com.puppycrawl.tools.checkstyle.checks.coding.DefaultComesLastCheck Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of checkstyle Show documentation

Checkstyle is a development tool to help programmers write Java code that adheres to a coding standard

There is a newer version: 10.21.1

////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2016 the original author or authors.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
////////////////////////////////////////////////////////////////////////////////

package com.puppycrawl.tools.checkstyle.checks.coding;

import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;

/**
 * 
 * Check that the {@code default} is after all the {@code case}s
 * in a {@code switch} statement.
 * 
 * 
 * Rationale: Java allows {@code default} anywhere within the
 * {@code switch} statement. But if it comes after the last
 * {@code case} then it is more readable.
 * 
 * 
 * An example of how to configure the check is:
 * 
 *  * <module name="DefaultComesLast"/>
 * 
 * @author o_sukhodolsky
 */
public class DefaultComesLastCheck extends AbstractCheck {

    /**
     * A key is pointing to the warning message text in "messages.properties"
     * file.
     */
    public static final String MSG_KEY = "default.comes.last";

    @Override
    public int[] getAcceptableTokens() {
        return new int[] {
            TokenTypes.LITERAL_DEFAULT,
        };
    }

    @Override
    public int[] getDefaultTokens() {
        return getAcceptableTokens();
    }

    @Override
    public int[] getRequiredTokens() {
        return getAcceptableTokens();
    }

    @Override
    public void visitToken(DetailAST ast) {
        final DetailAST defaultGroupAST = ast.getParent();
        //default keywords used in annotations too - not what we're
        //interested in
        if (defaultGroupAST.getType() != TokenTypes.ANNOTATION_FIELD_DEF
                && defaultGroupAST.getType() != TokenTypes.MODIFIERS) {
            final DetailAST switchAST = defaultGroupAST.getParent();
            final DetailAST lastGroupAST =
                switchAST.getLastChild().getPreviousSibling();

            if (defaultGroupAST.getLineNo() != lastGroupAST.getLineNo()
                || defaultGroupAST.getColumnNo()
                    != lastGroupAST.getColumnNo()) {
                log(ast, MSG_KEY);
            }
        }
    }
}