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 * <div> 029 * Checks if unnecessary semicolon is in enum definitions. 030 * Semicolon is not needed if enum body contains only enum constants. 031 * </div> 032 * 033 * <p> 034 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker} 035 * </p> 036 * 037 * <p> 038 * Violation Message Keys: 039 * </p> 040 * <ul> 041 * <li> 042 * {@code unnecessary.semicolon} 043 * </li> 044 * </ul> 045 * 046 * @since 8.22 047 */ 048@StatelessCheck 049public final class UnnecessarySemicolonInEnumerationCheck extends AbstractCheck { 050 051 /** 052 * A key is pointing to the warning message text in "messages.properties" 053 * file. 054 */ 055 public static final String MSG_SEMI = "unnecessary.semicolon"; 056 057 @Override 058 public int[] getDefaultTokens() { 059 return getRequiredTokens(); 060 } 061 062 @Override 063 public int[] getAcceptableTokens() { 064 return getRequiredTokens(); 065 } 066 067 @Override 068 public int[] getRequiredTokens() { 069 return new int[] { 070 TokenTypes.ENUM_DEF, 071 }; 072 } 073 074 @Override 075 public void visitToken(DetailAST ast) { 076 final DetailAST enumBlock = ast.findFirstToken(TokenTypes.OBJBLOCK); 077 final DetailAST semicolon = enumBlock.findFirstToken(TokenTypes.SEMI); 078 if (semicolon != null && isEndOfEnumerationAfter(semicolon)) { 079 log(semicolon, MSG_SEMI); 080 } 081 } 082 083 /** 084 * Checks if enum body has no code elements after enum constants semicolon. 085 * 086 * @param ast semicolon in enum constants definition end 087 * @return true if there is no code elements, false otherwise. 088 */ 089 private static boolean isEndOfEnumerationAfter(DetailAST ast) { 090 return ast.getNextSibling().getType() == TokenTypes.RCURLY; 091 } 092}