1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2024 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.coding;
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
27 /**
28 * <p>
29 * Checks if unnecessary semicolon is in enum definitions.
30 * Semicolon is not needed if enum body contains only enum constants.
31 * </p>
32 * <p>
33 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
34 * </p>
35 * <p>
36 * Violation Message Keys:
37 * </p>
38 * <ul>
39 * <li>
40 * {@code unnecessary.semicolon}
41 * </li>
42 * </ul>
43 *
44 * @since 8.22
45 */
46 @StatelessCheck
47 public final class UnnecessarySemicolonInEnumerationCheck extends AbstractCheck {
48
49 /**
50 * A key is pointing to the warning message text in "messages.properties"
51 * file.
52 */
53 public static final String MSG_SEMI = "unnecessary.semicolon";
54
55 @Override
56 public int[] getDefaultTokens() {
57 return getRequiredTokens();
58 }
59
60 @Override
61 public int[] getAcceptableTokens() {
62 return getRequiredTokens();
63 }
64
65 @Override
66 public int[] getRequiredTokens() {
67 return new int[] {
68 TokenTypes.ENUM_DEF,
69 };
70 }
71
72 @Override
73 public void visitToken(DetailAST ast) {
74 final DetailAST enumBlock = ast.findFirstToken(TokenTypes.OBJBLOCK);
75 final DetailAST semicolon = enumBlock.findFirstToken(TokenTypes.SEMI);
76 if (semicolon != null && isEndOfEnumerationAfter(semicolon)) {
77 log(semicolon, MSG_SEMI);
78 }
79 }
80
81 /**
82 * Checks if enum body has no code elements after enum constants semicolon.
83 *
84 * @param ast semicolon in enum constants definition end
85 * @return true if there is no code elements, false otherwise.
86 */
87 private static boolean isEndOfEnumerationAfter(DetailAST ast) {
88 return ast.getNextSibling().getType() == TokenTypes.RCURLY;
89 }
90 }