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 com.puppycrawl.tools.checkstyle.api.AbstractCheck;
023import com.puppycrawl.tools.checkstyle.api.DetailAST;
024import com.puppycrawl.tools.checkstyle.api.TokenTypes;
025
026/**
027 * Checks that no method having zero parameters is defined
028 * using the name <em>finalize</em>.
029 *
030 * @author fqian@google.com (Feng Qian)
031 * @author smckay@google.com (Steve McKay)
032 * @author lkuehne
033 */
034public class NoFinalizerCheck extends AbstractCheck {
035
036    /**
037     * A key is pointing to the warning message text in "messages.properties"
038     * file.
039     */
040    public static final String MSG_KEY = "avoid.finalizer.method";
041
042    @Override
043    public int[] getDefaultTokens() {
044        return getAcceptableTokens();
045    }
046
047    @Override
048    public int[] getAcceptableTokens() {
049        return new int[] {TokenTypes.METHOD_DEF};
050    }
051
052    @Override
053    public int[] getRequiredTokens() {
054        return getAcceptableTokens();
055    }
056
057    @Override
058    public void visitToken(DetailAST aAST) {
059        final DetailAST mid = aAST.findFirstToken(TokenTypes.IDENT);
060        final String name = mid.getText();
061
062        if ("finalize".equals(name)) {
063
064            final DetailAST params = aAST.findFirstToken(TokenTypes.PARAMETERS);
065            final boolean hasEmptyParamList =
066                !params.branchContains(TokenTypes.PARAMETER_DEF);
067
068            if (hasEmptyParamList) {
069                log(aAST.getLineNo(), MSG_KEY);
070            }
071        }
072    }
073}