAfterCheck
41      extends AbstractCheck {
42  
43      /**
44       * A key is pointing to the warning message text in "messages.properties"
45       * file.
46       */
47      public static final String MSG_WS_NOT_FOLLOWED = "ws.notFollowed";
48  
49      /**
50       * A key is pointing to the warning message text in "messages.properties"
51       * file.
52       */
53      public static final String MSG_WS_TYPECAST = "ws.typeCast";
54  
55      /**
56       * Creates a new {@code WhitespaceAfterCheck} instance.
57       */
58      public WhitespaceAfterCheck() {
59          // no code by default
60      }
61  
62      @Override
63      public int[] getDefaultTokens() {
64          return new int[] {
65              TokenTypes.COMMA,
66              TokenTypes.SEMI,
67              TokenTypes.TYPECAST,
68              TokenTypes.LITERAL_IF,
69              TokenTypes.LITERAL_ELSE,
70              TokenTypes.LITERAL_WHILE,
71              TokenTypes.LITERAL_DO,
72              TokenTypes.LITERAL_FOR,
73              TokenTypes.LITERAL_FINALLY,
74              TokenTypes.LITERAL_RETURN,
75              TokenTypes.LITERAL_YIELD,
76              TokenTypes.LITERAL_CATCH,
77              TokenTypes.DO_WHILE,
78              TokenTypes.ELLIPSIS,
79              TokenTypes.LITERAL_SWITCH,
80              TokenTypes.LITERAL_SYNCHRONIZED,
81              TokenTypes.LITERAL_TRY,
82              TokenTypes.LITERAL_CASE,
83              TokenTypes.LAMBDA,
84              TokenTypes.LITERAL_WHEN,
85          };
86      }
87  
88      @Override
89      public int[] getAcceptableTokens() {
90          return new int[] {
91              TokenTypes.COMMA,
92              TokenTypes.SEMI,
93              TokenTypes.TYPECAST,
94              TokenTypes.LITERAL_IF,
95              TokenTypes.LITERAL_ELSE,
96              TokenTypes.LITERAL_WHILE,
97              TokenTypes.LITERAL_DO,
98              TokenTypes.LITERAL_FOR,
99              TokenTypes.LITERAL_FINALLY,
100             TokenTypes.LITERAL_RETURN,
101             TokenTypes.LITERAL_YIELD,
102             TokenTypes.LITERAL_CATCH,
103             TokenTypes.DO_WHILE,
104             TokenTypes.ELLIPSIS,
105             TokenTypes.LITERAL_SWITCH,
106             TokenTypes.LITERAL_SYNCHRONIZED,
107             TokenTypes.LITERAL_TRY,
108             TokenTypes.LITERAL_CASE,
109             TokenTypes.LAMBDA,
110             TokenTypes.LITERAL_WHEN,
111             TokenTypes.ANNOTATIONS,
112         };
113     }
114 
115     @Override
116     public int[] getRequiredTokens() {
117         return CommonUtil.EMPTY_INT_ARRAY;
118     }
119 
120     @Override
121     public void visitToken(DetailAST ast) {
122         if (ast.getType() == TokenTypes.TYPECAST) {
123             final DetailAST targetAST = ast.findFirstToken(TokenTypes.RPAREN);
124             final int[] line = getLineCodePoints(targetAST.getLineNo() - 1);
125             if (!isFollowedByWhitespace(targetAST, line)) {
126                 log(targetAST, MSG_WS_TYPECAST);
127             }
128         }
129         else if (ast.getType() == TokenTypes.ANNOTATIONS) {
130             if (ast.getFirstChild() != null) {
131                 DetailAST targetAST = ast.getFirstChild().getLastChild();
132                 if (targetAST.getType() == TokenTypes.DOT) {
133                     targetAST = targetAST.getLastChild();
134                 }
135                 final int[] line = getLineCodePoints(targetAST.getLineNo() - 1);
136                 if (!isFollowedByWhitespace(targetAST, line)) {
137                     final Object[] message = {targetAST.getText()};
138                     log(targetAST, MSG_WS_NOT_FOLLOWED, message);
139                 }
140             }
141         }
142         else {
143             final int[] line = getLineCodePoints(ast.getLineNo() - 1);
144             if (!isFollowedByWhitespace(ast, line)) {
145                 final Object[] message = {ast.getText()};
146                 log(ast, MSG_WS_NOT_FOLLOWED, message);
147             }
148         }
149     }
150 
151     /**
152      * Checks whether token is followed by a whitespace.
153      *
154      * @param targetAST Ast token.
155      * @param line Unicode code points array of line associated with the ast token.
156      * @return true if ast token is followed by a whitespace.
157      */
158     private static boolean isFollowedByWhitespace(DetailAST targetAST, int... line) {
159         final int after =
160             targetAST.getColumnNo() + targetAST.getText().length();
161         boolean followedByWhitespace = true;
162 
163         if (after < line.length) {
164             final int codePoint = line[after];
165 
166             followedByWhitespace = codePoint == ';'
167                 || codePoint == ')'
168                 || Character.isWhitespace(codePoint);
169         }
170         return followedByWhitespace;
171     }
172 
173 }