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 java.io.File; 023 024import com.puppycrawl.tools.checkstyle.FileStatefulCheck; 025import com.puppycrawl.tools.checkstyle.api.AbstractCheck; 026import com.puppycrawl.tools.checkstyle.api.DetailAST; 027import com.puppycrawl.tools.checkstyle.api.FullIdent; 028import com.puppycrawl.tools.checkstyle.api.TokenTypes; 029 030/** 031 * <p> 032 * Ensures that a class has a package declaration, and (optionally) whether 033 * the package name matches the directory name for the source file. 034 * </p> 035 * <p> 036 * Rationale: Classes that live in the null package cannot be imported. 037 * Many novice developers are not aware of this. 038 * </p> 039 * <p> 040 * Packages provide logical namespace to classes and should be stored in 041 * the form of directory levels to provide physical grouping to your classes. 042 * These directories are added to the classpath so that your classes 043 * are visible to JVM when it runs the code. 044 * </p> 045 * <ul> 046 * <li> 047 * Property {@code matchDirectoryStructure} - Control whether to check for 048 * directory and package name match. 049 * Type is {@code boolean}. 050 * Default value is {@code true}. 051 * </li> 052 * </ul> 053 * <p> 054 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker} 055 * </p> 056 * <p> 057 * Violation Message Keys: 058 * </p> 059 * <ul> 060 * <li> 061 * {@code mismatch.package.directory} 062 * </li> 063 * <li> 064 * {@code missing.package.declaration} 065 * </li> 066 * </ul> 067 * 068 * @since 3.2 069 */ 070@FileStatefulCheck 071public final class PackageDeclarationCheck extends AbstractCheck { 072 073 /** 074 * A key is pointing to the warning message text in "messages.properties" 075 * file. 076 */ 077 public static final String MSG_KEY_MISSING = "missing.package.declaration"; 078 079 /** 080 * A key is pointing to the warning message text in "messages.properties" 081 * file. 082 */ 083 public static final String MSG_KEY_MISMATCH = "mismatch.package.directory"; 084 085 /** Is package defined. */ 086 private boolean defined; 087 088 /** Control whether to check for directory and package name match. */ 089 private boolean matchDirectoryStructure = true; 090 091 /** 092 * Setter to control whether to check for directory and package name match. 093 * 094 * @param matchDirectoryStructure the new value. 095 * @since 7.6.1 096 */ 097 public void setMatchDirectoryStructure(boolean matchDirectoryStructure) { 098 this.matchDirectoryStructure = matchDirectoryStructure; 099 } 100 101 @Override 102 public int[] getDefaultTokens() { 103 return getRequiredTokens(); 104 } 105 106 @Override 107 public int[] getRequiredTokens() { 108 return new int[] {TokenTypes.PACKAGE_DEF}; 109 } 110 111 @Override 112 public int[] getAcceptableTokens() { 113 return getRequiredTokens(); 114 } 115 116 @Override 117 public void beginTree(DetailAST ast) { 118 defined = false; 119 } 120 121 @Override 122 public void finishTree(DetailAST ast) { 123 if (!defined && ast != null) { 124 log(ast, MSG_KEY_MISSING); 125 } 126 } 127 128 @Override 129 public void visitToken(DetailAST ast) { 130 defined = true; 131 132 if (matchDirectoryStructure) { 133 final DetailAST packageNameAst = ast.getLastChild().getPreviousSibling(); 134 final FullIdent fullIdent = FullIdent.createFullIdent(packageNameAst); 135 final String packageName = fullIdent.getText().replace('.', File.separatorChar); 136 137 final String directoryName = getDirectoryName(); 138 139 if (!directoryName.endsWith(packageName)) { 140 log(ast, MSG_KEY_MISMATCH, packageName); 141 } 142 } 143 } 144 145 /** 146 * Returns the directory name this file is in. 147 * 148 * @return Directory name. 149 */ 150 private String getDirectoryName() { 151 final String fileName = getFilePath(); 152 final int lastSeparatorPos = fileName.lastIndexOf(File.separatorChar); 153 return fileName.substring(0, lastSeparatorPos); 154 } 155 156}