001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2016 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 * <p>
028 * Check that the {@code default} is after all the {@code case}s
029 * in a {@code switch} statement.
030 * </p>
031 * <p>
032 * Rationale: Java allows {@code default} anywhere within the
033 * {@code switch} statement. But if it comes after the last
034 * {@code case} then it is more readable.
035 * </p>
036 * <p>
037 * An example of how to configure the check is:
038 * </p>
039 * <pre>
040 * &lt;module name="DefaultComesLast"/&gt;
041 * </pre>
042 * @author o_sukhodolsky
043 */
044public class DefaultComesLastCheck extends AbstractCheck {
045
046    /**
047     * A key is pointing to the warning message text in "messages.properties"
048     * file.
049     */
050    public static final String MSG_KEY = "default.comes.last";
051
052    @Override
053    public int[] getAcceptableTokens() {
054        return new int[] {
055            TokenTypes.LITERAL_DEFAULT,
056        };
057    }
058
059    @Override
060    public int[] getDefaultTokens() {
061        return getAcceptableTokens();
062    }
063
064    @Override
065    public int[] getRequiredTokens() {
066        return getAcceptableTokens();
067    }
068
069    @Override
070    public void visitToken(DetailAST ast) {
071        final DetailAST defaultGroupAST = ast.getParent();
072        //default keywords used in annotations too - not what we're
073        //interested in
074        if (defaultGroupAST.getType() != TokenTypes.ANNOTATION_FIELD_DEF
075                && defaultGroupAST.getType() != TokenTypes.MODIFIERS) {
076            final DetailAST switchAST = defaultGroupAST.getParent();
077            final DetailAST lastGroupAST =
078                switchAST.getLastChild().getPreviousSibling();
079
080            if (defaultGroupAST.getLineNo() != lastGroupAST.getLineNo()
081                || defaultGroupAST.getColumnNo()
082                    != lastGroupAST.getColumnNo()) {
083                log(ast, MSG_KEY);
084            }
085        }
086    }
087}