001/////////////////////////////////////////////////////////////////////////////////////////////// 002// checkstyle: Checks Java source code and other text files for adherence to a set of rules. 003// Copyright (C) 2001-2024 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.coding; 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; 026 027/** 028 * <p> 029 * Checks if unnecessary semicolon is in enum definitions. 030 * Semicolon is not needed if enum body contains only enum constants. 031 * </p> 032 * <p> 033 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker} 034 * </p> 035 * <p> 036 * Violation Message Keys: 037 * </p> 038 * <ul> 039 * <li> 040 * {@code unnecessary.semicolon} 041 * </li> 042 * </ul> 043 * 044 * @since 8.22 045 */ 046@StatelessCheck 047public final class UnnecessarySemicolonInEnumerationCheck extends AbstractCheck { 048 049 /** 050 * A key is pointing to the warning message text in "messages.properties" 051 * file. 052 */ 053 public static final String MSG_SEMI = "unnecessary.semicolon"; 054 055 @Override 056 public int[] getDefaultTokens() { 057 return getRequiredTokens(); 058 } 059 060 @Override 061 public int[] getAcceptableTokens() { 062 return getRequiredTokens(); 063 } 064 065 @Override 066 public int[] getRequiredTokens() { 067 return new int[] { 068 TokenTypes.ENUM_DEF, 069 }; 070 } 071 072 @Override 073 public void visitToken(DetailAST ast) { 074 final DetailAST enumBlock = ast.findFirstToken(TokenTypes.OBJBLOCK); 075 final DetailAST semicolon = enumBlock.findFirstToken(TokenTypes.SEMI); 076 if (semicolon != null && isEndOfEnumerationAfter(semicolon)) { 077 log(semicolon, MSG_SEMI); 078 } 079 } 080 081 /** 082 * Checks if enum body has no code elements after enum constants semicolon. 083 * 084 * @param ast semicolon in enum constants definition end 085 * @return true if there is no code elements, false otherwise. 086 */ 087 private static boolean isEndOfEnumerationAfter(DetailAST ast) { 088 return ast.getNextSibling().getType() == TokenTypes.RCURLY; 089 } 090}