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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.indentation;
21  
22  import com.puppycrawl.tools.checkstyle.api.DetailAST;
23  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
24  
25  /**
26   * Handler for try blocks.
27   *
28   */
29  public class TryHandler extends BlockParentHandler {
30  
31      /**
32       * Construct an instance of this handler with the given indentation check,
33       * abstract syntax tree, and parent handler.
34       *
35       * @param indentCheck   the indentation check
36       * @param ast           the abstract syntax tree
37       * @param parent        the parent handler
38       */
39      public TryHandler(IndentationCheck indentCheck,
40          DetailAST ast, AbstractExpressionHandler parent) {
41          super(indentCheck, "try", ast, parent);
42      }
43  
44      /**
45       * Method to find left parenthesis of try with resources.
46       *
47       * @return DetailAst    left parenthesis of try with resources
48       */
49      private DetailAST getTryResLparen() {
50          return getMainAst().getFirstChild().getFirstChild();
51      }
52  
53      /**
54       * Method to find right parenthesis of try with resources.
55       *
56       * @return DetailAst    right parenthesis of try with resources
57       */
58      private DetailAST getTryResRparen() {
59          return getMainAst().getFirstChild().getLastChild();
60      }
61  
62      @Override
63      public IndentLevel getSuggestedChildIndent(AbstractExpressionHandler child) {
64          final IndentLevel result;
65          if (child instanceof CatchHandler
66              || child instanceof FinallyHandler
67              || child instanceof NewHandler
68                  && isTryBlocksResourceSpecification(child)) {
69              result = getIndent();
70          }
71          else {
72              result = super.getSuggestedChildIndent(child);
73          }
74          return result;
75      }
76  
77      @Override
78      public void checkIndentation() {
79          super.checkIndentation();
80          if (getMainAst().getFirstChild().getType() == TokenTypes.RESOURCE_SPECIFICATION) {
81              checkTryResParen(getTryResLparen(), "lparen");
82              checkTryResParen(getTryResRparen(), "rparen");
83              checkTryResources(getMainAst().getFirstChild());
84          }
85      }
86  
87      /**
88       * Method to check the indentation of left paren or right paren.
89       * This method itself checks whether either of these are on start of line. This method
90       * takes care of line wrapping strict condition as well.
91       *
92       * @param parenAst      lparen or rparen ast to check
93       * @param subType       name to be used in log message
94       */
95      private void checkTryResParen(final DetailAST parenAst,
96                                      final String subType) {
97          if (isOnStartOfLine(parenAst)) {
98              final IndentLevel expectedIdent = new IndentLevel(getIndent(), 0,
99                  getIndentCheck().getLineWrappingIndentation());
100 
101             checkChildIndentation(parenAst, subType, expectedIdent);
102         }
103     }
104 
105     /**
106      * Method to check indentation of try resources children.
107      * It takes into account forceStrictCondition value when logging violations.
108      * Example of usage would include checking for try parenthesis and try resources.
109      *
110      * @param ast           AST to check.
111      * @param subType       String representing child type.
112      * @param expectedIdent Expected indent level.
113      */
114     private void checkChildIndentation(DetailAST ast, String subType, IndentLevel expectedIdent) {
115         if (getIndentCheck().isForceStrictCondition()) {
116             if (!expectedIdent.isAcceptable(expandedTabsColumnNo(ast))) {
117                 logError(ast, subType, expandedTabsColumnNo(ast), expectedIdent);
118             }
119         }
120         else {
121             if (expandedTabsColumnNo(ast) < expectedIdent.getFirstIndentLevel()) {
122                 logError(ast, subType, expandedTabsColumnNo(ast), expectedIdent);
123             }
124         }
125     }
126 
127     /**
128      * Checks indentation of resources parameters in try resources.
129      *
130      * @param resourcesSpecAst   Resource specification ast
131      */
132     private void checkTryResources(final DetailAST resourcesSpecAst) {
133         final DetailAST resourcesAst = resourcesSpecAst.findFirstToken(TokenTypes.RESOURCES);
134         final int indentation = getIndent().getFirstIndentLevel()
135             + getIndentCheck().getLineWrappingIndentation();
136         final IndentLevel expectedResourceIndent = new IndentLevel(indentation);
137 
138         final String subType = "resource";
139 
140         DetailAST resourceAst = resourcesAst.getFirstChild();
141         while (resourceAst != null) {
142             if (resourceAst.getType() == TokenTypes.RESOURCE) {
143                 final DetailAST nextSibling;
144                 if (resourceAst.getNextSibling() == null) {
145                     nextSibling = getTryResRparen();
146                 }
147                 else {
148                     nextSibling = resourceAst.getNextSibling();
149                 }
150                 if (isOnStartOfLine(resourceAst)) {
151                     checkChildIndentation(resourceAst, subType, expectedResourceIndent);
152                     checkWrappingIndentation(
153                         resourceAst,
154                         nextSibling,
155                         getIndentCheck().getLineWrappingIndentation(),
156                         expectedResourceIndent.getFirstIndentLevel(),
157                         true);
158                 }
159                 else {
160                     checkWrappingIndentation(resourceAst, nextSibling);
161                 }
162             }
163             resourceAst = resourceAst.getNextSibling();
164         }
165     }
166 
167     /**
168      * Check if the expression is resource of
169      * <a href="https://docs.oracle.com/javase/specs/jls/se8/html/jls-14.html#jls-14.20.3">
170      * try block</a>.
171      *
172      * @param expression The expression to check
173      * @return if the expression provided is try block's resource specification.
174      */
175     private static boolean isTryBlocksResourceSpecification(AbstractExpressionHandler expression) {
176         boolean isResourceSpecificationExpression = false;
177 
178         DetailAST ast = expression.getMainAst();
179 
180         while (ast.getType() != TokenTypes.LITERAL_TRY) {
181             if (ast.getType() == TokenTypes.RESOURCE_SPECIFICATION) {
182                 isResourceSpecificationExpression = true;
183                 break;
184             }
185 
186             ast = ast.getParent();
187         }
188 
189         return isResourceSpecificationExpression;
190     }
191 
192 }