001//////////////////////////////////////////////////////////////////////////////// 002// checkstyle: Checks Java source code for adherence to a set of rules. 003// Copyright (C) 2001-2014 Oliver Burn 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//////////////////////////////////////////////////////////////////////////////// 019package com.puppycrawl.tools.checkstyle.checks.design; 020 021import java.util.Map; 022import java.util.TreeMap; 023 024import com.puppycrawl.tools.checkstyle.api.Check; 025import com.puppycrawl.tools.checkstyle.api.DetailAST; 026import com.puppycrawl.tools.checkstyle.api.TokenTypes; 027 028/** 029 * 030 * Checks that each top-level class, interface 031 * or enum resides in a source file of its own. 032 * <p> 033 * Official description of a 'top-level' term:<a 034 * href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-7.html#jls-7.6"> 035 * 7.6. Top Level Type Declarations</a>. If file doesn't contains 036 * public class, enum or interface, top-level type is the first type in file. 037 * </p> 038 * <p> 039 * An example of code with violations: 040 * </p> 041 * <pre><code> 042 * public class Foo{ 043 * //methods 044 * } 045 * 046 * class Foo2{ 047 * //methods 048 * } 049 * </code></pre> 050 * <p> 051 * An example of code without top-level public type: 052 * </p> 053 * <pre><code> 054 * class Foo{ //top-level class 055 * //methods 056 * } 057 * 058 * class Foo2{ 059 * //methods 060 * } 061 * </code></pre> 062 * <p> 063 * An example of check's configuration: 064 * </p> 065 * <pre> 066 * <module name="OneTopLevelClass"/> 067 * </pre> 068 * 069 * <p> 070 * An example of code without violations: 071 * </p> 072 * <pre><code> 073 * public class Foo{ 074 * //methods 075 * } 076 * </code></pre> 077 * 078 * @author maxvetrenko 079 */ 080public class OneTopLevelClassCheck extends Check 081{ 082 083 /** 084 * True if a java source file contains a type 085 * with a public access level modifier. 086 */ 087 private boolean publicTypeFound; 088 089 /** Mapping between type names and line numbers of the type declarations.*/ 090 private TreeMap<Integer, String> lineNumberTypeMap = 091 new TreeMap<Integer, String>(); 092 093 @Override 094 public int[] getDefaultTokens() 095 { 096 return new int[] {}; 097 } 098 099 @Override 100 public void beginTree(DetailAST rootAST) 101 { 102 DetailAST currentNode = rootAST; 103 while (currentNode != null) { 104 if (currentNode.getType() == TokenTypes.CLASS_DEF 105 || currentNode.getType() == TokenTypes.ENUM_DEF 106 || currentNode.getType() == TokenTypes.INTERFACE_DEF) 107 { 108 if (isPublic(currentNode)) { 109 publicTypeFound = true; 110 } 111 112 else { 113 final String typeName = currentNode. 114 findFirstToken(TokenTypes.IDENT).getText(); 115 lineNumberTypeMap.put(currentNode.getLineNo(), typeName); 116 } 117 } 118 currentNode = currentNode.getNextSibling(); 119 } 120 } 121 122 @Override 123 public void finishTree(DetailAST rootAST) 124 { 125 if (!publicTypeFound && !lineNumberTypeMap.isEmpty()) { 126 // skip first top-level type. 127 lineNumberTypeMap.remove(lineNumberTypeMap.firstKey()); 128 } 129 130 for (Map.Entry<Integer, String> entry 131 : lineNumberTypeMap.entrySet()) 132 { 133 log(entry.getKey(), "one.top.level.class", entry.getValue()); 134 } 135 136 lineNumberTypeMap.clear(); 137 publicTypeFound = false; 138 } 139 140 /** 141 * Checks if a type is public. 142 * @param typeDef type definition node. 143 * @return true if a type has a public access level modifier. 144 */ 145 private boolean isPublic(DetailAST typeDef) 146 { 147 final DetailAST modifiers = 148 typeDef.findFirstToken(TokenTypes.MODIFIERS); 149 return modifiers.findFirstToken(TokenTypes.LITERAL_PUBLIC) != null; 150 } 151}