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.sizes; 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 for long anonymous inner classes. 030 * </p> 031 * <p> 032 * Rationale: If an anonymous inner class becomes very long 033 * it is hard to understand and to see the flow of the method 034 * where the class is defined. Therefore, long anonymous inner 035 * classes should usually be refactored into a named inner class. 036 * See also Bloch, Effective Java, p. 93. 037 * </p> 038 * <ul> 039 * <li> 040 * Property {@code max} - Specify the maximum number of lines allowed. 041 * Type is {@code int}. 042 * Default value is {@code 20}. 043 * </li> 044 * </ul> 045 * <p> 046 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker} 047 * </p> 048 * <p> 049 * Violation Message Keys: 050 * </p> 051 * <ul> 052 * <li> 053 * {@code maxLen.anonInner} 054 * </li> 055 * </ul> 056 * 057 * @since 3.2 058 */ 059@StatelessCheck 060public class AnonInnerLengthCheck extends AbstractCheck { 061 062 /** 063 * A key is pointing to the warning message text in "messages.properties" 064 * file. 065 */ 066 public static final String MSG_KEY = "maxLen.anonInner"; 067 068 /** Default maximum number of lines. */ 069 private static final int DEFAULT_MAX = 20; 070 071 /** Specify the maximum number of lines allowed. */ 072 private int max = DEFAULT_MAX; 073 074 @Override 075 public int[] getDefaultTokens() { 076 return getRequiredTokens(); 077 } 078 079 @Override 080 public int[] getAcceptableTokens() { 081 return getRequiredTokens(); 082 } 083 084 @Override 085 public int[] getRequiredTokens() { 086 return new int[] {TokenTypes.LITERAL_NEW}; 087 } 088 089 @Override 090 public void visitToken(DetailAST ast) { 091 final DetailAST openingBrace = ast.findFirstToken(TokenTypes.OBJBLOCK); 092 if (openingBrace != null) { 093 final DetailAST closingBrace = 094 openingBrace.findFirstToken(TokenTypes.RCURLY); 095 final int length = 096 closingBrace.getLineNo() - openingBrace.getLineNo() + 1; 097 if (length > max) { 098 log(ast, MSG_KEY, length, max); 099 } 100 } 101 } 102 103 /** 104 * Setter to specify the maximum number of lines allowed. 105 * 106 * @param length the maximum length of an anonymous inner class. 107 * @since 3.2 108 */ 109 public void setMax(int length) { 110 max = length; 111 } 112 113}