View Javadoc
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 com.puppycrawl.tools.checkstyle.StatelessCheck;
23  import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
24  import com.puppycrawl.tools.checkstyle.api.DetailAST;
25  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
26  import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
27  import com.puppycrawl.tools.checkstyle.utils.JavadocUtil;
28  import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
29  
30  /**
31   * <p>
32   * Checks for illegal tokens. By default, labels are prohibited.
33   * </p>
34   * <p>
35   * Rationale: Certain language features can harm readability, lead to
36   * confusion or are not obvious to novice developers. Other features
37   * may be discouraged in certain frameworks, such as not having
38   * native methods in Enterprise JavaBeans components.
39   * </p>
40   * <ul>
41   * <li>
42   * Property {@code tokens} - tokens to check
43   * Type is {@code anyTokenTypesSet}.
44   * Default value is
45   * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#LABELED_STAT">
46   * LABELED_STAT</a>.
47   * </li>
48   * </ul>
49   * <p>
50   * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
51   * </p>
52   * <p>
53   * Violation Message Keys:
54   * </p>
55   * <ul>
56   * <li>
57   * {@code illegal.token}
58   * </li>
59   * </ul>
60   *
61   * @since 3.2
62   */
63  @StatelessCheck
64  public class IllegalTokenCheck
65      extends AbstractCheck {
66  
67      /**
68       * A key is pointing to the warning message text in "messages.properties"
69       * file.
70       */
71      public static final String MSG_KEY = "illegal.token";
72  
73      @Override
74      public int[] getDefaultTokens() {
75          return new int[] {
76              TokenTypes.LABELED_STAT,
77          };
78      }
79  
80      @Override
81      public int[] getAcceptableTokens() {
82          return TokenUtil.getAllTokenIds();
83      }
84  
85      @Override
86      public int[] getRequiredTokens() {
87          return CommonUtil.EMPTY_INT_ARRAY;
88      }
89  
90      @Override
91      public boolean isCommentNodesRequired() {
92          return true;
93      }
94  
95      @Override
96      public void visitToken(DetailAST ast) {
97          log(
98              ast,
99              MSG_KEY,
100             convertToString(ast)
101         );
102     }
103 
104     /**
105      * Converts given AST node to string representation.
106      *
107      * @param ast node to be represented as string
108      * @return string representation of AST node
109      */
110     private static String convertToString(DetailAST ast) {
111         final String tokenText;
112         switch (ast.getType()) {
113             case TokenTypes.LABELED_STAT:
114                 tokenText = ast.getFirstChild().getText() + ast.getText();
115                 break;
116             // multiline tokens need to become singlelined
117             case TokenTypes.COMMENT_CONTENT:
118                 tokenText = JavadocUtil.escapeAllControlChars(ast.getText());
119                 break;
120             default:
121                 tokenText = ast.getText();
122                 break;
123         }
124         return tokenText;
125     }
126 
127 }