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.FileStatefulCheck; 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 the number of types declared at the <i>outer</i> (or <i>root</i>) level in a file. 030 * </p> 031 * <p> 032 * Rationale: It is considered good practice to only define one outer type per file. 033 * </p> 034 * <ul> 035 * <li> 036 * Property {@code max} - Specify the maximum number of outer types allowed. 037 * Type is {@code int}. 038 * Default value is {@code 1}. 039 * </li> 040 * </ul> 041 * <p> 042 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker} 043 * </p> 044 * <p> 045 * Violation Message Keys: 046 * </p> 047 * <ul> 048 * <li> 049 * {@code maxOuterTypes} 050 * </li> 051 * </ul> 052 * 053 * @since 5.0 054 */ 055@FileStatefulCheck 056public class OuterTypeNumberCheck extends AbstractCheck { 057 058 /** 059 * A key is pointing to the warning message text in "messages.properties" 060 * file. 061 */ 062 public static final String MSG_KEY = "maxOuterTypes"; 063 064 /** Specify the maximum number of outer types allowed. */ 065 private int max = 1; 066 /** Tracks the current depth in types. */ 067 private int currentDepth; 068 /** Tracks the number of outer types found. */ 069 private int outerNum; 070 071 @Override 072 public int[] getDefaultTokens() { 073 return getRequiredTokens(); 074 } 075 076 @Override 077 public int[] getAcceptableTokens() { 078 return getRequiredTokens(); 079 } 080 081 @Override 082 public int[] getRequiredTokens() { 083 return new int[] { 084 TokenTypes.CLASS_DEF, 085 TokenTypes.INTERFACE_DEF, 086 TokenTypes.ENUM_DEF, 087 TokenTypes.ANNOTATION_DEF, 088 TokenTypes.RECORD_DEF, 089 }; 090 } 091 092 @Override 093 public void beginTree(DetailAST ast) { 094 currentDepth = 0; 095 outerNum = 0; 096 } 097 098 @Override 099 public void finishTree(DetailAST ast) { 100 if (max < outerNum) { 101 log(ast, MSG_KEY, outerNum, max); 102 } 103 } 104 105 @Override 106 public void visitToken(DetailAST ast) { 107 if (currentDepth == 0) { 108 outerNum++; 109 } 110 currentDepth++; 111 } 112 113 @Override 114 public void leaveToken(DetailAST ast) { 115 currentDepth--; 116 } 117 118 /** 119 * Setter to specify the maximum number of outer types allowed. 120 * 121 * @param max the new number. 122 * @since 5.0 123 */ 124 public void setMax(int max) { 125 this.max = max; 126 } 127 128}