001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2017 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 * @author maxvetrenko
050 */
051@StatelessCheck
052public class OverloadMethodsDeclarationOrderCheck extends AbstractCheck {
053
054    /**
055     * A key is pointing to the warning message text in "messages.properties"
056     * file.
057     */
058    public static final String MSG_KEY = "overload.methods.declaration";
059
060    @Override
061    public int[] getDefaultTokens() {
062        return getRequiredTokens();
063    }
064
065    @Override
066    public int[] getAcceptableTokens() {
067        return getRequiredTokens();
068    }
069
070    @Override
071    public int[] getRequiredTokens() {
072        return new int[] {
073            TokenTypes.OBJBLOCK,
074        };
075    }
076
077    @Override
078    public void visitToken(DetailAST ast) {
079        final int parentType = ast.getParent().getType();
080        if (parentType == TokenTypes.CLASS_DEF
081                || parentType == TokenTypes.ENUM_DEF
082                || parentType == TokenTypes.INTERFACE_DEF
083                || parentType == TokenTypes.LITERAL_NEW) {
084            checkOverloadMethodsGrouping(ast);
085        }
086    }
087
088    /**
089     * Checks that if overload methods are grouped together they should not be
090     * separated from each other.
091     * @param objectBlock
092     *        is a class, interface or enum object block.
093     */
094    private void checkOverloadMethodsGrouping(DetailAST objectBlock) {
095        final int allowedDistance = 1;
096        DetailAST currentToken = objectBlock.getFirstChild();
097        final Map<String, Integer> methodIndexMap = new HashMap<>();
098        final Map<String, Integer> methodLineNumberMap = new HashMap<>();
099        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}