1   ////////////////////////////////////////////////////////////////////////////////
2   // checkstyle: Checks Java source code for adherence to a set of rules.
3   // Copyright (C) 2001-2019 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  
30  /**
31   * <p>
32   * Checks that overload methods are grouped together. Example:
33   * </p>
34   * <pre>
35   * {@code
36   * public void foo(int i) {}
37   * public void foo(String s) {}
38   * public void notFoo() {} // Have to be after foo(int i, String s)
39   * public void foo(int i, String s) {}
40   * }
41   * </pre>
42   * <p>
43   * An example of how to configure the check is:
44   * </p>
45   *
46   * <pre>
47   * &lt;module name="OverloadMethodsDeclarationOrder"/&gt;
48   * </pre>
49   */
50  @StatelessCheck
51  public class OverloadMethodsDeclarationOrderCheck extends AbstractCheck {
52  
53      /**
54       * A key is pointing to the warning message text in "messages.properties"
55       * file.
56       */
57      public static final String MSG_KEY = "overload.methods.declaration";
58  
59      @Override
60      public int[] getDefaultTokens() {
61          return getRequiredTokens();
62      }
63  
64      @Override
65      public int[] getAcceptableTokens() {
66          return getRequiredTokens();
67      }
68  
69      @Override
70      public int[] getRequiredTokens() {
71          return new int[] {
72              TokenTypes.OBJBLOCK,
73          };
74      }
75  
76      @Override
77      public void visitToken(DetailAST ast) {
78          final int parentType = ast.getParent().getType();
79          if (parentType == TokenTypes.CLASS_DEF
80                  || parentType == TokenTypes.ENUM_DEF
81                  || parentType == TokenTypes.INTERFACE_DEF
82                  || parentType == TokenTypes.LITERAL_NEW) {
83              checkOverloadMethodsGrouping(ast);
84          }
85      }
86  
87      /**
88       * Checks that if overload methods are grouped together they should not be
89       * separated from each other.
90       * @param objectBlock
91       *        is a class, interface or enum object block.
92       */
93      private void checkOverloadMethodsGrouping(DetailAST objectBlock) {
94          final int allowedDistance = 1;
95          DetailAST currentToken = objectBlock.getFirstChild();
96          final Map<String, Integer> methodIndexMap = new HashMap<>();
97          final Map<String, Integer> methodLineNumberMap = new HashMap<>();
98          int currentIndex = 0;
99          while (currentToken != null) {
100             if (currentToken.getType() == TokenTypes.METHOD_DEF) {
101                 currentIndex++;
102                 final String methodName =
103                         currentToken.findFirstToken(TokenTypes.IDENT).getText();
104                 if (methodIndexMap.containsKey(methodName)) {
105                     final int previousIndex = methodIndexMap.get(methodName);
106                     if (currentIndex - previousIndex > allowedDistance) {
107                         final int previousLineWithOverloadMethod =
108                                 methodLineNumberMap.get(methodName);
109                         log(currentToken.getLineNo(), MSG_KEY,
110                                 previousLineWithOverloadMethod);
111                     }
112                 }
113                 methodIndexMap.put(methodName, currentIndex);
114                 methodLineNumberMap.put(methodName, currentToken.getLineNo());
115             }
116             currentToken = currentToken.getNextSibling();
117         }
118     }
119 
120 }