001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2015 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.Check;
023import com.puppycrawl.tools.checkstyle.api.DetailAST;
024import com.puppycrawl.tools.checkstyle.api.TokenTypes;
025
026/**
027 * <p>
028 * Checks if array initialization contains optional trailing comma.
029 * </p>
030 * <p>
031 * Rationale: Putting this comma in make is easier to change the
032 * order of the elements or add new elements on the end.
033 * </p>
034 * <p>
035 * An example of how to configure the check is:
036 * </p>
037 * <pre>
038 * &lt;module name="ArrayTrailingComma"/&gt;
039 * </pre>
040 * @author o_sukhodolsky
041 */
042public class ArrayTrailingCommaCheck extends Check {
043
044    /**
045     * A key is pointing to the warning message text in "messages.properties"
046     * file.
047     */
048    public static final String MSG_KEY = "array.trailing.comma";
049
050    @Override
051    public int[] getDefaultTokens() {
052        return getAcceptableTokens();
053    }
054
055    @Override
056    public int[] getAcceptableTokens() {
057        return new int[] {TokenTypes.ARRAY_INIT};
058    }
059
060    @Override
061    public int[] getRequiredTokens() {
062        return getAcceptableTokens();
063    }
064
065    @Override
066    public void visitToken(DetailAST arrayInit) {
067        final DetailAST rcurly = arrayInit.findFirstToken(TokenTypes.RCURLY);
068
069        // if curlies are on the same line
070        // or array is empty then check nothing
071        if (arrayInit.getLineNo() == rcurly.getLineNo()
072            || arrayInit.getChildCount() == 1) {
073            return;
074        }
075
076        final DetailAST prev = rcurly.getPreviousSibling();
077        if (prev.getType() != TokenTypes.COMMA) {
078            log(rcurly.getLineNo(), MSG_KEY);
079        }
080    }
081}