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