1 /////////////////////////////////////////////////////////////////////////////////////////////// 2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules. 3 // Copyright (C) 2001-2024 the original author or authors. 4 // 5 // This library is free software; you can redistribute it and/or 6 // modify it under the terms of the GNU Lesser General Public 7 // License as published by the Free Software Foundation; either 8 // version 2.1 of the License, or (at your option) any later version. 9 // 10 // This library is distributed in the hope that it will be useful, 11 // but WITHOUT ANY WARRANTY; without even the implied warranty of 12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 // Lesser General Public License for more details. 14 // 15 // You should have received a copy of the GNU Lesser General Public 16 // License along with this library; if not, write to the Free Software 17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 /////////////////////////////////////////////////////////////////////////////////////////////// 19 20 package com.puppycrawl.tools.checkstyle.checks.coding; 21 22 import java.io.File; 23 24 import com.puppycrawl.tools.checkstyle.FileStatefulCheck; 25 import com.puppycrawl.tools.checkstyle.api.AbstractCheck; 26 import com.puppycrawl.tools.checkstyle.api.DetailAST; 27 import com.puppycrawl.tools.checkstyle.api.FullIdent; 28 import com.puppycrawl.tools.checkstyle.api.TokenTypes; 29 30 /** 31 * <p> 32 * Ensures that a class has a package declaration, and (optionally) whether 33 * the package name matches the directory name for the source file. 34 * </p> 35 * <p> 36 * Rationale: Classes that live in the null package cannot be imported. 37 * Many novice developers are not aware of this. 38 * </p> 39 * <p> 40 * Packages provide logical namespace to classes and should be stored in 41 * the form of directory levels to provide physical grouping to your classes. 42 * These directories are added to the classpath so that your classes 43 * are visible to JVM when it runs the code. 44 * </p> 45 * <ul> 46 * <li> 47 * Property {@code matchDirectoryStructure} - Control whether to check for 48 * directory and package name match. 49 * Type is {@code boolean}. 50 * Default value is {@code true}. 51 * </li> 52 * </ul> 53 * <p> 54 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker} 55 * </p> 56 * <p> 57 * Violation Message Keys: 58 * </p> 59 * <ul> 60 * <li> 61 * {@code mismatch.package.directory} 62 * </li> 63 * <li> 64 * {@code missing.package.declaration} 65 * </li> 66 * </ul> 67 * 68 * @since 3.2 69 */ 70 @FileStatefulCheck 71 public final class PackageDeclarationCheck extends AbstractCheck { 72 73 /** 74 * A key is pointing to the warning message text in "messages.properties" 75 * file. 76 */ 77 public static final String MSG_KEY_MISSING = "missing.package.declaration"; 78 79 /** 80 * A key is pointing to the warning message text in "messages.properties" 81 * file. 82 */ 83 public static final String MSG_KEY_MISMATCH = "mismatch.package.directory"; 84 85 /** Is package defined. */ 86 private boolean defined; 87 88 /** Control whether to check for directory and package name match. */ 89 private boolean matchDirectoryStructure = true; 90 91 /** 92 * Setter to control whether to check for directory and package name match. 93 * 94 * @param matchDirectoryStructure the new value. 95 * @since 7.6.1 96 */ 97 public void setMatchDirectoryStructure(boolean matchDirectoryStructure) { 98 this.matchDirectoryStructure = matchDirectoryStructure; 99 } 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 }