001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2019 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 com.puppycrawl.tools.checkstyle.StatelessCheck;
023import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
024import com.puppycrawl.tools.checkstyle.api.DetailAST;
025import com.puppycrawl.tools.checkstyle.api.TokenTypes;
026
027/**
028 * Checks that no method having zero parameters is defined
029 * using the name <em>finalize</em>.
030 *
031 */
032@StatelessCheck
033public class NoFinalizerCheck extends AbstractCheck {
034
035    /**
036     * A key is pointing to the warning message text in "messages.properties"
037     * file.
038     */
039    public static final String MSG_KEY = "avoid.finalizer.method";
040
041    @Override
042    public int[] getDefaultTokens() {
043        return getRequiredTokens();
044    }
045
046    @Override
047    public int[] getAcceptableTokens() {
048        return getRequiredTokens();
049    }
050
051    @Override
052    public int[] getRequiredTokens() {
053        return new int[] {TokenTypes.METHOD_DEF};
054    }
055
056    @Override
057    public void visitToken(DetailAST aAST) {
058        final DetailAST mid = aAST.findFirstToken(TokenTypes.IDENT);
059        final String name = mid.getText();
060
061        if ("finalize".equals(name)) {
062            final DetailAST params = aAST.findFirstToken(TokenTypes.PARAMETERS);
063            final boolean hasEmptyParamList =
064                params.findFirstToken(TokenTypes.PARAMETER_DEF) == null;
065
066            if (hasEmptyParamList) {
067                log(aAST.getLineNo(), MSG_KEY);
068            }
069        }
070    }
071
072}