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

////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2015 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 org.apache.commons.lang3.ArrayUtils;

import com.puppycrawl.tools.checkstyle.api.Check;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import com.puppycrawl.tools.checkstyle.utils.TokenUtils;

/**
 * 
 * Checks for illegal tokens. By default labels are prohibited.
 * 
 * 
 * Rationale: Certain language features can harm readability, lead to
 * confusion or are not obvious to novice developers. Other features
 * may be discouraged in certain frameworks, such as not having
 * native methods in EJB components.
 * 
 * 
 * An example of how to configure the check is:
 * 
 *  * <module name="IllegalToken"/>
 * 
 *  An example of how to configure the check to forbid
 * a {@link TokenTypes#LITERAL_NATIVE LITERAL_NATIVE} token is:
 * 
 *  * <module name="IllegalToken">
 *     <property name="tokens" value="LITERAL_NATIVE"/>
 * </module>
 * 
 * @author Simon Harris
 * @author Rick Giles
 */
public class IllegalTokenCheck
    extends Check {

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

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

    @Override
    public int[] getAcceptableTokens() {
        return TokenUtils.getAllTokenIds();
    }

    @Override
    public int[] getRequiredTokens() {
        return ArrayUtils.EMPTY_INT_ARRAY;
    }

    @Override
    public void visitToken(DetailAST ast) {
        log(
            ast.getLineNo(),
            ast.getColumnNo(),
            MSG_KEY,
            convertToString(ast)
        );
    }

    /**
     * Converts given AST node to string representation.
     * @param ast node to be represented as string
     * @return string representation of AST node
     */
    private static String convertToString(DetailAST ast) {
        final String tokenText;
        if (ast.getType() == TokenTypes.LABELED_STAT) {
            tokenText = ast.getFirstChild().getText() + ast.getText();
        }
        else {
            tokenText = ast.getText();
        }
        return tokenText;
    }

}