001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2025 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;
029import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
030
031/**
032 * <div>
033 * Checks that overloaded methods are grouped together. Overloaded methods have the same
034 * name but different signatures where the signature can differ by the number of
035 * input parameters or type of input parameters or both.
036 * </div>
037 *
038 * <p>
039 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
040 * </p>
041 *
042 * <p>
043 * Violation Message Keys:
044 * </p>
045 * <ul>
046 * <li>
047 * {@code overload.methods.declaration}
048 * </li>
049 * </ul>
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
083        final int[] tokenTypes = {
084            TokenTypes.CLASS_DEF,
085            TokenTypes.ENUM_DEF,
086            TokenTypes.INTERFACE_DEF,
087            TokenTypes.LITERAL_NEW,
088            TokenTypes.RECORD_DEF,
089        };
090
091        if (TokenUtil.isOfType(parentType, tokenTypes)) {
092            checkOverloadMethodsGrouping(ast);
093        }
094    }
095
096    /**
097     * Checks that if overload methods are grouped together they should not be
098     * separated from each other.
099     *
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}