View Javadoc
1   ////////////////////////////////////////////////////////////////////////////////
2   // checkstyle: Checks Java source code for adherence to a set of rules.
3   // Copyright (C) 2001-2017 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   * Ensures there is a package declaration.
32   * Optionally checks if directory structure matches package name.
33   * Rationale: Classes that live in the null package cannot be
34   * imported. Many novice developers are not aware of this.
35   * Packages provide logical namespace to classes and should be stored in
36   * the form of directory levels to provide physical grouping to your classes.
37   * These directories are added to the classpath so that your classes
38   * are visible to JVM when it runs the code.
39   *
40   * @author <a href="mailto:simon@redhillconsulting.com.au">Simon Harris</a>
41   * @author Oliver Burn
42   * @author Vikramaditya Kukreja
43   */
44  @FileStatefulCheck
45  public final class PackageDeclarationCheck extends AbstractCheck {
46  
47      /**
48       * A key is pointing to the warning message text in "messages.properties"
49       * file.
50       */
51      public static final String MSG_KEY_MISSING = "missing.package.declaration";
52  
53      /**
54       * A key is pointing to the warning message text in "messages.properties"
55       * file.
56       */
57      public static final String MSG_KEY_MISMATCH = "mismatch.package.directory";
58  
59      /** Line number used to log violation when no AST nodes are present in file. */
60      private static final int DEFAULT_LINE_NUMBER = 1;
61  
62      /** Is package defined. */
63      private boolean defined;
64  
65      /** Whether to check for directory and package name match. */
66      private boolean matchDirectoryStructure = true;
67  
68      /**
69       * Set whether to check for directory and package name match.
70       * @param matchDirectoryStructure the new value.
71       */
72      public void setMatchDirectoryStructure(boolean matchDirectoryStructure) {
73          this.matchDirectoryStructure = matchDirectoryStructure;
74      }
75  
76      @Override
77      public int[] getDefaultTokens() {
78          return getRequiredTokens();
79      }
80  
81      @Override
82      public int[] getRequiredTokens() {
83          return new int[] {TokenTypes.PACKAGE_DEF};
84      }
85  
86      @Override
87      public int[] getAcceptableTokens() {
88          return getRequiredTokens();
89      }
90  
91      @Override
92      public void beginTree(DetailAST ast) {
93          defined = false;
94      }
95  
96      @Override
97      public void finishTree(DetailAST ast) {
98          if (!defined) {
99              int lineNumber = DEFAULT_LINE_NUMBER;
100             if (ast != null) {
101                 lineNumber = ast.getLineNo();
102             }
103             log(lineNumber, MSG_KEY_MISSING);
104         }
105     }
106 
107     @Override
108     public void visitToken(DetailAST ast) {
109         defined = true;
110 
111         if (matchDirectoryStructure) {
112 
113             final DetailAST packageNameAst = ast.getLastChild().getPreviousSibling();
114             final FullIdent fullIdent = FullIdent.createFullIdent(packageNameAst);
115             final String packageName = fullIdent.getText().replace('.', File.separatorChar);
116 
117             final String directoryName = getDirectoryName();
118 
119             if (!directoryName.endsWith(packageName)) {
120                 log(fullIdent.getLineNo(), MSG_KEY_MISMATCH, packageName);
121             }
122         }
123     }
124 
125     /**
126      * Returns the directory name this file is in.
127      * @return Directory name.
128      */
129     private String getDirectoryName() {
130         final String fileName = getFileContents().getFileName();
131         final int lastSeparatorPos = fileName.lastIndexOf(File.separatorChar);
132         return fileName.substring(0, lastSeparatorPos);
133     }
134 }