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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  
27  /**
28   * <div>
29   * Detects inline conditionals. Here is one example of an inline conditional:
30   * </div>
31   * <pre>
32   * String a = getParameter("a");
33   * String b = (a==null || a.length()&lt;1) ? null : a.substring(1);
34   * </pre>
35   *
36   * <p>
37   * Rationale: Some developers find inline conditionals hard to read, so
38   * their employer's coding standards forbid them.
39   * </p>
40   *
41   * <p>
42   * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
43   * </p>
44   *
45   * <p>
46   * Violation Message Keys:
47   * </p>
48   * <ul>
49   * <li>
50   * {@code inline.conditional.avoid}
51   * </li>
52   * </ul>
53   *
54   * @since 3.1
55   */
56  @StatelessCheck
57  public class AvoidInlineConditionalsCheck extends AbstractCheck {
58  
59      /**
60       * A key is pointing to the warning message text in "messages.properties"
61       * file.
62       */
63      public static final String MSG_KEY = "inline.conditional.avoid";
64  
65      @Override
66      public int[] getDefaultTokens() {
67          return getRequiredTokens();
68      }
69  
70      @Override
71      public int[] getRequiredTokens() {
72          return new int[] {TokenTypes.QUESTION};
73      }
74  
75      @Override
76      public int[] getAcceptableTokens() {
77          return getRequiredTokens();
78      }
79  
80      @Override
81      public void visitToken(DetailAST ast) {
82          // the only place a QUESTION token can occur is in inline conditionals
83          // so no need to do any further tricks here - pretty trivial Check!
84  
85          log(ast, MSG_KEY);
86      }
87  
88  }