001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2020 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.checks.coding;
021
022import java.util.HashMap;
023import java.util.Map;
024
025import com.puppycrawl.tools.checkstyle.StatelessCheck;
026import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
027import com.puppycrawl.tools.checkstyle.api.DetailAST;
028import com.puppycrawl.tools.checkstyle.api.TokenTypes;
029
030/**
031 * <p>
032 * Checks that overload methods are grouped together.
033 * </p>
034 * <p>
035 * Example of incorrect grouping overload methods:
036 * </p>
037 * <pre>
038 * public void foo(int i) {}
039 * public void foo(String s) {}
040 * public void notFoo() {} // Have to be after foo(int i, String s)
041 * public void foo(int i, String s) {}
042 * </pre>
043 * <p>
044 * An example of how to configure the check is:
045 * </p>
046 *
047 * <pre>
048 * &lt;module name=&quot;OverloadMethodsDeclarationOrder&quot;/&gt;
049 * </pre>
050 *
051 * @since 5.8
052 */
053@StatelessCheck
054public class OverloadMethodsDeclarationOrderCheck extends AbstractCheck {
055
056    /**
057     * A key is pointing to the warning message text in "messages.properties"
058     * file.
059     */
060    public static final String MSG_KEY = "overload.methods.declaration";
061
062    @Override
063    public int[] getDefaultTokens() {
064        return getRequiredTokens();
065    }
066
067    @Override
068    public int[] getAcceptableTokens() {
069        return getRequiredTokens();
070    }
071
072    @Override
073    public int[] getRequiredTokens() {
074        return new int[] {
075            TokenTypes.OBJBLOCK,
076        };
077    }
078
079    @Override
080    public void visitToken(DetailAST ast) {
081        final int parentType = ast.getParent().getType();
082        if (parentType == TokenTypes.CLASS_DEF
083                || parentType == TokenTypes.ENUM_DEF
084                || parentType == TokenTypes.INTERFACE_DEF
085                || parentType == TokenTypes.LITERAL_NEW) {
086            checkOverloadMethodsGrouping(ast);
087        }
088    }
089
090    /**
091     * Checks that if overload methods are grouped together they should not be
092     * separated from each other.
093     * @param objectBlock
094     *        is a class, interface or enum object block.
095     */
096    private void checkOverloadMethodsGrouping(DetailAST objectBlock) {
097        final int allowedDistance = 1;
098        DetailAST currentToken = objectBlock.getFirstChild();
099        final Map<String, Integer> methodIndexMap = new HashMap<>();
100        final Map<String, Integer> methodLineNumberMap = new HashMap<>();
101        int currentIndex = 0;
102        while (currentToken != null) {
103            if (currentToken.getType() == TokenTypes.METHOD_DEF) {
104                currentIndex++;
105                final String methodName =
106                        currentToken.findFirstToken(TokenTypes.IDENT).getText();
107                if (methodIndexMap.containsKey(methodName)) {
108                    final int previousIndex = methodIndexMap.get(methodName);
109                    if (currentIndex - previousIndex > allowedDistance) {
110                        final int previousLineWithOverloadMethod =
111                                methodLineNumberMap.get(methodName);
112                        log(currentToken.getLineNo(), MSG_KEY,
113                                previousLineWithOverloadMethod);
114                    }
115                }
116                methodIndexMap.put(methodName, currentIndex);
117                methodLineNumberMap.put(methodName, currentToken.getLineNo());
118            }
119            currentToken = currentToken.getNextSibling();
120        }
121    }
122
123}