001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2018 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. Example:
033 * </p>
034 * <pre>
035 * {@code
036 * public void foo(int i) {}
037 * public void foo(String s) {}
038 * public void notFoo() {} // Have to be after foo(int i, String s)
039 * public void foo(int i, String s) {}
040 * }
041 * </pre>
042 * <p>
043 * An example of how to configure the check is:
044 * </p>
045 *
046 * <pre>
047 * &lt;module name="OverloadMethodsDeclarationOrder"/&gt;
048 * </pre>
049 */
050@StatelessCheck
051public class OverloadMethodsDeclarationOrderCheck extends AbstractCheck {
052
053    /**
054     * A key is pointing to the warning message text in "messages.properties"
055     * file.
056     */
057    public static final String MSG_KEY = "overload.methods.declaration";
058
059    @Override
060    public int[] getDefaultTokens() {
061        return getRequiredTokens();
062    }
063
064    @Override
065    public int[] getAcceptableTokens() {
066        return getRequiredTokens();
067    }
068
069    @Override
070    public int[] getRequiredTokens() {
071        return new int[] {
072            TokenTypes.OBJBLOCK,
073        };
074    }
075
076    @Override
077    public void visitToken(DetailAST ast) {
078        final int parentType = ast.getParent().getType();
079        if (parentType == TokenTypes.CLASS_DEF
080                || parentType == TokenTypes.ENUM_DEF
081                || parentType == TokenTypes.INTERFACE_DEF
082                || parentType == TokenTypes.LITERAL_NEW) {
083            checkOverloadMethodsGrouping(ast);
084        }
085    }
086
087    /**
088     * Checks that if overload methods are grouped together they should not be
089     * separated from each other.
090     * @param objectBlock
091     *        is a class, interface or enum object block.
092     */
093    private void checkOverloadMethodsGrouping(DetailAST objectBlock) {
094        final int allowedDistance = 1;
095        DetailAST currentToken = objectBlock.getFirstChild();
096        final Map<String, Integer> methodIndexMap = new HashMap<>();
097        final Map<String, Integer> methodLineNumberMap = new HashMap<>();
098        int currentIndex = 0;
099        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}