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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) 2001-2026 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      @Override
88      protected boolean shouldCheckIndentationForChild(DetailAST child) {
89          final DetailAST leftCurly = getLeftCurly();
90          return getFirstAstNode(child).getLineNo() != leftCurly.getLineNo();
91      }
92  
93      /**
94       * Method to check the indentation of left paren or right paren.
95       * This method itself checks whether either of these are on start of line. This method
96       * takes care of line wrapping strict condition as well.
97       *
98       * @param parenAst      lparen or rparen ast to check
99       * @param subType       name to be used in log message
100      */
101     private void checkTryResParen(final DetailAST parenAst,
102                                     final String subType) {
103         if (isOnStartOfLine(parenAst)) {
104             final IndentLevel expectedIdent = new IndentLevel(getIndent(), 0,
105                 getIndentCheck().getLineWrappingIndentation());
106 
107             checkChildIndentation(parenAst, subType, expectedIdent);
108         }
109     }
110 
111     /**
112      * Method to check indentation of try resources children.
113      * It takes into account forceStrictCondition value when logging violations.
114      * Example of usage would include checking for try parenthesis and try resources.
115      *
116      * @param ast           AST to check.
117      * @param subType       String representing child type.
118      * @param expectedIdent Expected indent level.
119      */
120     private void checkChildIndentation(DetailAST ast, String subType, IndentLevel expectedIdent) {
121         if (getIndentCheck().isForceStrictCondition()) {
122             if (!expectedIdent.isAcceptable(expandedTabsColumnNo(ast))) {
123                 logError(ast, subType, expandedTabsColumnNo(ast), expectedIdent);
124             }
125         }
126         else {
127             if (expandedTabsColumnNo(ast) < expectedIdent.getFirstIndentLevel()) {
128                 logError(ast, subType, expandedTabsColumnNo(ast), expectedIdent);
129             }
130         }
131     }
132 
133     /**
134      * Checks indentation of resources parameters in try resources.
135      *
136      * @param resourcesSpecAst   Resource specification ast
137      */
138     private void checkTryResources(final DetailAST resourcesSpecAst) {
139         final DetailAST resourcesAst = resourcesSpecAst.findFirstToken(TokenTypes.RESOURCES);
140         final int indentation = getIndent().getFirstIndentLevel()
141             + getIndentCheck().getLineWrappingIndentation();
142         final IndentLevel expectedResourceIndent = new IndentLevel(indentation);
143 
144         final String subType = "resource";
145 
146         DetailAST resourceAst = resourcesAst.getFirstChild();
147         while (resourceAst != null) {
148             if (resourceAst.getType() == TokenTypes.RESOURCE) {
149                 final DetailAST nextSibling;
150                 if (resourceAst.getNextSibling() == null) {
151                     nextSibling = getTryResRparen();
152                 }
153                 else {
154                     nextSibling = resourceAst.getNextSibling();
155                 }
156                 if (isOnStartOfLine(resourceAst)) {
157                     checkChildIndentation(resourceAst, subType, expectedResourceIndent);
158                     checkWrappingIndentation(
159                         resourceAst,
160                         nextSibling,
161                         getIndentCheck().getLineWrappingIndentation(),
162                         expectedResourceIndent.getFirstIndentLevel(),
163                         true);
164                 }
165                 else {
166                     checkWrappingIndentation(resourceAst, nextSibling);
167                 }
168             }
169             resourceAst = resourceAst.getNextSibling();
170         }
171     }
172 
173     /**
174      * Check if the expression is resource of
175      * <a href="https://docs.oracle.com/javase/specs/jls/se8/html/jls-14.html#jls-14.20.3">
176      * try block</a>.
177      *
178      * @param expression The expression to check
179      * @return if the expression provided is try block's resource specification.
180      */
181     private static boolean isTryBlocksResourceSpecification(AbstractExpressionHandler expression) {
182         boolean isResourceSpecificationExpression = false;
183 
184         DetailAST ast = expression.getMainAst();
185 
186         while (ast.getType() != TokenTypes.LITERAL_TRY) {
187             if (ast.getType() == TokenTypes.RESOURCE_SPECIFICATION) {
188                 isResourceSpecificationExpression = true;
189                 break;
190             }
191 
192             ast = ast.getParent();
193         }
194 
195         return isResourceSpecificationExpression;
196     }
197 
198 }