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 }