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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 java.util.HashMap;
23  import java.util.Map;
24  
25  import com.puppycrawl.tools.checkstyle.StatelessCheck;
26  import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
27  import com.puppycrawl.tools.checkstyle.api.DetailAST;
28  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
29  import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
30  
31  /**
32   * <div>
33   * Checks that overloaded methods are grouped together. Overloaded methods have the same
34   * name but different signatures where the signature can differ by the number of
35   * input parameters or type of input parameters or both.
36   * </div>
37   *
38   * <p>
39   * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
40   * </p>
41   *
42   * <p>
43   * Violation Message Keys:
44   * </p>
45   * <ul>
46   * <li>
47   * {@code overload.methods.declaration}
48   * </li>
49   * </ul>
50   *
51   * @since 5.8
52   */
53  @StatelessCheck
54  public class OverloadMethodsDeclarationOrderCheck 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 = "overload.methods.declaration";
61  
62      @Override
63      public int[] getDefaultTokens() {
64          return getRequiredTokens();
65      }
66  
67      @Override
68      public int[] getAcceptableTokens() {
69          return getRequiredTokens();
70      }
71  
72      @Override
73      public int[] getRequiredTokens() {
74          return new int[] {
75              TokenTypes.OBJBLOCK,
76          };
77      }
78  
79      @Override
80      public void visitToken(DetailAST ast) {
81          final int parentType = ast.getParent().getType();
82  
83          final int[] tokenTypes = {
84              TokenTypes.CLASS_DEF,
85              TokenTypes.ENUM_DEF,
86              TokenTypes.INTERFACE_DEF,
87              TokenTypes.LITERAL_NEW,
88              TokenTypes.RECORD_DEF,
89          };
90  
91          if (TokenUtil.isOfType(parentType, tokenTypes)) {
92              checkOverloadMethodsGrouping(ast);
93          }
94      }
95  
96      /**
97       * Checks that if overload methods are grouped together they should not be
98       * separated from each other.
99       *
100      * @param objectBlock
101      *        is a class, interface or enum object block.
102      */
103     private void checkOverloadMethodsGrouping(DetailAST objectBlock) {
104         final int allowedDistance = 1;
105         DetailAST currentToken = objectBlock.getFirstChild();
106         final Map<String, Integer> methodIndexMap = new HashMap<>();
107         final Map<String, Integer> methodLineNumberMap = new HashMap<>();
108         int currentIndex = 0;
109         while (currentToken != null) {
110             if (currentToken.getType() == TokenTypes.METHOD_DEF) {
111                 currentIndex++;
112                 final String methodName =
113                         currentToken.findFirstToken(TokenTypes.IDENT).getText();
114                 final Integer previousIndex = methodIndexMap.get(methodName);
115                 final DetailAST previousSibling = currentToken.getPreviousSibling();
116                 final boolean isMethod = previousSibling.getType() == TokenTypes.METHOD_DEF;
117 
118                 if (previousIndex != null
119                         && (!isMethod || currentIndex - previousIndex > allowedDistance)) {
120                     final int previousLineWithOverloadMethod =
121                             methodLineNumberMap.get(methodName);
122                     log(currentToken, MSG_KEY,
123                             previousLineWithOverloadMethod);
124                 }
125                 methodIndexMap.put(methodName, currentIndex);
126                 methodLineNumberMap.put(methodName, currentToken.getLineNo());
127             }
128             currentToken = currentToken.getNextSibling();
129         }
130     }
131 
132 }