View Javadoc
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 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   * @author maxvetrenko
50   */
51  @StatelessCheck
52  public class OverloadMethodsDeclarationOrderCheck extends AbstractCheck {
53  
54      /**
55       * A key is pointing to the warning message text in "messages.properties"
56       * file.
57       */
58      public static final String MSG_KEY = "overload.methods.declaration";
59  
60      @Override
61      public int[] getDefaultTokens() {
62          return getRequiredTokens();
63      }
64  
65      @Override
66      public int[] getAcceptableTokens() {
67          return getRequiredTokens();
68      }
69  
70      @Override
71      public int[] getRequiredTokens() {
72          return new int[] {
73              TokenTypes.OBJBLOCK,
74          };
75      }
76  
77      @Override
78      public void visitToken(DetailAST ast) {
79          final int parentType = ast.getParent().getType();
80          if (parentType == TokenTypes.CLASS_DEF
81                  || parentType == TokenTypes.ENUM_DEF
82                  || parentType == TokenTypes.INTERFACE_DEF
83                  || parentType == TokenTypes.LITERAL_NEW) {
84              checkOverloadMethodsGrouping(ast);
85          }
86      }
87  
88      /**
89       * Checks that if overload methods are grouped together they should not be
90       * separated from each other.
91       * @param objectBlock
92       *        is a class, interface or enum object block.
93       */
94      private void checkOverloadMethodsGrouping(DetailAST objectBlock) {
95          final int allowedDistance = 1;
96          DetailAST currentToken = objectBlock.getFirstChild();
97          final Map<String, Integer> methodIndexMap = new HashMap<>();
98          final Map<String, Integer> methodLineNumberMap = new HashMap<>();
99          int currentIndex = 0;
100         while (currentToken != null) {
101             if (currentToken.getType() == TokenTypes.METHOD_DEF) {
102                 currentIndex++;
103                 final String methodName =
104                         currentToken.findFirstToken(TokenTypes.IDENT).getText();
105                 if (methodIndexMap.containsKey(methodName)) {
106                     final int previousIndex = methodIndexMap.get(methodName);
107                     if (currentIndex - previousIndex > allowedDistance) {
108                         final int previousLineWithOverloadMethod =
109                                 methodLineNumberMap.get(methodName);
110                         log(currentToken.getLineNo(), MSG_KEY,
111                                 previousLineWithOverloadMethod);
112                     }
113                 }
114                 methodIndexMap.put(methodName, currentIndex);
115                 methodLineNumberMap.put(methodName, currentToken.getLineNo());
116             }
117             currentToken = currentToken.getNextSibling();
118         }
119     }
120 }