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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 com.puppycrawl.tools.checkstyle.FileStatefulCheck;
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   * Restricts nested try-catch-finally blocks to a specified depth (default = 1).
29   * @author <a href="mailto:simon@redhillconsulting.com.au">Simon Harris</a>
30   */
31  @FileStatefulCheck
32  public final class NestedTryDepthCheck extends AbstractCheck {
33  
34      /**
35       * A key is pointing to the warning message text in "messages.properties"
36       * file.
37       */
38      public static final String MSG_KEY = "nested.try.depth";
39  
40      /** Maximum allowed nesting depth. */
41      private int max = 1;
42      /** Current nesting depth. */
43      private int depth;
44  
45      /**
46       * Setter for maximum allowed nesting depth.
47       * @param max maximum allowed nesting depth.
48       */
49      public void setMax(int max) {
50          this.max = max;
51      }
52  
53      @Override
54      public int[] getDefaultTokens() {
55          return getRequiredTokens();
56      }
57  
58      @Override
59      public int[] getAcceptableTokens() {
60          return getRequiredTokens();
61      }
62  
63      @Override
64      public int[] getRequiredTokens() {
65          return new int[] {TokenTypes.LITERAL_TRY};
66      }
67  
68      @Override
69      public void beginTree(DetailAST rootAST) {
70          depth = 0;
71      }
72  
73      @Override
74      public void visitToken(DetailAST literalTry) {
75          if (depth > max) {
76              log(literalTry, MSG_KEY, depth, max);
77          }
78          ++depth;
79      }
80  
81      @Override
82      public void leaveToken(DetailAST literalTry) {
83          --depth;
84      }
85  
86  }